IUPAC Glossary of terms used in neurotoxicology (IUPAC Recommendations 2015)

CONTENTS

Preface

A major goal of IUPAC is to promote “regulation, standardization, or codification” globally in relevant areas of chemistry. To this end, the Division of Chemistry and Human Health (Division VII), recognizing the importance of toxicology to chemists, produced the Glossary of Terms Used in Toxicology, 2^nd ed., in 2007 [1]. That glossary was intended to provide clear and concise definitions for a range of terms in toxicology and toxicokinetics, primarily for chemists who find themselves working in toxicology or requiring a working knowledge of the subject. It was also recognized that other scientists, regulators, and managers must from time to time interpret toxicological information, and it was hoped that the Glossary would also provide them with ready access to internationally accepted definitions of relevant terms. A number of subspecialties have broadened the scope of toxicology; in 2009 the Division expanded the collection of available definitions with publication of a Glossary of Terms Used in Ecotoxicology [2], and again in 2012 with a Glossary of Terms Used in Immunotoxicology [3].

In the years since publication of the 2^nd edition of the general glossary, we have recognized that a number of the terms continue to evolve and definitions need periodic refinement. It is also apparent that now a searchable, electronic database updating and combining entries from the previous glossaries is desirable, and achievable. A project to achieve this is underway, but at its inception we realized that some areas of toxicology had been under-represented, and addressing this deficit would enhance the usefulness of the database. One area felt to be under-represented was neurotoxicology, and the present document is an attempt to address this deficit. Intended to stand alone as an IUPAC Recommendation in the narrower field, it is also destined for integration into the revised, online Glossary of Terms Used in Toxicology, currently under construction.

In order to minimize the reader’s time in consulting additional texts, terms from [1] were included when it was felt that they were used with particular frequency in neurotoxicology. The authors have also exercised judgment in deciding which terms from basic neuroscience should be included for the reader’s convenience. Given the highly medical nature of the subject, it has been necessary to include a number of medical terms, both clinical and anatomic. In the spirit of producing a document primarily useful for chemists and allied professionals, we have tried not to be over-inclusive in this regard, yet including terms that may be encountered with reasonable frequency in the literature of neurotoxicology of substances. When a medical term is defined, we have tried to provide a brief, useful definition that is nevertheless accurate in terms of current medical understanding.

In general, commonly preferred or American spelling has been adopted for the main entry terms; thus, for example, anesthetic (not anaesthetic), adrenalin (not adrenaline), neuron (not neurone), disc (not disk), and tumor (not tumour). Further, somewhat arbitrary decisions must be made in listing alternative forms of terms as the main entry (e.g., vasospasm instead of angiospasm, β-blocker instead of β-antagonist, and intervertebral disc rather than spinal disc). We have generally tried to use the form we find to be in most common usage, and cross-reference the least-used term if it seems also common, but if a desired entry is not found under one construction, it should be sought under the other.

Many definitions have been compiled from earlier sources, with or without modification, as indicated in the citation. When no citation is given, the term is newly defined. When a citation is given, the definition is more or less a quotation from the original. With the qualification “After,” the general concept of the original has been retained with some rewording, often for consistency with IUPAC guidelines for glossaries. “Modified from” implies a concept specific to the source is retained but put into original wording. When a citation is indented following a Note, it refers only to the Note.

The document has been put together with invaluable input from many colleagues and expert reviewers. Where flaws remain, they are the responsibility of the authors.

Acknowledgments

Many reviewers contributed to the final content of this Glossary, some anonymously and some not, depending on the stage of the process. Among the latter, special thanks are due to Dr. Jean Harry, whose many suggestions and line-by-line commentary significantly shaped the final outcome. Very helpful guidance was also given by Prof. Aaron Bowman, Dr. William Boyes, Prof. Bernard Weiss and Dr. Steven Gilbert. A debt of gratitude is also owing to Prof. Philippe Grandjean, who suggested modifications to a later draft, and to Prof. Rita Cornelis for extensive editorial comment on the penultimate version.

Alphabetical entries

acclimation

acclimatization

Adjustment, physiologically and (or) behaviorally, of an organism to its environment or circumstances, e.g., thermoregulation, psychological adjustment.

acclimatization

See acclimation.

acetylcholine (ACh)

2-acetoxy-N,N,N-trimethylethanaminium

Substance that functions as a neurotransmitter between nerve cells and between nerves and muscles.

acetylcholinesterase (AChE)

acetylcholine hydrolase

Enzyme that hydrolyzes acetylcholine.

acetylcholine receptor

Integral membrane protein that allows the cell to respond to the binding of acetylcholine.

acoustic neuroma

acoustic neurinoma

vestibular Schwannoma

Non-malignant intracranialtumor of the eighth cranial nerve.

acroparesthesia

Abnormal feeling of numbness, tingling, or burning of the skin, typically in the extremities.

action potential

Brief, spike-like depolarization associated with the passage of an impulse without decrement along the membrane of a muscle cell or nerve cell.

active avoidance test

Fear-motivated associative avoidance test based on presentation of an adverse stimulus (e.g., an electric current) as a source of discomfort, to create an environment from which the animal or subject would prefer to escape.

After [4]

addiction

Compulsive, uncontrolled reward-seeking behavior, especially referring to substance use.

See also habituation.

adenoma

Benign tumor arising from epithelial cells in glandular tissue.

adenosine receptor

Any of four types of purinergic receptors that respond to the nucleoside, adenosine, two of which are involved in release of the neurotransmitters, dopamine and glutamate.

adrenalin

adrenaline

epinephrine

(R)-4-(1-hydroxy-2-(methylamino)ethyl)benzene-1,2-diol

Catecholamine hormone secreted by the adrenal glands that increases heart rate, breathing rate, blood pressure, and carbohydrate metabolism.

See noradrenalin.

adrenergic

1. Relating to or denoting secretion of and (or) response to adrenalin, noradrenalin or related substances; in particular referring to sympathetic nerve fibers.

2. Relating to or denoting an agent that mimics the activity of adrenalin, noradrenalin or related substances.

Compare cholinergic.

See sympathomimetic.

β-adrenergic antagonist

See β-blocker.

β-adrenergic blocking agent

See β-blocker.

adrenergic receptor

See α-adrenergic receptor, β-adrenergic receptor.

α-adrenergic receptor

Class of adrenergicreceptor mainly functioning in vasoconstriction and modulation of glandular secretions.

β-adrenergic receptor

adrenergic receptor

adrenoceptor

β-receptor

Member of a class of G protein-coupled receptors that are targets of the catecholamines, especially adrenalin, noradrenalin, and related substances.

β-adrenergic receptor antagonist

See β-blocker

adrenoceptor

See β-adrenergic receptor.

β-adrenoreceptor antagonist

See β-blocker

afferent

Inflowing. Of nerves, those that conduct impulses toward the central nervous system.

Antonym efferent.

agnosia

Impaired ability to recognize or comprehend the meaning of various sensations, not attributable to faulty sensory input or general intellect.

After [5]

agonist (in toxicology)

Substance that binds to cell receptors normally responding to a naturally occurring substance and produces an effect similar to that of the natural substance.

[1]

Compare antagonist.

alpha-synuclein

Protein abundant in the human brain, thought to regulate the release of dopamine.

Alzheimer disease

Common and progressive neurodegenerative disease leading to loss of memory, orientation, and judgment.

γ-aminobutyric acid (GABA)

4-aminobutanoic acid

Major neurotransmitter at inhibitory synapses in the central nervous system of mammals.

γ-aminobutyric acid (GABA) receptor

Transmembrane receptor protein that binds and responds to the inhibitory neurotransmitterγ-amino butyric acid.

GABA-A receptors are ion channels.

GABA-B receptors are G-protein-coupled signal transducers.

2-amino-3-(3-hydroxy-5-methyl-1,2-oxazol-4-yl)propanoic acid (AMPA) receptor

Glutamate receptor in the central nervous system activated by the synthetic glutamate analog, AMPA.

See also excitotoxicity.

amnesia

Partial or total, transient or permanent loss of memory.

amnesic shellfish poisoning (ASP)

Human illness caused by consumption of the marine toxindomoic acid that may lead to dizziness, confusion, motor weakness and seizures, with permanent cognitive impairment and short term memory loss.

Modified from [1]

AMPA receptor

See 2-amino-3-(3-hydroxy-5-methyl-1,2-oxazol-4-yl)propanoic acid (AMPA) receptor.

amygdala

Brain nucleus located in the median temporal lobe that is part of the limbic system and plays an important role in emotional responses.

β-amyloid

amyloid

Extracellular aggregate of misfolded fibrous proteins, typically with cross-linked β-sheet structure.

See also amyloid plaque.

amyloid plaque

neuritic plaque

senile plaque

Structure representing extracellular deposition of β-amyloid protein in the gray matter of the brain that occurs with aging and in increased amount in Alzheimer disease.

amyotrophic lateral sclerosis (ALS)

Lou Gehrig’s disease

motor neuron disease

Debilitating degenerative disease of the motor neurons characterized by progressive muscle weakness, muscle atrophy and fasciculations, muscle spasticity, difficulty speaking (dysarthria), difficulty swallowing (dysphagia), and difficulty breathing (dyspnea).

analgesic

anodyne

painkiller

Substance that relieves pain without causing loss of consciousness.

anaphrodisiac

Anything tending to reduce libido.

anesthetic

anaesthetic

Substance that reduces the experience of pain with or without loss of consciousness.

aneurysm

Abnormal bulging of the wall of an artery or a chamber of the heart.

angiography

Radiography of blood or lymph vessels, following the introduction of a radio-opaque substance.

angiospasm

See vasospasm.

annulus (of intervertebral disc)

Tough outer ring of an intervertebral disc.

anodyne

See analgesic.

anorexia

Eating disorder characterized by self-imposed food restriction.

Compare anorexia nervosa.

anorexia nervosa

Eating disorder characterized by obsessive desire to lose weight by reducing food intake or by repeated vomiting.

Compare anorexia.

anosmi/a n., /c adj.

Loss of the sense of smell, either total or selective.

anoxia

Absence of inspired dioxygen in blood or tissues; to be distinguished from hypoxia.

After [5]

antagonist (in toxicology)

Antonym: agonist

Substance that binds to a cell receptor normally responding to a naturally occurring substance and prevents a response to the natural substance.

[1]

anticonvulsant

Substance used to prevent or reduce the severity of convulsions.

antidepressant

Substance used to alleviate depression.

antiemetic

Substance used to prevent nausea and vomiting (emesis).

antineuralgic

Substance used to alleviate the pain of neuralgia.

antinociception

Blockage of the perception of pain.

See also nociception.

antipsychotic

Psychoactive substance used to manage psychotic behavior or psychotic ideation.

antispasmodic

Substance used to prevent muscle spasms.

antrum

Cavity or chamber, often one with bony walls, and with specific meaning in some hollow organs (e.g., the pyloric end or gastric antrum of the stomach).

anxiolytic

Agent that reduces anxiety without causing excessive sedation (see sedative).

Compare sedative.

aphasia

Difficulty with, or loss of the use of language in reading, writing or speaking owing to specific lesions in the brain.

Compare aphonia. See also dysphasia.

aphonia

Loss of the voice.

aphrodisiac

Anything that stimulates libido.

apneusis

apneustic respiration

Abnormal breathing pattern consisting of a pause at full inspiration.

After [5]

apneustic breathing

See apneusis

apraxia

Neurological condition characterized by loss of the ability to perform skilled or purposeful movement that a person is nevertheless physically able and willing to do.

arachnoid mater

See arachnoid membrane.

arachnoid membrane

arachnoid mater

Middle layer of the meninges (see meninx), that is, the membranes that cover the brain and spinal cord.

arachnoiditis

Inflammation of the arachnoid membrane, often characterized by perception of burning pain in the legs.

arborization

Terminal branching of a neuron into a treelike structure of the dendrites.

arrhythmia

Condition in which there is an irregular or abnormal heart beat.

arteriography

See angiography.

arteriolovenular anastomosis

Communication in which blood is shunted from arterioles to venules without passing through capillaries.

See Note to arteriovenous anastomosis.

arteriovenous (AV)

Relating to both arteries and veins.

arteriovenous anastomosis

Communication between an artery and a vein by collateral channels.

After [5]

arteriovenous fistula

Abnormal communication between an artery and a vein.

arteriovenous malformation (AVM)

Web of blood vessels with one or more abnormal communications between arteries and veins that bypass the capillary system.

associative avoidance test

Avoidance test in which the test animal has learned to develop an association between the stimulus and the delivery of an aversive event.

associative learning

Process in which a new behavior arises as a consequence of association with a particular stimulus, sometimes restricted to learning through classical conditioning.

astrocyte

Glial cell of ectodermal origin in the central nervous system, characterized by fialmentous protoplasmic extensions.

astrocyte, reactive

Astrocyte that, after injury or excessive neural activity, undergoes morphological (including extension of pseudopodia) and biochemical (notably increased synthesis of glial fibrillary acidic protein) changes and participates in astrocytic scar formation.

astrocytic scar

glial scar

Clustering of reactive astrocytes separating a localized brain injury from surrounding uninjured tissue.

astrocytoma

Tumor within the substance of the brain or spinal cord made up of astrocytes.

astrogliosis

Localized site of reactive astrocytes, distinct from an astrocytic scar.

See astrocyte, reactive.

ataxia

Loss of muscular coordination (see motor coordination) resulting in abnormal clumsiness.

athetosis

Condition in which inappropriate muscle contraction causes involuntary writhing movements.

aton/y n., /ic adj.

Lacking muscular tone.

atrophy

Pathological decrease in tissue, organ or body mass.

attention deficit hyperactivity disorder (ADHD)

hyperkinetic disorder

Neuropsychiatric disorder of childhood characterized by decreased attention span, impulsiveness and hyperactivity.

aura

Constellation of symptoms experienced before a migraine headache or seizure.

autism

Neurodevelopmental disorder, present from early childhood, characterized by great difficulty in communicating and forming relationships with other people and in using abstract concepts.

After [6]

autonomic nervous system (ANS)

Part of the peripheralnervous system controlling the bodily functions that are not consciously directed, e.g., breathing, heart rate, and digestive processes.

avoidance test

Associative learning pairing an adverse event with a non-specific stimulus such that the animal learns to respond in a manner to avoid the adverse event.

axon n., /al adj.

Long thread-like process of a neuron along which impulses are conducted from the cell body to the nerve ending.

Compare dendrite.

axonal degeneration

Progressive loss of structure and function of an axon, typically in a peripheral-to-central direction.

axonal transport

axoplasmic transport

Movement of organelles and biomolecules to (retrograde) and from (anterograde) a neuron’s cell body, within the cytoplasm of its axon (the axoplasm).

axonopathy

Damage (peripheral neuropathy) to multiple nerves in roughly the same areas on both sides of the body, causing weakness, numbness, and paresthesia.

See also polyneuropathy.

bar test

Test for catalepsy in which a mouse is placed on a bar oriented parallel to and approximately 2.5 cm off the ground. Typically, if the mouse remains immobile on the bar for more than 20 seconds, it is considered to be cataleptic.

See also tetrad test.

Barnes maze

Circular platform equipped with some 20 equidistant holes near the outer rim, one of which is marked by visual cues and is an escape hole for a rodent that is placed near the middle of the platform and subjected to an adverse stimulus, e.g., bright light.

See also maze.

basal ganglia

basal nuclei

Complex structure at the base of the brain consisting of several groups of neurons, the caudate nucleus, the putamen, the globus pallidus, and the substantia nigra).

Bayley scale

Bayley scales of infant development (BSID)

Range of scores on play tasks performed by infants age 0–3 years, intended to assess development of motor, cognitive, and language skills against norms for age-matched normal child development.

beading (in neurites)

neuritic beading

Focal bead-like swellings in dendrites and axons.

beam walking test

Assessment of the ability of an animal to remain upright and to walk on an elevated and relatively narrow beam.

Benton test

Benton visual memory test

Procedure in which patterns on cards are memorized by a test subject who then attempts to recognize them on other cards presented subsequently.

See also neurobehavior core test battery.

Biel water maze

A water labyrinth, described by Biel (1940), where rodents are forced to swim until they find a small underwater platform that allows them to escape.

See also maze.

bipolar disorder

manic-depressive disorder

Psychiatric illness characterized by mood shifts with periods of severe depressive illness and one or more episodes of exaggerated activity levels (manic behavior).

β-blocker

β-adrenergic antagonist

β-adrenergic blocking agent

β-adrenergic receptor antagonist

β-adrenoreceptor antagonist

β-antagonist

Any of a class of drugs that targets the β-adrenergic receptor, interferes with binding of adrenalin and other related substances to the receptor, and weakens their effects.

blood–brain barrier

Selectively permeable structure that restricts the exit of blood cells and many substances from the brain capillaries into the extracellular space of the brain.

blood–cerebrospinal fluid barrier

Functional restriction by cells of the choroid plexus of transit of substances from the cerebrospinal fluid into the extracellular space of the brain.

blood–retinal barrier

Functional restriction of transit of substances from the blood to the retina by non-fenestrated endothelial cells with tight junctions.

Boston naming test (BNT)

Procedure in which 60 pictures are shown to a subject who has to name them quickly.

brachial plexus

Bundle of nerve fibers that begins in the spine at the base of the neck, travels through the axilla (armpit region), and into the arm.

bradycardia

Abnormally slow heart rate.

bradykinesia

hypokinesia

Abnormally slow body movement.

brain

That part of the central nervous system contained within the cranium.

[5]

brain-derived neurotrophic factor (BDNF)

Protein secreted by the brain that acts on neurons in the central and peripheral nervous systems; a member of the neurotrophin family of growth factors, related to the nerve growth factor (NGF).

brain herniation

Movement of part of the brain across structures within the skull such as a shift across such structures as the falx cerebri, the tentorium cerebelli, and even sometimes through the foramen magnum in the base of the skull (through which the spinal cord connects with the brain).

brain slice

Slice of brain tissue immersed in artificial cerebrospinal fluid, used in electrophysiology experiments to allow study of a synapse or neural circuit in isolation from the rest of the brain, and in metabolic studies, under controlled physiological conditions.

brainstem

Unpaired subdivision of the brain, continuous with the spinal cord, that includes the thalamus, hypothalamus, pons, medulla oblongata, and the mesencephalon.

Broca area

Broca speech area

Region in the frontal lobe of one of the hemispheres (the speech-dominant hemisphere, usually the left) of the hominid brain that is involved in motor functions of speech production.

bruxism

Involuntary habitual grinding of the teeth, frequently during sleep.

burr hole surgery

trepanning

trephination

trephining

Medical intervention in which a hole is drilled or scraped into the human skull, exposing the dura mater, to gain access during surgery, to relieve intracranial pressure, to evacuate a subdural hematoma, etc.

butyrylcholinesterase

plasma cholinesterase

pseudocholinesterase

Enzyme, found mainly in the liver, that hydrolyzes choline esters; it is non-specific and distinct from acetylcholinesterase.

CA1-pyramidal cell

Pyramidal neuron located in the cornu ammonis area 1, in the hippocampus.

CA3-pyramidal cell

Pyramidal neuron located in the cornu ammonis area 3, in the hippocampus.

Caenorhabditis elegans

Nematode with a well defined small neural network and homologues of human neurotransmitters, used as a model organism for studying normal development as well as neurotoxicity.

California verbal learning test

Procedure in which some common words are read aloud and the test subject is asked to recall as many of these as possible.

carcinoma

Malignant tumor of an epithelial cell.

[1]

carotid artery

One of two paired large arteries on either side of the neck that supplies most of the cerebralhemisphere.

carpel tunnel syndrome (CTS)

Median nerve entrapment neuropathy that causes paresthesia, pain, and numbness due to compression of the nerve at the wrist in the carpal tunnel.

cassava toxin

See cassavism.

cassavism

konzo

mantakassa

Epidemic paralytic disease, mainly affecting women and children, occurring in remote rural areas of African and Latin American countries, where cassava root is an important food.

cauda equina

Bundle of long spinal nerve roots arising from the end of the spinal cord and filling the lower part of the spinal canal (from approximately the thoraco-lumbar junction downwards).

caudate nucleus

caudatum

Crescent-shaped mass of gray matter forming part of the corpus striatum and part of the basal ganglia.

central nervous system (CNS)

Part of an animal’s nervous system that exerts control over the rest of the nervous system; in vertebrates, the brain and spinal cord protected within the dorsal cavity (cranial and spinal cavities).

cephalic

In or relating to the head.

ceramide

Family of lipid molecules, each one composed of sphingosine and a fatty acid.

cerebellar tonsillar herniation

Abnormal protrusion of a portion of the cerebellum through the foramen magnum of the skull.

cerebellum

Lower part of the brain that is beneath the posterior portion of the cerebrum, regulating the unconscious coordination of movement.

See also inferior cerebellar peduncle.

cerebral cortex

Outer layer of the cerebrum, composed of folded gray matter, playing an important role in consciousness.

cerebral herniation

See brain herniation.

cerebroside

Member of a group of glycosphingolipids called monoglycosylceramides which are important components in animal nerve and muscle cell membranes and the myelin sheath.

cerebrospinal fluid (CSF)

Clear colorless extracellular fluid found in the brain and spinal cord filling the ventricles and subarachnoid spaces.

cerebr/um n., /al adj.

Principal part of the brain in vertebrates, located frontwards in the skull, consisting of the two hemispheres of the cerebral cortex separated by a fissure, and certain subcortical structures such as the hippocampus, basal ganglia, and the olfactory bulb.

cervical spine (in vertebrates)

Part of the spine immediately inferior to the skull and connecting to the thoracic spine, made up of seven vertebrae.

cervical vertebra

Any of seven vertebrae that provide strength and structure to the cervical spine and support the head, allowing for its rotation and flexion.

cholinergic

1. Relating to or denoting a nerve that liberates acetylcholine at a synapse upon receiving an appropriate nerve impulse; in particular referring to parasympathetic nerve fibers.

2. Relating to or denoting an agent that mimics or enhances the activity of acetylcholine.

Compare adrenergic.

cholinesterase

See acetylcholinesterase, butyrylcholinesterase.

cholinesterase inhibitor

See acetylcholinesterase inhibitor.

cholinomimetic

Having an action similar to acetylcholine.

See also parasympathomimetic.

chorea

choreia

Neurological disorder characterized by rapid, jerky involuntary movements affecting especially the limbs or facial muscles.

choreoathetosis

Occurrence of involuntary movements in a combination of chorea and athetosis.

choroid plexus

Branching network of blood vessels in the cerebralventricles that serves to regulate intraventricular pressure by secretion or absorption of cerebrospinal fluid.

chromatolysis

1. Disintegration of nuclear chromatin.

2. Disintegration of Nissl bodies following neuronal injury.

chronic solvent-induced encephalopathy (CSE)

organic solvent syndrome

toxic solvent syndrome

Constellation of neurological symptoms that may include polyneuropathies, encephalopathy, memory loss, attention deficit and dementia following long-term exposure, often occupational, to organic solvents found in paints, glues, and other industrial products.

ciguatera poisoning

Food-borne illness caused by ingesting fish containing ciguatera toxins.

ciliary muscle

Intrinsic smooth muscle of the eye that contracts to cause the lens to thicken, allowing accommodation to near vision.

ciliary neurotrophic factor

Polypeptide hormone and nerve growth factor that promotes neurotransmitter synthesis and neurite outgrowth in certain neural populations including astrocytes.

clon/us n., /ic adj.

1. Alternate involuntary muscular contraction and relaxation in rapid succession.

2. Continuous rhythmic reflex tremor initiated by the spinal cord below an area of spinal cord injury, set in motion by reflex testing.

[7]

cognit/ion n., /ive adj.

Sum of the mental processes by which sensory input is stored, recovered, and used by the consciousbrain, including attention, memory, language usage, learning, reasoning, problem solving, and decision making.

cognitive function

See cognition.

coma

State of profound unconsciousness lasting more than several hours in which one cannot respond to stimuli and from which one cannot be roused.

computed tomography (CT)

X-ray computed tomography (X-ray CT)

computerized axial tomography (CAT)

Tomographic technique that rapidly images the body in cross-sections, or slices: thereafter, a computer algorithm reconstructs a map from the slices to create a three-dimensional image of soft tissue or bone.

conditioned avoidance response (CAR) test

Experimental procedure in which an adverse effect (e.g., foot shock, drug withdrawal) is delivered to rats or mice after presentation of a cue (e.g., light or sound); the rodents are trained to avoid rather than escape the shock after the start of its delivery.

conditioning, classical

Pavlovian conditioning

respondent conditioning

Learning in which a behavior comes to be elicited as a reflex response by association with a neutral antecedent stimulus through repetition of the stimulus-response pairing.

conditioning, operant

instrumental conditioning

Learning in which appropriate behavior is rewarded, or inappropriate behavior is punished; behavior is modified by learned association with antecedents and consequences.

See also reinforcement.

cone cell

See photoreceptor cell.

confusion

Mental state of bewilderment or disorientation in which reactions to environmental stimuli may be inappropriate.

conscious adj., /ness n.

Aware of and responding to one’s surroundings.

continuous performance test (CPT)

Any of several available neuropsychological procedures that measure a person’s sustained attention.

contracture

contraction

Persistent shortening and tightening of muscle, tendon, or other tissue.

contrast medium

Any material (usually opaque to X-rays) employed to delineate or define a structure during a radiologic procedure.

convulsion

Sudden, violent, irregular movement of the body, caused by involuntary contraction of muscles and associated with brain disorders such as epilepsy, fever in children, or drug or alcohol abuse.

cornu ammonis

Part of the hippocampus.

coronal

Vertical (longitudinal) plane dividing the body into ventral and dorsal (front and back) sections.

coronal suture

Transverse junction in the skull separating the frontal bone from the parietal bones.

corpus callosum

Bundle of myelin-enriched neural fibers beneath the cortex connecting the two hemispheres of the brain.

corpus striatum

Striatum together with the globus pallidus.

cramp

Painful muscle spasm caused by prolonged tetanic contraction.

After [5]

cranial nerve

Each of 12 pairs of nerves that arise directly from the brain, not from the spinal cord, and pass through separate apertures in the skull.

cranial suture

Line where the bony plates of the skull join together, consisting of fibrous bands of tissue, easily felt in the newborn until closure by ossification.

craniopharyngioma

Congenital tumor arising from the pituitary gland in the embryonic tissue between the brain and pharynx.

crani/um n., /al adj.

Boney structure surrounding the brain, excluding the bones of the face.

cranium bifidum

See encephalocele.

Cre/loxP

Bacterial system in which the Cre protein mediates DNA recombination between specific DNA sequences known as lox-P sites.

cue

Stimulus or associated feature of a stimulus that evokes a response or alerts the subject to a particular behavior.

cycad toxin

See Western Pacific amyotrophic lateral sclerosis and parkinsonism–dementia complex.

delirium

State of severe confusion, characterized by restlessness, hallucinations and hyperactivity, during which the person affected may be isolated from normal communication.

dementia

Serious loss of brain function in a previously unimpaired person, affecting memory, thinking, and behavior.

dementia, presenile

Dementia, often of the Alzheimer type (see Alzheimer disease) developing at or before age 65.

After [5]

dementia, senile

Dementia, often of the Alzheimer type (see Alzheimer disease) developing after the age of 65.

After [5]

demyelination

demyelinization

Destruction of the protective myelin sheath that surrounds nerve fibers, resulting in diminished function and decreased action potential in those nerves.

dendrite

Short branched extension of a nerve cell, along which impulses received from other cells at synapses are transmitted to the cell body.

Compare axon.

dentate gyrus

Narrow strip of cerebral cortex associated with the hippocampus that continues forward to the uncus.

dependence, physical

See addiction.

dependence, psychological

See addiction.

dependency, chemical

drug addiction

Craving for or addiction to a substance.

depolarization

Relative reduction in the resting membrane potential of an excitable cell, generally making the inside less negative, or even positive with respect to the outside.

depression (of the central nervous system)

1. Reduction in the activity of the central nervous system.

2. Mental state or disorder characterized by feelings of sadness and despair.

After [5]

despair test

behavioral despair test

See swimming test, tail suspension test.

developmental neurotoxicity

Adverse effects of toxic substances on the development of the nervous system.

developmental neurotoxicity testing (DNT)

Any examination that allows detection of substance-induced changes in the structural or functional integrity of the nervous system of a developing organism, fetus or child.

diaphoretic

1. n. Substance inducing perspiration.

2. adj. Of a human, sweating heavily.

diarrheal shellfish poisoning (DSP)

diarrhetic shellfish poisoning (DSP)

Serious illness characterized primarily by diarrhea with rapid onset and resolution after 24 h that is a consequence of consumption of bivalve shellfish (mollusks) such as mussels, oysters, and clams that have ingested, by filter feeding, large quantities of dinoflagellates containing a group of high-molecular-weight structures with multiple ether linkages, such as okadaic acid ((2R)-3-[(2S,6R,8S,11R)-2-[(E,1R)-3-[(2S,2&primeR,4R,4aS,6R,8aR)-4-hydroxy-2-[(1S,3S)-1-hydroxy-3-[(2S,3R,6S)-3-methyl-1,7-dioxaspiro[5.5]undecan-2-yl]butyl]-3-methylene-spiro[4a,7,8,8a-tetrahydro-4H-pyrano[2,3-e]pyran-6,5′-tetrahydrofuran]-2′-yl]-1-methyl-prop-2-enyl]-11-hydroxy-4-methyl-1,7-dioxaspiro[5.5]undec-4-en-8-yl]-2-hydroxy-2-methyl-propanoic acid), dinophysis toxins, pectenotoxins, and yessotoxin (2-[(2S,4aS,5aR,6R,6aS,7aR,8S,10aS,11aR, 13aS,14aR,15aS,16aR,18S,19R,20aS,21aR,22aS,23aR,24aS,25aR,26aS,27aR,28aS,29aR)-6-Hydroxy-2-[(2R,3E)-2-hydroxy-5-methylene-3,7-octadien-2-yl]-5a,8,10a,11a,19-pentamethyl-3-methylene-18-(sulfooxy)octatriacontahydropyrano[2″′,3″′:5″,6″]pyrano[2″,3″:5′,6′]pyrano[2′,3′:5,6]pyrano[3,2-b]pyrano[2″″′,3″″′:5″″,6″″]pyrano[2″″,3″″:5″′,6″′]pyrano[2″′,3″′:5″,6″]pyrano[2″,3″:6′,7′]oxepino[2′,3′:5,6]pyrano[2,3-g]oxocin-19-yl]ethyl hydrogen sulfate).

After [1]

diencephalon

Posterior part of the forebrain (prosencephalon), containing the hypothalamus and other thalamic components, and enclosing the third ventricle.

differentiation (in biology)

Process by which a cell is committed to a lineage and becomes more specialized in structure and function.

digit span test

digit span task

Test of memory in which numbers (series of digits) are presented orally or on a computer screen to a test subject who is asked to repeat each number from memory; the numbers increase in length until mistakes are made.

See also neurobehavior core test battery.

digit symbol substitution test (DSST)

digit symbol test

Neuropsychological assessment in which the top two rows of a test sheet function as a key, displaying numbers 1–9 (upper row) matched to “non-sense” symbols (lower row). There follow pairs of rows where the numbers 1–9 appear in irregular sequence and the test subject must match the correct symbol from the key to each number, as quickly as possible.

See intelligence quotient.

See also neurobehavior core test battery.

diplopia

double vision

Simultaneous perception of two images of a single object.

disc, intervertebral

spinal disc

Flat circular structure, consisting of a tough, fibrous exterior and a gelatinous core, interposed between adjacent vertebrae.

disorientation

1. Loss of sense of direction.

2. In clinical assessment, lack of awareness of one’s identity, present location, or the current day and time.

domoic acid

(2S,3S,4S)-4-[(2Z,4E,6R)-6-carboxy-6-methylhexa-2,4-dien-2-yl]-3-(carboxymethyl)pyrrolidine-2-carboxylic acid

Neurotoxic kainic acid analog produced by some algal blooms that causes amnesic shellfish poisoning.

dopamine

4-(2-aminoethyl)benzene-1,2-diol

Naturally occurring substance functioning as a neurotransmitter in the sympathetic nervous system, and a metabolic precursor of other substances including adrenalin.

dopaminergic

Relating to a nerve that releases or responds to dopamine as a neurotransmitter.

dorsal root

posterior root of spinal nerve

Outgrowth of a spinal nerve that carries sensory signals to an appropriate integration center in the brain.

dorsal root ganglion

Nodule on a dorsal root of the spine that consists of afferent sensory neuronal cell bodies.

See also ganglion.

dura mater

Outermost and most fibrous of the three membranes of the meninges (see meninx) covering the brain and the spinal cord.

dynein

Protein associated with motile structures that exhibits adenosine triphosphatase activity; it forms “arms” on the outer microtubules of cilia and flagella and functions as a molecular motor.

dynorphin

Member of a class of opioid peptides that arise from the precursor protein prodynorphin.

dysaphia

Impairment of the sense of touch.

dysarthria

Difficulty in speech owing to disturbances of muscular control resulting from central or peripheral nervous system damage or emotional stress.

dysesthesia

1. Condition in which a disagreeable sensation, especially of touch, is produced following damage to peripheral or central sensory pathways.

2. Abnormal sensation experienced in the absence of stimulation.

[5]

dysgraphia

Difficulty in writing.

dyskinesia

Difficulty or abnormality in voluntary movement.

dyskinesia, tardive

Involuntary, repetitive body movement of slow onset.

dyslexia

Impairment in appreciation of spatial relations, often leading to difficulty in reading.

dysphagia

Difficulty in swallowing.

dysphasia

Difficulty in the use of language owing to a brain lesion, without mental impairment.

See also aphasia.

dyspnea

Difficulty in breathing; shortness of breath.

dysreflexia, autonomic (AD)

Over-activity of the autonomic nervous system causing an abrupt onset of excessively high blood pressure, tachycardia, and constriction of peripheral blood vessels.

Compare hyperreflexia.

dystonia

State of abnormal (either hypo- or hypertonic) muscle tone resulting in impairment of voluntary movement.

After [5]

edema

oedema

dropsy

Presence of abnormally large amounts of fluid in intercellular spaces of body tissues.

[1]

efferent

Carrying outward; of nerves, those that conduct impulses outward from the central nervous system.

Antonym afferent.

electroconvulsive therapy (ECT)

electroshock therapy

Therapeutic intervention in which seizures are electrically induced in patients with the aim of providing relief from a specific mental illness.

electroencephalogram

Test or record of brain electrical activity detected by electroencephalography.

electroencephalography (EEG)

Recording of electrical activity from different parts of the brain.

electromyography (EMG)

Recording of the electrical activity of muscle, or its representation as a visual display or audible signal, using electrodes attached to the skin or inserted into a muscle.

electroneurography

Non-invasive method used to examine the integrity and conductivity of a peripheral nerve, in which a brief electrical stimulation is given to the nerve at one point, while at the same time the induced electrical activity (compound action potentials) is recorded at another point of the nerve’s distribution and the interval is displayed on a video monitor.

electrophysiology

Study of the electrical properties of cells and tissues.

electroretinogram (ERG)

Recording, with electrodes placed on the cornea or nearby skin, of the electrical activity of photoreceptors and other retinal cells in response to standardized, patterned stimuli with light and colour.

elevated plus maze

Stage with four orthogonal side arms elevated above the floor, where two opposite arms have sidewalls and the other two arms have no walls; used as research tool for anxiety.

emesis

Vomiting.

emetic

1. n. Substance that produces vomiting.

2. adj. Producing vomiting.

encephalitis

Inflammation of the brain.

encephalopathy

Any disorder of the brain that affects its functioning.

endocrine disruptor

endocrine modifier

Exogenous chemical that alters function(s) of the endocrine system and consequently causes adverse health effects in an intact organism, its progeny, or (sub)populations.

[1]

endorphin

One of several peptides (including the enkephalins) that activates the body’s opiate receptors, causing an analgesic effect; literally, endogenous morphine-like substance.

See also enkephalin.

enkephalin

Either of two endogenous pentapeptides with opiate-like effects that are especially involved in modulating pain responses in the central nervous system.

See also endorphin.

ependymal tissue

Glial cells that line the cavities within the brain’s ventricles.

ependymoma

Growth in the brain or spinal cord arising from ependymal tissue.

epidural

extradural

Immediately outside the dura mater.

epilepsy

Chronic neurological disorder marked by sudden recurrent episodes of sensory disturbance, loss of consciousness, or convulsions, associated with abnormal electrical activity in the brain.

epinephrine

See adrenalin.

epithalamus

Dorsal part of the diencephalon, including the pineal gland and adjacent structures in the roof of the third ventricle.

ergotism

St Anthony’s fire

ignis infernalis

ignis sacer

Poisoning produced by eating food affected by ergot (ergotamine alkaloids), substances produced by the fungus Claviceps purpurea that contaminate rye and wheat.

euphori/a n. /c adj.

Characterized by or feeling intense excitement and happiness.

evoked potential

Electrical potential that is triggered by presentation of a stimulus (somatosensory, auditory, visual) and measured with electrodes near the nerve or near the brain region in which the signal is processed.

evoked response

evoked potential

Electrical potential recorded from the nervous system following exposure to a stimulus, as distinct from spontaneous potentials detected by electroencephalography, electromyography, or other electrophysiological recording methods.

excitable cell

Cell that can be stimulated to create an electric current; muscle fibers and nerve cells are excitable (see excitation).

excitation

State of enhanced activity of a cell, organism, or tissue that results from stimulation.

See also excitable cell.

excitatory post-synaptic potential (EPSP)

Referring to a more positive membrane potential at the postsynaptic side of the synaptic cleft that renders the postsynaptic neuron more likely to generate an action potential.

excitotoxicity

Pathological process by which neurons are damaged and killed by the overactivation of receptors for the excitatory neurotransmitterglutamate, such as the N-methyl-d-aspartic acid (NMDA) receptor and the 2-amino-3-(3-hydroxy-5-methyl-1,2-oxazol-4-yl)propanoic acid(AMPA) receptor.

extrapyramidal system

See motor system.

facilitation

1. Neural facilitation: Increase in postsynapticexcitation as a result of very rapid firing of action potentials by a presynapticneuron.

2. Presynaptic facilitation: Increase of prepsynaptic excitation when an excited neuron receives additional excitatory impulses from other neurons.

falx (cerebri)

Continuation of dura mater between the right and left hemispheres of the brain.

Farnsworth dichotomous test

See Lanthony D-15 color test.

fasciculation

Involuntary contractions, or twitchings, of groups (fasciculi) of muscle fibers

After [5]

fatigue

Mental state characterized by weakness, sleepiness and reduced performance, often a consequence of physical exhaustion, disease, or chemotherapy.

fetal alcohol syndrome

Condition developing in the fetus and resulting in a congenital abnormality, caused by excessive alcohol intake by the mother during pregnancy, typically characterized by delayed cognitive development, stunted growth and a characteristic facies.

fibrillation

Rapid contractions or twitching of muscle fibrils, but not of the muscle as a whole.

Compare fasciculation.

finger tapping test

Procedure in which a test subject is asked to tap a finger at maximal rate on a surface, a higher rate of tapping indicating better neuromuscular function.

flaccid

Relaxed, flabby, or without tone.

[5]

foramen

Opening, hole.

foramen magnum

Large foramen in the base of the skull, through which the spinal cord passes.

foramen ovale

1. One of the larger foramina in the base of the skull.

2. In the fetal heart, opening that allows shunting of blood between the right and left atria that should close at birth.

forebrain

See prosencephalon.

frontal lobe

Most anterior of the four major lobes of each cerebral hemisphere, containing the primary motor cortex.

frontotemporal dementia (FTD)

frontotemporal lobular degeneration (FTLD)

Neurodegenerative disease characterized by progressive neuronal defects in the frontal and temporal lobes of the brain, leading to dementia

functional domain

In the brain, referring to the concept that discrete regions are involved in specific aspects of cognitive function, thus giving rise to modularity.

functional observational battery

Structured set of tests to examine changes in neuromuscular, arousal, autonomic and sensory functions that assesses the presence, absence or severity of specific neurological signs.

FUS (fused in sarcoma) transcription factor

Nuclear DNA- and RNA-binding protein involved in transcription, splicing, and RNA-transport.

GABA

See γ-aminobutyric acid.

GABA receptor

See γ-amino butyric acid receptor.

GABAergic

Pertaining to the action of γ-aminobutyric acid or to neural or metabolic pathways in which it functions as a neurotransmitter.

[5]

ganglion

1. Cluster of nerve cell bodies located outside the brain and spinal cord, i.e., in the peripheral nervous system

   Note:

   Ganglia interconnect to form a complex network known as a plexus and serve as relay stations where different neurons can modulate the signals of each other.

   Compare basal ganglion.

2. Fibrous cyst usually attached to a tendon sheath.

ganglion cell

Neuron located in a ganglion.

ganglioside

Glycosphingolipid chemically similar to cerebrosides but containing one or more sialic (N-acetylneuraminic or N-glycolylneuraminic) acid residues, found principally in nerve tissue, spleen, and thymus.

After [5]

giant axon

squid giant axon

Very large axon (typically 0.5 mm in diameter) that functions in the propulsion system of the squid.

giant axonal neuropathy

Rare human genetic neurological disorder in which the neurofilaments become disordered, resulting in abnormal size and shape of neurons.

glia n., /l adj.

neuroglia

Non-neuronal cellular elements of the central and peripheral nervous system having metabolic and support functions.

glial cell

Cellular component of the glia, including oligodendroglial cells, astrocytes, ependymal cells and microglial cells.

glial-derived neurotrophic factor (GDNF)

Protein that promotes and guides the growth of neurons and facilitates the survival of mature neurons by suppressing cell death.

glial fibrillary acidic protein (GFAP)

Cytoskeletal intermediate filament protein found in mature fibrillary astrocytes and in neural progenitor cells.

After [5]

glioblastoma

glioblastoma multiforme

Glioma consisting chiefly of undifferentiated anaplastic cells of astrocytic origin.

After [5]

glioma

Neoplasm originating from any of the glia cells in the brain and spinal cord.

gliosis, reactive

Damage-induced proliferation, enlargement and overgrowth of glial cells, often astrocytes in the central nervous system, resulting in an astrocytic scar.

globoside

Glycosphingolipid, specifically a ceramide tetrasaccharide (tetraglycosylceramide), isolated from kidney and erythrocytes.

After [5]

glutamate

Salt of glutamic acid (2-aminopentanedioic acid).

glutamate-induced excitotoxicity

Form of excitotoxicity where excess glutamate release in synapses (glutamatergic storm) leads to overstimulation, followed by excess cellular calcium uptake, cytotoxicity and apoptosis.

glutamatergic storm

See glutamate-induced excitotoxicity.

glycosphingolipid

Any representative of a group of glycolipids where a carbohydrate is connected with sphingosine (see also sphingolipid).

Golgi staining

Golgi’s method

Method of silver staining of histological sections of tissue from the nervous system, in which a limited number of neurons stain in their entirety upon formation of microcrystals of silver chromate, thus allowing visualization in the light microscope of some individual neurons in densely packed tissue.

G-protein-coupled receptor (GPCR)

Seven-transmembrane-domain receptor that interacts with guanosine triphosphate/diphosphate (GTP/GDP) binding proteins to initiate signal transduction.

granule cell

One of several types of neurons with small cell bodies, involved in neural networks in several regions of the brain, including the cerebellum, hippocampus, and cerebral cortex.

grass pea poisoning

See lathyrism.

gray matter

Regions of the brain and spinal cord that are made up primarily of the cell bodies and dendrites of nerve cells rather than of myelinated axons.

After [5]

Compare white matter.

Guillain-Barré syndrome (GBS)

Type of idiopathic polyneuritis in which autoimmunity to peripheral nerve myelin leads to a condition characterized by chronic demyelination of the spinal roots (see spinal cord), peripheral nerves, and cranial nerves.

After [3]

habituation

Decrease or cessation of a response to a stimulus after its repeated presentation.

hallucinat/ion n., /e vb.

The apparent, often strong, subjective perception of an external object or event when no such stimulus or situation is present.

[5]

headache

Pain in one or more parts of the cranium, not confined to the area of distribution of any nerve.

After [5]

headache, rebound

Headache caused by stopping analgesics following their overuse to relieve headaches.

headache, tension

Headache associated with anxiety or other states of distress, associated with chronic contraction of the scalp muscles.

After [5]

hemangioma

Vascular malformation present at birth or developing during life, in which proliferation of blood vessels leads to a vascular tangle.

hematoma

Region of bleeding into a tissue or organ.

hemiplegia

Paralysis of one side of the body, including the arm, trunk and leg.

hemisphere, cerebral

Right or left half of the brain in sagittal section.

hemisphere, dominant

Cerebral hemisphere containing the representation of speech and controlling arm and leg preference in skilled movements.

After [5]

hemorrhage

Copious escape of blood from a disrupted blood vessel.

hen test

Procedure using birds to study acute and delayed neurotoxicity, notably of organophosphates.

hippocampal slice culture

Maintenance in vitro of fresh prepared slices of the hippocampus

See also brain slice.

hippocampus

Structural component of the limbic system of the vertebrate brain involved in short-term and long-term memory and spatial navigation.

See also CA pyramidal cell, dentate gyrus, granule cell.

histamine

2-(1H-imidazol-4-yl)ethanamine

Bioactive metabolite produced in living organisms by deamination of the amino acid histidine.

See also Scombroid poisoning.

histaminergic

Pertaining to the action of histamine or to neural pathways in which it functions as a neurotransmitter.

hormon/e n., /al adj.

Substance formed in one organ or part of the body and carried in the blood to another organ or part where it selectively alters functional activity.

[1]

Huntington disease

Genetic autosomal dominant neurodegenerative disease resulting from a mutation in the Huntingtin gene and resulting notably in decline of cognitive function and a characteristic chorea.

hydrocephalus

Excessive accumulation of cerebrospinal fluid in the cerebralventricles, often in the developing embryo.

hydrocephalus, communicating

Hydrocephalus where flow of cerebrospinal fluid is not blocked but there is failure of its reabsorption.

hydrocephalus, obstructive

Hydrocephalus where flow of the cerebrospinal fluid is blocked.

hydromyelia

Pathological dilation of the spinal cord due to expansion of the cerebrospinal fluid-filled central canal of the cord.

5-hydroxytryptamine (5-HT)

serotonin

3-(2-aminoethyl)-1H-indol-5-ol

Neurotransmitter found in the digestive tract, platelets and central nervous system.

hypercapnia

Abnormally increased carbon dioxide concentration in the blood resulting in a increased rate and depth of breathing.

hyperesthesia

Excessive sensitivity to touch, pain, or other sensory stimuli.

hyperpolarization

Transient increase in membrane polarization of nerve cells or muscle cells; the opposite of depolarization.

hyperreflexia

Increased or exaggerated reflex response.

hypertonia

Extreme tension of the muscles or arteries.

[5]

hypnotic

Agent that may reduce anxiety and induces sleep.

See also soporific.

hypocapnia

Abnormally decreased carbon dioxide concentration in the blood.

hypophysectomy

Surgical removal of the pituitary gland (hypophysis).

hyporeflexia

Diminished reflex response.

hypotension

1. Subnormal arterial blood pressure.

   Note:

   Hypotension can be a cause of dizziness, weakness and fainting.

2. Lower than normal pressure or tension of any kind (used less commonly).

   [5]

hypothalamus

A region at the base of the brain containing specialized nerve cells that helps activate, control, and integrate peripheral autonomic mechanisms, endocrine activities, and some somatic functions such as body temperature, sleep, and appetite.

hypotonia

1. Condition in which there is a diminution or loss of muscle tone.

2. Relaxation of the arteries.

3. Lower than normal tension in any part, as in intraocular pressure of the eyeball.

   After [5]

hypoxia

Suboptimal concentration of dioxygen in the inspired air, in the circulating blood, or in a tissue.

ictus

Sudden attack, stroke or seizure.

inclusion body

Particle in a cell, detectable under the light microscope.

inferior cerebellar peduncle

Part of the cerebellum that is important for a number of motor functions, including balance, position sensing and coordination of movement (see motor coordination).

inflammation

Reaction of the body to injury or to infectious, allergic, or chemical irritation; characterized by redness, swelling, heat, and pain resulting from dilation of the blood vessels accompanied by loss of plasma and leukocytes into the tissues.

[3]

infratentorial

Below the tentorium.

infundibulum

Neural stalk extending from the base of the brain to the pituitary gland.

inhibitory post-synaptic potential (IPSP)

Referring to a more negative membrane potential at the postsynaptic side of the synaptic cleft that renders the postsynaptic neuron less likely to generate an action potential.

insecticide

Substance intended to kill insects.

[1]

insomnia

Inability to sleep during the period when sleep should normally occur.

After [5]

intelligence quotient (IQ)

Numeric measure of a person’s cognitive function based on one of several standardized tests of a problem-solving nature.

intention tremor

See tremor.

intracranial pressure (ICP)

Pressure within the cranial cavity.

intrathecal

Within a sheath, as within either the subarachnoid or the subdural space.

After [5]

ion channel

Pore-forming transmembrane protein that can gate the transmembrane flux of small ions.

ion channelopathy

Neuromuscular disease resulting from a genetic defect in an ion channel.

ionized calcium-binding adapter molecule 1 (Iba-1)

allograft inflammatory factor 1 (AIF-1)

Protein that is expressed in several tissues, but in brain is a specific immunomarker for microglia.

ischemia

Local deficiency of blood supply and hence oxygen to an organ or tissue owing to constriction of the blood vessels or to obstruction.

IQ test

See intelligence quotient.

Irwin battery

Set of neurobehavioral tests, including observations of behavior in novel environments, of reactions, and of motor functions; used in various modifications and resembling the functional observational battery.

kainic acid

(2S,3S,4S)-3-(carboxymethyl)-4-(prop-1-en-2-yl)pyrrolidine-2-carboxylic acid

Natural amino acid produced by some seaweeds that activates a subclass of glutamate receptors (“kainate receptors”) to produce excitotoxicity.

kindling

Increase of epileptogenic (see epilepsy) activities as a result of repeated, longer-lasting subthreshold brain stimulation, e.g., with electrical stimuli.

lacrimation

Secretion and discharge of tears.

[1]

Lanthony D-15 color test

Lanthony D-15 desaturated hue panel

Test of color vision using 15 distinct color chips with low color saturation that have to be arranged in a correct order.

latent

Not yet manifest; dormant but potentially discernible.

After [5]

latent period

1. Delay between exposure to a harmful substance and the manifestations of a disease or other adverse effect.

2. Period from disease initiation to disease detection.

[1]

lathyri/sm n., /tic adj.

grass pea poisoning

Disease characterised by spasticparalysis of the legs and lower part of the body, pain, hyperesthesia, and paresthesia.

lethargy

Relatively mild impairment of consciousness resulting in reduced alertness and awareness.

levarterenol

S-noradrenaline

4-[(1S)-2-amino-1-hydroxyethyl]benzene-1,2-diol

Levorotatory isomer of norepinephrine, having greater pressor activity than the natural dextrorotatory isomer.

libido

Conscious or unconscious sexual desire; passionate interest in life force.

After [5]

ligand-gated ion channel

Ion channel that opens upon binding an activating ligand.

Compare voltage-gated ion channel.

limbic system

Collection of interconnected neurons lying underneath the cerebrum on either side of the thalamus, related more by anatomical location than as a single functional entity.

lipoma

Benign tumor of the adipose tissue, often visible under the skin.

lobe (of cerebral cortex)

One of the four main regions of the cerebral cortex.

See frontal lobe, occipital lobe, parietal lobe, temporal lobe.

lower motor neuron

Neuron that receives impulses from an upper motor neuron and whose axons innervate the skeletal muscles.

lumbar puncture

Procedure for sampling the cerebrospinal fluid through a needle positioned in the subarachnoid space of the spinal cord, between vertebrae of the lumbar spine.

lumbar spine

Portion of the vertebral column of the lower back between the thoracic spine and sacrum, in humans consisting of five vertebrae designated L1 to L5.

magnetic resonance imaging (MRI)

nuclear magnetic resonance imaging (NMRI)

magnetic resonance tomography (MRT)

Diagnostic imaging technique that produces three-dimensional images of body structures based on the ability to detect changes in nuclear spin alignment of nuclei held in a strong magnetic field and subjected to radiofrequency pulses.

magnetic resonance spectroscopy (in neurotoxicology)

Noninvasive method based on nuclear spin alignment that allows localization of levels and measurement of kinetics of an injected labeled substances in living tissue.

manganism

Condition of manganese poisoning, usually after chronic inhalation exposure to manganese fumes.

maze

Labyrinthine system, in which the ability of an animal (usually a rodent) to find a direct route from a starting point to a specific location is observed.

See also Barnes maze, Biel water maze, radial arm maze, T-maze, water maze test.

medulla

medulla oblongata

Lower part of the brain stem continuous with the spinal cord, containing neural centers regulating the autonomic functions of breathing, heart rate, and blood pressure.

medulloblastoma

Highly malignant, invasive brain tumor of embryonal origin, arising in the posterior fossa, usually from the cerebellum.

membrane polarization

Occurrence of a potential difference across a biological membrane.

membrane potential

Difference in electric potential between the inside and the outside of a cell.

See also depolarization, ion channel.

meninges

Plural of meninx.

meningioma

Firm, often vascular, tumor arising from the meninges of the brain or spinal cord.

meningitis

Inflammation or infection of the meninges.

meningocele

Protrusion of the meninges of the spinal cord through a defect in the spinal column.

meningoencephalitis

cerebromeningitis

encephalomeningitis

Inflammation of the brain and meninges.

meningoencephalocele

Protrusion of both the meninges and brain tissue through a defect in the skull.

meninx

Any membrane; specifically, usually referring to one of the membranous coverings of the brain and spinal cord.

[5]

mental retardation

Formerly used term to describe intellectual disability.

mentation

Mental activity, conscious or unconscious, but especially referring to thinking and reasoning.

mesencephalon

midbrain

Rostral part of the brainstem that contains nuclei of cranial nerves controlling shape and movement of the eye.

N -methyl-D-aspartate (NMDA).

Excitotoxic non-essential amino acid used experimentally to identify a specific subset of glutamatereceptors.

N -methyl-D-aspartate (NMDA)-type glutamate receptor

One of the various types of receptors of the neurotransmitterglutamate.

See also α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor, N-methyl-D-aspartate (NMDA).

1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)

Synthetic substance causing parkinsonism.

microglial cell

Small glial cell; resident macrophage derived as a mononuclear phagocyte that populates the brain in early development.

microgliosis

Morphological response of microglia to injury, characterized by hypertrophy and amoeboid morphology.

midbrain

See mesencephalon.

migraine

Recurrent syndrome usually characterized by unilateral head pain accompanied by symptoms including nausea and vomiting, vertigo, photophobia and other visual phenomena.

After [5]

See also aura, prodromal stage.

migrainous infarction

Stroke that occurs in connection with a migraine attack.

Minamata disease

methylmercury poisoning

Neurological disorder caused by methylmercury intoxication, characterized by tremors, dysarthria, ataxia, and loss of peripheral sensation, hearing and vision.

After [5]

Minnesota multiphasic personality inventory (MMPI)

MMPI-2-RF

Questionnaire type of psychological test for ages 18 and older. The RF version has 338 true–false statements with seven validity and ten personality scales that may be used in either an individual or group format.

miosis

Abnormal contraction of the pupil of the eye to less than 2 mm.

[1]

misfolded protein

Protein that has the same amino acid sequence as the normal, functional protein but exhibits a deviant tertiary structure and lacks normal function.

See also inclusion body.

mitochondrial membrane potential (Δψm)

Membrane potential across the inner membrane of the mitochondrion generated by the electron transport chain.

mixed neuropathy

Dysfunction or degeneration of both motor and sensory nerves.

Monro-Kellie hypothesis

Monro-Kellie doctrine

Monro doctrine

Hypothesis that the intracranial volume is unchangeable and therefore a constant intracranial pressure requires that the sum of the volumes of the three compartments blood, brain tissue and cerebrospinal fluid remains constant.

Moro reflex

See startle reflex.

morphine

(5α,6α)-7,8-didehydro-4,5-epoxy-17-methylmorphinan-3,6-diol

The major phenanthrene alkaloid of opium, used as an analgesic, sedative, and anxiolytic.

Morris water maze

See water maze test.

motor activity

Physical activity and performance of an animal.

motor coordination

Cooperation of the motor neurons and the involved muscles to perform a body movement precisely according to spatiotemporal requirements.

motor cortex

Region of the cerebral cortex, located primarily in the frontal lobe, involved in coordinating motor activity.

motor endplate

Complex structure by which the axon of a motor neuron establishes synaptic contact with a skeletal muscle fiber.

motor neuron

Nerve cell in the spinal cord having an axon that leaves the central nervous system to establish a functional connection with an effector (muscle or glandular) tissue.

After [5]

motor neuron disease (MND)

Generic term for a heterogenous group of disorders, all affecting motor neurons in the brain, spinal cord, or both.

After [5]

motor system

Part of the central nervous system responsible for control of movement, consisting of the pyramidal system controlling voluntary movement and the extrapyramidal system coordinating involuntary movement.

multiple chemical sensitivity (MCS)

environmental illness

idiopathic environmental intolerance

Intolerance condition attributed to extreme sensitivity of individuals to various environmental chemicals, found in air, food, water, building materials, or fabrics.

[1]

multiple sclerosis (MS)

Common demyelinating (see demyelination) disorder of the central nervous system, causing patches of sclerosis (plaques) in the brain and spinal cord.

muscarinic

Referring to agents that stimulate the postganglionic parasympatheticreceptor, named after the prototypical mushroom alkaloid, muscarine [2,5-anhydro-1,4,6-trideoxy-6-(trimethylammonio)-D-ribo-hexitol].

muscarinic receptor

One of the two main classes of acetylcholine receptors (see also nicotinicreceptor) that responds to muscarinic agents.

muscle spindle

neuromuscular spindle

Sensory organ in the body of a striated muscle containing afferent and efferentnerve fibers that detect passive muscle stretch and convey information to the central nervous system to cause reflex resistance to this stretch.

mydriasis

Dilation of the pupil.

See also miosis.

myelin

Electrically insulating lipoprotein layers that are produced by glial cells and surround the axons of the neurons.

Note:It is produced by oligodendrocytes in the central nervous system and by Schwann cells in the peripheral nervous system.

See also myelin sheath.

myelin basic protein

Major component of myelin, that helps organizing the correct assembly of the lipids and proteins in myelin sheets.

myelin-associated glycoprotein

Transmembrane glycoprotein that plays an important role in the interaction between axons and myelin and affects myelination during nerve regeneration.

myelination

The acquisition, development, or formation of a myelin sheath around a nerve fiber.

See also demyelination.

[5]

myelin sheath

Concentric layers of myelin surrounding the axons of some neurons.

[8]

myelogram

X-ray of the spinal canal following injection of a contrast material into the surrounding cerebrospinal fluid spaces.

myelomeningocele

Protrusion of the spinal cord and its coverings through a defect in the vertebral column.

myelopathy

1. Any functional or pathologic disturbance in the spinal cord.

2. Disorder of the myelopoietic tissues of the bone marrow.

myopathy

Any disease of muscle.

myotonia

Prolonged contraction or delayed relaxation of a muscle after mechanical or brief electrical stimulation.

After [5]

NG2 cell

polydendrocyte

Glial cell of the central nervous system, distinct from an oligodendrocyte or astrocyte, that may serve as a precursor of oligodendrocytes, and that takes its name from expression of proteoglycan NG2.

narcosis

Nonspecific, reversible depression of central nervous system function, marked by stupor or unconsciousness.

After [8]

narcotic

1. Nonspecific usage – an agent that produces insensibility or stupor.

2. Specific usage – any natural or synthetic substance that has morphine-like actions.

See also opioid.

After [1]

neocortex

Outer layer of the cerebral cortex that supports higher brain functions, especially cognitive function and language in humans.

neoplasm

New and abnormal formation of tissue as a consequence of growth by cell proliferation that may continue after the initial stimulus that initiated the proliferation has ceased, and may develop into a tumor.

After [1]

nerve

Ensheathed bundle of nerve fibers that conveys information between the central nervous system and other regions of the body.

See also cranial nerve, peripheral nervous system.

nerve cell

See neuron.

nerve conduction study

Measure of the functional integrity of a nerve with a stimulating electrode, placed on the skin over the nerve, and a more distal recording electrode, to determine the velocity of the impulse that passes along the nerve between the electrodes.

nerve conduction velocity

Rate of progression of a nerve impulse in a peripheral nerve or in its largest component nerve fibers.

nerve fiber

Axon with its surrounding myelin sheath.

nerve gas

nerve agent

Volatile chemical with neurotoxic features intended for use in warfare to disable or kill the organism rapidly after inhalation or skin contact, and classified as a prohibited weapon of mass destruction by The Chemical Weapons Convention (CWC).

nerve growth factor (NGF)

One of a family of proteins known as neurotropins that function as signaling molecules to induce axon growth, branching, elongation and survival of neurons.

nerve root

Proximal end of a spinal nerve nearest its attachment to the spinal cord.

nervous system

The entire neuronal apparatus, composed of both the central nervous system and the peripheral nervous system.

After [5]

neural activity

Metabolic and electrical activity of neurons.

neuralgia

Paroxysmal pain extending along the course of one or more nerves.

neural network

neuronal network

A functionally interconnected set of neurons, generally in the central nervous system.

neural stem cell

Multipotent cell, with mitotic potential, that may serve as a precursor for neuroprogenitor cells.

neurectomy

Excision of a nerve or part of a nerve.

neurite

Outgrowth or projection of either an axon or a dendrite from the neuron cell body that is the structural basis of the neural network.

neurite outgrowth

Phenomenon in which neurons tend to send out neurites to make contact with other nerve cells.

neuritic plaque

See amyloid plaque.

neuritis

Inflammation of a nerve.

neurobehavior core test battery (NCTB)

A set of seven tests, recommended by the World Health Organization (WHO) in 1983, to detect neurotoxicity in human populations

neuroblastoma

Tumor originating from the sympathetic nervous system.

neurodegenerative disease

Disease of the brain and (or) peripheral nervous system with progressive loss of neuronal function, accompanied by changes in morphology and subcellular organization of the nervous system.

neurodevelopmental toxicity

1. Adverse effect of a substance that disrupts developmental processes of the nervous system.

2. Toxicity in which the developing nervous system shows heightened sensitivity compared with the adult nervous system.

neuroendocrine (system)

Cooperating network of the nervous system and hormonal system.

neurofibril

Part of a filamentous structure found in the cell body, axons, dendrites, and sometimes synaptic endings of neurons, consisting of bundles of neurofilaments and neurotubules.

neurofibrillary tangle

Intracellular accumulation of aggregates of hyperphosphorylated tau protein or paired helical filaments consisting of the tau protein, a microtubule-associated protein that normally stabilizes the cytoskeleton.

neurofibroma

Tumor of the peripheral nervous system representing an abnormal collection of Schwann cells and connective tissue.

neurofilament

Class of intermediate filament of the neuronal cytoskeleton, providing support for the axon and dendrites.

See also neurofibril.

neurogenesis

Formation of nerve cells or of the nervous system.

neurogenic

1. Originating in, starting from, or caused by, the nervous system or nerve impulses.

2. Relating to neurogenesis.

[5]

neurogenic shock

Condition of decreased blood pressure, slow heart rate and insufficient perfusion of the body with blood, caused by loss of autonomic control (see autonomic nervous system) following acute trauma to the brain or spinal cord.

neurohypophysis

Posterior lobe of the pituitary gland.

neuroimaging

Process of producing images of the structure or activity of the brain or other parts of the nervous system.

neuroinflammation

Complex series of local immune responses within the nervous system to deal with a threat to the neural environment from infection, injury, or trauma.

neuroleptic

Any of a class of psychotropic drugs used to treat psychosis, particularly schizophrenia.

After [5]

neurolysis

1. Breakdown of nervous tissue from disease or injury.

2. Therapeutic destruction of a nerve or nerves to treat intractable pain.

3. Surgical freeing of a nerve from adhesions of the neural sheath.

neuroma

Tumor made up largely of nerve cells.

neuromuscular junction (NMJ)

See motor endplate.

neuron n., /al adj.

nerve cell

Electrically excitable cell type consisting of a cell body, axon, and dendrites that is the basis of brain function and of peripheral sensory and motor activity.

neuronopathy

Disorder involving destruction of the cell bodies of neurons.

neuron-specific enolase

Enzyme of glucose metabolism, normally found in nervous tissue, that catalyzes the dehydration of 2-phosphoglycerate.

neuropathological examination

Application of gross and histopathologic methods to study toxic changes in the morphology and histology of the nervous tissues and the brain.

neuropath/y n., /ic adj.

Pathological change in the peripheral nervous system.

neuropathy target esterase (NTE)

neurotoxic esterase

Enzyme that is phosphorylated by organophosphate compounds and is believed to be involved in the delayed neuropathy of organophosphates.

neuropeptide

One of a group of small proteins (peptides) that serve as neurotransmitters in the brain, autonomic nervous system and neuroendocrine system.

See also endorphin, enkephalin.

neuroprogenitor cell

Precursor cell that is capable of differentiating into specific cell types of the nervous system.

neuroprotective

Agent or property of an agent that protects neurons from damage and (or) from the process of aging or degeneration of the brain.

neuropsychological testing

Assessment, under standardized conditions, of an individual’s brain function as it impacts upon cognitive function, thought processes, behavior and personality.

neurotoxic

Poisonous to structures and (or) functions of the brain and nerves.

neurotoxicant

Substance that can produce functional or structural damage to the nervous system.

neurotoxic esterase (NTE) assay

Test in which delayed neuropathy resulting from hydrolytic cleavage of organophosphate esters is studied with measurement of the responsible enzyme activity,

See also hen test, neuropathy target esterase.

neurotoxicology

Discipline applying principles of both neuroscience and toxicology to study the ability of certain substances to alter nervous system structure or function.

neurotoxic shellfish poisoning (NSP)

Toxic shellfish poisoning characterized by nausea, vomiting, and mild neurological symptoms such as dysarthria, paresthesia, ataxia, and vertigo caused by ingestion of shellfish (specifically, bivalve molluscs) contaminated with the polyether brevetoxin and its derivatives produced by the dinoflagellate Karenia brevis.

neurotoxin

Any substance that has the potential to damage the nervous system.

neurotransmission

Process by which a presynaptic cell, upon excitation, releases a specific agent (a neurotransmitter) that crosses the synapse to stimulate or inhibit the postsynaptic cell.

After [5]

See also neurotransmission, retrograde.

neurotransmission, retrograde

Neurotransmission wherein a neurotransmitter is sent from the postsynaptic to the presynaptic membrane in order to modify a signal.

neurotransmitter

Biochemical that is released upon excitation from a presynaptic membrane, crosses the synaptic space and binds to a receptor on the postsynaptic membrane, where it induces a signal that may be either stimulatory or inhibitory.

neurotropic

neurotrophic

Having an affinity for nerve cells or tissues of the nervous system.

neurotropin

neurotrophin

Family of secreted proteins that promote the survival, differentiation, and function of neurons.

See also nerve growth factor.

neurotubule

Microtubule found in neurons.

See also neurofibril.

neurovascular

1. Relating to both the nervous system and the vascular system.

2. Relating to the vasomotor nerves that supply the walls of the blood vessels.

   After [5]

nicotinic

Referring to a substance or effect that mimics acetylcholine at the neuromuscular junction, at autonomic ganglia and at other locations in the brain.

See also muscarinic.

nicotinic receptor

One of the two main classes of acetylcholine receptors (see also muscarinicreceptor), ligand-gated ion channels that open upon binding nicotine as well as acetylcholine.

nine-hole box test

5–9 hole attention box test

Behavioral test based on the five-choice serial reaction time task, which allows the study of attention based on a test animal learning from which hole (typically one of five open holes in an arc of nine) a visual (light) cue was given, with a food pellet reward for nose-poking the correct hole.

See also nose-poke test.

Nissl body

Nissl granule

Nissl substance

Granular structure consisting of rough endoplasmic reticulum, found in neurons

See also chromatolysis.

nociception

Physiological response to harmful stimuli by specialized nerve endings that transmit a signal perceived as pain by the brain.

See also antinociception.

node of Ranvier

Short interval in the myelin sheath of a nerve fiber where the axon is invested only by scant cytoplasmic processes of the neighboring Schwann cells or, in the central nervous system, of oligodendroglia cells.

noradrenalin

4-[(1R)-2-amino-1-hydroxyethyl]benzene-1,2-diol

Catecholamine hormone acting as a postganglionicadrenergic mediator at α- and β-adrenergicreceptors.

norepinephrine

See noradrenalin.

nose-poke test

Test allowing study of attention deficit based on noting the success of a test animal in gaining a food pellet reward for nosing the correct hole in a box. A specific example is the nine-hole box test.

numbness

Imprecise term for absent or reduced touch perception, as well as paresthesia.

nystagmus

Involuntary rhythmic oscillation of the eyeballs.

After [5]

occipital lobe

One of the four major lobes of each cerebral hemisphere, situated within the occiput, containing most of the neural apparatus of visual processing.

occiput

Posterior part of the head or skull.

olfaction

Detection of odors.

olfactory bulb

Region of the frontal lobe of the brain, receiving input from neurons of the nasal mucosa and involved in the sense of smell.

oligodendrocyte

oligodendroglial cell

Type of glial cell that produces the myelin sheath in the central nervous system.

oligodendroglial cell

See oligodendrocyte.

oligodendroglioma

Glioma arising from the oligodendrocytes.

open field test

Procedure to observe changes in motor activity and rearing, in which a rodent is placed on a surface and distance and patterns of movement are recorded.

operant behavior, schedule-controlled

See schedule-controlled operant behavior.

opiate receptor

One of a group of G-protein-coupled receptors that bind morphine and endogenous substances that have morphine-like effects.

opioid

Synthetic narcotic having properties consistent with binding to opiate receptors, but not derived from opium.

opium

Extract of the opium poppy, Papaver somniferum, containing morphine as a major psychoactive component.

organoleptic

1. Relating to perception by a sensory organ.

2. Involving the use of sensory organs, e.g., organoleptic tests.

organometallic compound

Compound having covalent bonds between one or more metal atoms and one or more carbon atoms of an organyl group.

organophosphate

Organic ester of phosphoric acid.

organophosphate-induced delayed neuropathy (OPIDN)

Disorder, typically with symptoms of pain and weakness in the extremities, resulting from neuronal death associated with organophosphate poisoning (either chronic or a late effect of acute poisoning).

osmophobia

olfactophobia

Morbid fear of odors.

[5]

oxidative stress

Adverse effects occurring when the generation of reactive oxygen species (ROS) in a system exceeds the system’s ability to neutralize and eliminate them; excess ROS can damage a cell’s lipids, protein, and DNA.

[1]

pain

1. Conscious awareness of an unpleasant sensation mediated by nerve conduction of a stimulus from a site of tissue injury to the brain.

   Note 1:	Chemical mediators of pain include histamine, bradykinins, and prostaglandins.
   Note 2:	The sensation may occur or persist when the injured tissue is no longer present, as in phantom pain.

2. Sensation one feels when hurt in body or mind.

   After [9]

pain, neuropathic

Pain initiated by nerve injury, not mediated by nociception.

pain, nociceptive

See nociception.

pain, phantom

phantom limb pain

Sensation that an amputated limb is still present, often associated with pain.

pain receptor

See nociception.

paired helical filament (PHF)

Describing the aggregation of hyperphosphorylated tauprotein into neurofibrillary tangles.

palpitation

1. Unduly rapid or throbbing heartbeat that is noted by a patient; it may be regular or irregular.

2. Undue awareness by a patient of a heartbeat that is otherwise normal.

   [1]

papilledema

Edema of the region of the head of the optic nerve in the retina (the optic disc).

paralysis

Total or partial loss of motor function.

paralytic shellfish poisoning (PSP)

Illness that is a consequence of consumption of bivalve molluscs such as mussels, oysters, and clams that have ingested large quantities of microalgae containing saxitoxin or its derivatives.

paraoxonase

Any of several related enzymes that hydrolyze aryl esters and lactones, notably organophosphate pesticides including the acetylcholinesterase inhibitor, paraoxon.

paraplegia

Paralysis of both lower limbs.

parasympathetic nervous system

Division of the autonomic nervous system involved in stimulating digestive secretions, slowing heart rate, constricting the pupils of the eyes, and dilating blood vessels.

Compare sympathetic nervous system.

After [1]

parasympathomimetic

cholinomimetic

1. n., Substance that produces effects resembling those of impulses transmitted by the postganglionic fibers of the parasympathetic nervous system.

2. adj., Producing effects resembling those of impulses transmitted by the postganglionic fibers of the parasympathetic nervous system.

paresis

Slight or incomplete paralysis.

[1]

paresthesia

paraesthesia

Abnormal or unexplained tingling, pricking, or burning sensation on the skin.

[1]

parietal lobe

One of the four major lobes of each cerebral hemisphere situated between the frontal and occipital lobes, above the temporal lobe.

Parkinson disease

idiopathic parkinsonism

primary parkinsonism

Degenerative disorder of the central nervous system resulting from decreased production of the neurotransmitterdopamine in the basal ganglia (notably the substantia nigra).

parkinsonism, secondary

Neurological syndrome resembling Parkinson disease and often resulting from decreased dopamine production as a consequence of neurodegenerative changes in the substantia nigra.

passive avoidance test

Fear-motivated test in which rodents learn to avoid an otherwise preferred environment in which they are exposed to an aversive stimulus.

paw-reaching test

staircase test

Test used to reveal motor deficits, usually of central origin, exhibited on the contralateral side by reduced ability of a test animal to extend the forelimb.

PC-12 cell

Cell of an established line originally derived from a pheochromocytoma of the rat adrenal medulla.

peripheral nervous system (PNS)

One of the two major divisions of the nervous system, made up of the nerves and ganglia lying outside the brain and spinal cord that transmit sensory and motor signals to and from the central nervous system.

peripheral neuropathy

Neuropathy affecting nerves of the peripheral nervous system.

peristalsis

Progression of a wave of smooth muscle contraction followed by relaxation along the length of a muscular tube.

pesticide

Substance intended to kill pests.

[1]

phenylketonuria (PKU)

Autosomal recessive disorder resulting from mutations that impair the function of the enzyme phenylalanine hydroxylase.

pheochromocytoma

Tumor of the chromaffin cells of the adrenal medulla that results in excessive secretion of norepinephrine and other catecholamines.

pheromone

ectohormone

Substance used in olfactory communication between organisms of the same species to elicit a change in sexual or social behavior.

[1]

phonophobia

Abnormal fear of loud sound, or occasionally of voices.

photophobia

Abnormal visual intolerance of light.

[1]

photoreceptor cell

Specialized neuron found in the retina, involved in detecting light and transducing the signals of vision

pia

pia mater

Innermost of three membranous layers, together composing the meninges (see meninx), that surrounds and adheres to the brain and spinal cord.

pineal gland

epiphysis

Pea-sized conical mass of tissue behind the third ventricle of the brain, secreting the hormone-like substance melatonin in some mammals.

pituitary

hypophysis

pituitary gland

Small endocrine gland sitting in a bony cavity (the sella turcica) at the base of the brain and connected to the hypothalamus.

plexus

Network of interconnecting nerves, blood vessels or lymphatic vessels.

See also ganglion.

pneumotaxic center

pontine respiratory group

Neural network in the brainstem involved in regulating respiration.

poison n., /ous adj.

Substance that, taken into or formed within the organism, impairs the health of the organism and may kill it.

[1]

polarization

See membrane polarization.

polydendrocyte

See NG2 cell.

polyneuritis

Inflammation of several peripheral nerves simultaneously.

polyneuropathy

Neuropathy (distal axonopathy) of the peripheral nervous system, often affecting the extremities in a bilateral distribution, and characterized by numbness, tingling, and paresthesia.

pontine respiratory group

See pneumotaxic center.

Porsolt test

See swimming test.

posterior fossa

Pocket in the back of the skull that accommodates the cerebellum and the midbrain.

postsynaptic

Event or structure at the distal side of a synaptic cleft.

potentiation (in neurology)

post-tetanic potentiation

Increase in strength of synaptic transmission between two neurons after repetitive stimulation of the presynaptic partner.

potentiation, long-term

Potentiation lasting up to several months.

presynaptic

Event or structure at the proximal (transmitting) side of a synaptic cleft.

prodromal stage

Phase before the onset of full-blown disease.

See also prodrome.

prodrome

Symptom(s) heralding impending onset of a disease.

See also prodromal stage.

profile of mood state (POMS) test

Procedure in which a test subject is asked to indicate his/her mood during the past week, by quickly marking specified emotional words on a scale between “not at all” and “extremely.”

proprioception

Sense of the movement or position of the body independent of vision.

See also proprioceptor.

After [5]

proprioceptor

Sensory organ in a muscle, tendon or joint capsule that senses position or state of contraction.

After [5]

prosencephalon

forebrain

Anterior part of the brain, including the cerebral hemispheres, the thalamus, and the hypothalamus.

proximal

Nearest the point of origin or closest to the medial plane of the body.

After [5]

pseudobulbar affect (PBA)

Involuntary emotional outburst (typically crying or laughing).

pseudocholinesterase

See butyrylcholinesterase.

pseudomeningocele

Part of the cerebrospinal fluid that, in contrast to a meningiocele, is not surrounded by dura.

pseudotumor cerebri

idiopathic intracranial hypertension

Disorder with increased intracranial pressure, cerebral edema, and frequently papilledema, symptoms that resemble the effects of a tumor but without the occurrence of one.

psychoactive

Having the ability to alter mood, behavior, cognitive function or mental state.

After [5]

Compare psychotropic.

psychoneuroimmunology (PNI)

Study of links between the brain and the immune system, recognizing an interaction between psychological states and the outcome of immune responses to disease.

psycho/sis n., /tic adj.

Disordered thought processes that may include changes in cognitive function, perception, belief, behavior and personality; altered awareness of reality.

psychosis, organic

organic brain syndrome

Psychosis with a known physical (anatomic, disease-related or toxic) cause.

psychotropic

Capable of affecting the mind, emotions and behavior.

After [5]

Compare psychoactive.

puffer fish

Marine fish of the order Tetraodontiformes and family Tetraodontidae.

See also tetrodotoxin.

Purkinje cell

Large neuron forming part of a layer of cells in the cerebellum.

pursuit aiming test

Procedure in which a subject is instructed to place a dot in defined sites (such as a number of circles), as quickly as possible.

See also neurobehavior core test battery.

putamen

Part of the basal ganglia that plays a role in coordinating movement and learning.

pyknosis

Clumping of nuclear chromatin and shrinkage of the cell nucleus during cell degeneration.

pyramidal cell

Large neuron of the cerebral cortex having a triangular cell body in histological section with several dendrites at the base and one large apical axon.

pyramidal system

See motor system.

pyrethrin

See pyrethroid.

pyrethroid

Synthetic molecule with structural similarity to the natural pyrethrins found in plants of the genus Chrysanthemum.

quadriplegia

Paralysis of both upper and both lower limbs.

radial arm maze

Apparatus with a central platform and equidistant arms (usually eight), at the end of which is a reward (e.g., a food pellet).

See also maze, water maze test.

radiculitis

Inflammation of the spinal nerve roots leading to pain and hyperesthesia radiating along the nerve.

reaction time

Time between an inducing sensory stimulus and a measured physiological response.

See also simple reaction time test.

rearing (in toxicity testing)

Of a rodent or other animal raising itself on its hind legs.

rebound

Reappearance of original symptom(s), often exacerbated, following cessation of treatment.

See also headache, rebound.

receptor

Molecule that binds to a ligand, thus leading to biochemical signaling inside the cell.

[3]

β-receptor

See β-adrenergic receptor.

reflex

Involuntary reaction in response to a stimulus applied to the periphery following its transmission to the nervous centers in the brain or spinal cord.

After [5]

reflex sympathetic dystrophy (RSD)

Diffuse persistent pain usually in an extremity.

After [5]

reinforcement (in psychology)

Use of a stimulus in operant conditioning to increase the likelihood that a particular behavior will occur.

relaxant

Agent that reduces muscle tension.

See also relaxation.

relaxation

Reduction in or release of tension, as in reversal of muscle contraction, relief of anxiety, etc.

reperfusion

Restoration of the blood supply to an organ or tissue following a period of ischemia.

repolarization

Returning of a cell’s membrane potential to its resting potential following depolarization.

resolution phase

Return to a sexually unexcited state following orgasm.

resting potential

Baseline membrane potential.

resting tremor

See tremor.

retina

Multilayered structure lining the inner surface of the eye, containing photoreceptor cells and the neural components for transmission of signals to the optic nerve.

retrograde axonal transport

Transport of material from the nerve ending back to the cell body.

See also axonal transport.

reuptake

Transporter-dependent resequestration of a neurotransmitter by a presynapticneuron, terminating synaptic transmission.

Rey–Osterrieth complex figure (ROCF) test

Procedure in which the test subject first copies a complicated drawing and then is asked to draw it from memory.

righting reflex

Reflex that restores the correct orientation of the body when taken out of the upright position.

righting test

righting test, aerial

Experimental measurement of an animal’s (usually a rodent’s) ability to land in an upright position at the end of a fall.

See also righting reflex.

righting test, elevated

See rotarod test.

righting test, surface

Test animal is placed on its back and the time to retain an uprate position with four paws in contact with the surface is measured.

rod cell

See photoreceptor cell.

rotarod test

Experimental observation of an animal’s (usually a rodent’s) ability to stay on a rotating rod without falling off.

saccadic eye movement

Rapid or jerky movement of the eyes from one line of sight to another, as in reading or correction of a jerky nystagmus.

After [5]

sagittal

Vertical (longitudinal) plane dividing the body into right and left sections.

Saint Anthony fire

1. See ergotism.

2. Referring to inflammatory conditions of the skin such as erysipelas.

Santa Ana dexterity test

Procedure in which a test subject stands in front of a plate with 48 square holes and an equal number of fitted pegs, each having a cylindrical upper part and square base, and is asked to fit the pegs into the holes as quickly as possible by turning them 180 degrees, first with one hand and in a subsequent trial with the other hand.

See also neurobehavior core test battery.

schedule-controlled operant behavior (SCOB)

Experimental procedure in which operant behavior (see conditioning, operant) is assessed following a conditioning stimulus delivered at a pre-determined duration and frequency (‘schedule of reinforcement’), thus allowing comparison of the effects of magnitude, frequency and duration of the stimulus.

schedule of reinforcement

Frequency, duration, dose, and (or) intensity of a conditioning stimulus (see stimulus, conditioned).

See also schedule-controlled operant behavior.

Schwann cell

Glial cell in the peripheral nervous system that produces myelin for the axons of the peripheral nerves.

sclerosis

Hardening of an organ or tissue, especially that due to excessive growth of fibrous tissue.

[1]

Scombroid poisoning

Constellation of symptoms resembling an allergic reaction, caused by eating the meat of decaying fish that has high levels of histamine (in this context sometimes referred to as scombrotoxin).

sedative

Substance that exerts a soothing or tranquillizing effect, or describing the effect itself.

After [1]

Compare tranquilizer.

seizure

Sudden change in neural activity, leading to convulsions and (or) changes in consciousness of varying degrees of severity.

See also epilepsy.

selective serotonin reuptake inhibitor (SSRI)

Drug in a subclass of substances that interfere with the resequestration of serotonin by the presynaptic membrane.

senile plaque

See amyloid plaque.

senil/ity n., /e adj.

Characteristics typically associated with old age, especially relating to memory loss and other mental impairment.

See also dementia.

sensory neuron

Nerve cell specialized for detecting and transducing signals from external or somatic stimuli.

serotonin

See 5-hydroxytryptamine.

serotoninergic

Relating to a nerve that releases or responds to serotonin as a neurotransmitter.

shellfish poisoning

Illness associated with consumption of seafood contaminated with toxins.

shunt

n. Fistula or prosthetic device that diverts fluid from one system to another.

vb. To bypass or divert.

After [5]

sick building syndrome

Health effects or loss of a sense of well-being associated, by those who experience it, with time spent in a certain building or room.

silver staining

Method for visualization of macromolecules such as nucleic acids and proteins, typically in electrophoretic gels or formalin-fixed histological sections, based on the reduction of silver salts to metallic silver or formation of crystalline silver compounds.

See also Golgi staining.

simple reaction time test

Procedure to assess psychomotor speed in which a test subject is presented at irregular intervals with a visual stimulus, such as a coloured dot on a screen, and is asked to press a button immediately after noticing the stimulus.

See also neurobehavior core test battery.

SLUDDE

SLUDGE

Acronym for the constellation of signs salivation, lacrymation, urination, defecation, dyspnea/gastrointestinal upset, and emesis.

social interaction test

Behavioral test wherein a rodent stranger is placed in the cage of a domestic rodent and intensities and duration of interactions (e.g., sniffing, aggression, avoidance) between the socially unacquainted animals are observed.

soporific

Substance producing sleep.

[1]

spasm

Sudden involuntary contraction of one or more muscles; includes cramps and contractures.

[5]

spasmolytic

Agent that relieves smooth muscle spasms.

After [5]

spastic

Relating to spasticity.

spasticity

Increased muscle tone at rest, characterized by resistance to passive stretch.

After [5]

sphingolipid

Member of a class of lipids containing the aliphatic amino alcohol sphingosine, or related structures, thus including ceramide.

sphingomyelin

One of a family of phospholipids found especially in the central nervous system, containing 1-phosphocholine bound to a ceramide.

sphingosine

2-aminooctadec-4-ene-1,3-diol

Major lipid component of cell membranes.

See also sphingolipid, sphingomyelin.

spina bifida

Failure of the neural tube to close, resulting in the absence of part of the arch of the spinal column and exposure of the spinal cord and its covering membranes.

spinal cord

Portion of the central nervous system outside the brain and inside the vertebral column.

spinal tap

See lumbar puncture.

spine

See vertebral column.

staircase test

See paw-reaching test.

startle reaction

startle response

startle part

Rapid physiological and psychological response to a sudden, unexpected stimulus that includes muscle contraction (see contracture) and avoidance posturing, with an increase in heart rate, respiration, skin conductance, and a negative affect.

startle reflex

The earliest brainstem-mediated part of the reflex reaction to a stimulus perceived as threatening.

startle response test

See startle reaction.

startle response test, acoustic

Neurophysiological examination in which an animal is exposed to a brief (e.g., 40 ms) acoustic stimulus, followed by measurement of the animal’s motor reaction.

See also startle reaction.

status epilepticus

Repeated or prolonged seizure lasting more than 30 min.

stenosis

Narrowing or stricture of a channel, as of a blood vessel or muscular tube.

stereology

Three dimensional interpretation of two dimensional cross sections of tissue and other materials.

stereology, unbiased

Stereological method that uses systematic analysis of defined spatial fractions of a sample to estimate numbers of neuronal nuclei independent of changes in size and shape that may occur during tissue processing.

stimulant

Agent that rouses or increases mental or physical activity.

stimulus

1. Anything that produces a reaction in an organism.

2. That which causes a response in an excitable tissue (see excitation) such as a nerve, muscle or gland.

stimulus, conditioned

Stimulus that comes to evoke a response after repetitive pairing with another stimulus that automatically elicits that response.

Compare stimulus, unconditioned. See also classical conditioning.

stimulus, unconditioned

Stimulus that automatically elicits a paired response, such as food eliciting salivation in a hungry animal.

Compare stimulus, conditioned.

striatum

Subcortical structure of striations of gray matter and white matter in the forebrain that serves as the major input to the basal ganglia, specifically the caudate nucleus, the putamen and the striated structure linking them.

See also corpus striatum.

stroke (in neuroscience)

Acute impairment of circulation to a part of the brain, lasting more than 24 h.

After [5]

stupor

State of impaired consciousness showing diminution in response to environmental stimulation.

After [5]

subarachnoid

Underneath the arachnoid membrane.

subarachnoid hemorrhage

Loss of blood into the space between the arachnoid membrane and the pia mater.

subdural

Between the dura mater and the arachnoid membrane.

substantia nigra

Component of the basal ganglia involved in production of the neurotransmitterdopamine.

See also parkinsonism.

sudorific

See diaphoretic.

supratentorial

Intracranial contents located above the tentorium of the cerebellum, notably the white matter of the cerebrum, often describing functional symptoms of diseases of the white matter that lead to physical and mental disability.

supratentorial herniation

Abnormal protrusion of brain structures into compartments above the tentorium, or over the edge of the tentorium, due to increased intracranial pressure.

swimming test

forced swimming test

Porsolt forced swimming test

behavioral despair test

Procedure in which a test animal (rodent) is forced to swim to avoid drowning.

Compare tail suspension test.

sympathetic nervous system

Part of the autonomic nervous system originating in the thoracic and lumbar regions of the spinal cord that tends to inhibit or oppose the physiological effects of the parasympathetic nervous system, as in tending to reduce digestive secretions, increase the heart rate, and contract blood vessels.

[1]

sympathomimetic

adrenergic

1. n., Substance that produces effects resembling those of impulses transmitted by the postganglionic fibers of the sympathetic nervous system.

2. adj., Having the property of producing such effects.

   After [1]

synap/se n., /tic adj.

Functional junction between two neurons, where a nerve impulse is transmitted from one neuron to another, by neurotransmitters.

After [1]

synaptic cleft

Narrow gap between the presynaptic and postsynaptic regions of two communicating neurons, into which neurotransmitters are secreted.

See also synapse.

synaptic inhibition

Suppression of synaptic transmission.

See also inhibitory post-synaptic potential.

synaptic plasticity

1. Ability of synapses to form and reform continually, including to allow learning.

2. Malleability of signal strength arising at the level of synaptic transmission.

See also augmentation, facilitation, long-term potentiation, potentiation.

synaptic stripping

Removal of dysfunctional synapses.

See also microglial cell.

synaptic transmission

Neurotransmitter release, diffusion, and receptor binding, propagating an impulse across a synapse.

syringomyelia

syrinx

Cyst occurring within the spinal cord as a result of accumulation of cerebrospinal fluid.

T-maze

Simple type of test apparatus with three arms shaped like the letter “T.” After placing a rodent in the middle, it is recorded how often the animal enters each arm.

See also maze.

tachycardia

Antonym: bradycardia

Abnormally fast heartbeat.

[1]

tail flick test

Procedure in which the tail of a rodent is heated and the time taken for the animal to flick its tail (latency) is taken as a measure of the relative degree of antinociception.

See also tail immersion test.

tail immersion test

Procedure in which the tail of a rodent is placed in a hot water bath (typically between 54°C and 58°C) and the time it takes the animal to remove the tail from the water is interpreted as a measurement of the relative degree of antinociception.

See also tail flick test.

tail suspension test

Procedure in which a mouse is suspended by its tail and the time spent attempting to right itself is observed.

tapping test

See finger tapping test.

tauopathy

One of a class of neurodegenerative diseases, including Alzheimer disease, associated with abnormal aggregation of tau proteins.

See also paired helical filament, Western Pacific amyotrophic lateral sclerosis and parkinsonism–dementia complex.

tau protein

One of a class of proteins that stabilizes microtubules, particularly in neurons, astrocytes, and oligodendrocytes of the central nervous system.

TDP-43 transcription factor

Cleavage product (43 kDa) of the transactive response (TAR) DNA binding protein (TARDBP) that targets TAR DNA and transcriptionally represses HIV-1.

Teleky’s sign

See wrist drop.

temperature sensitivity

1. Adverse responsiveness to heat or cold.

   Note:

   It is associated with a number of medical conditions, some physiologically well-defined (as in cold intolerance in hypothyroidism) and others less so (as in reported chronic fatigue syndrome).

2. Phenotype arising from engineered or selected gene mutations in experimental organisms characterized by an altered temperature permissive for optimal growth or survival.

temporal lobe

One of the four major lobes of each cerebral hemisphere, situated at the base of the brain.

tentorium

tentorium cerebelli

Fold of the dura mater separating the cerebrum from the cerebellum.

tetanic

Pertaining to tetanus, characterized by tonic muscle spasm.

[1]

tetanus

1. Sustained muscle contraction.

2. Disease caused by tetanus toxin and characterized by painful, sustained muscle contraction with spasticity and paralysis.

tetanus toxin

tetanospasmin

Neurotoxin produced by the bacterium Clostridium tetani growing in anaerobic conditions, producing the disease tetanus.

tetanus toxin-binding ganglioside

Ganglioside that binds tetanus toxin, facilitating its internalization at the presynapticneuronal membrane.

tetany

Neurological syndrome characterized by muscle twitches, cramps, and spasms; and in severe forms, by spasm of the muscles of the larynx (laryngospasm) and seizures.

tetrad test

Battery of tests typically for the effects of cannabinoids in rodents that includes hypomotility assessed by an open field test, catalepsy assessed by the bar test, hypothermia measured by rectal temperature, and analgesia measured by avoidance of heat, e.g., in the tail immersion test.

tetrodotoxin (TTX)

4R,4aR,5R,6S,7S,8S,8aR,10S,12S)-2-azaniumylidene-4,6,8,12-tetrahydroxy-6-(hydroximethyl)-2,3,4,4a,5,6,7,8-octahydro-1H-8a,10-methano-5,7-(epoxymethanooxy)quinazolin-10-olate

Neurotoxin that inhibits action potentials by blocking sodium ion channels.

tetrodotoxin (TTX)-insensitive

Denoting a class of sodium ion channels, found mainly in the heart, that is not blocked by tetrodotoxin.

thalamus

Paired midline structure of the vertebrate brain that surrounds the third ventricle, relays information on sensation, movement and spatial sense to the cerebral cortex, and plays a role in the regulation of wakefulness.

thigmotaxis

Movement of an organism toward or away from a mechanical stimulus, physical contact, or spatial discontinuity, as in movement away from touch by a physical stimulus or exploring close to a wall.

thoracic spine

Portion of the vertebral column of the upper back, between the cervical spine and lumbar spine, in humans consisting of 12 vertebrae designated T1 to T12.

threshold potential

Level of depolarization that must be reached to trigger an action potential in an excitable cell.

See also excitation, hyperpolarization.

thrombus

Clot in the cardiovasculature formed from components of the blood, which may be attached to the vessel wall and (or) occlusive.

tic douloureux

See trigeminal neuralgia.

tingling

Pricking type of paresthesia.

[5]

tinnitus

Continual noise in an ear, such as ringing, buzzing, roaring, or clicking.

[1]

toleran/ce n., /t adj.

1. Becoming less responsive to a stimulus, especially following continued exposure.

2. Resisting the action of a poison or drug taken repeatedly or in large doses.

   After [5]

tomography

Construction of an image of a three-dimensional structure from a series of planar sections obtained with penetrating waves.

torticollis

wry neck

Spasmodic contraction of neck muscles drawing the head to one side with the chin pointing to the other side.

toxicant

See toxic substance.

toxic shellfish poisoning

See shellfish poisoning.

toxic substance

Substance causing injury to living organisms as a result of physicochemical interactions.

[1]

toxin

Poison produced by a biological organism such as a microbe, animal, plant, or fungus.

[1]

tranquilizer

Drug that calms and pacifies with minimal sedating or depressant effects.

transcutaneous electronic nerve stimulation (TENS)

Electrical stimulus applied across the skin to excite nerves for therapeutic purposes.

transsynaptic

Referring to an event, such as transmission of a nerve impulse, across a synapse.

transtentorial herniation

Bulging of brain tissue from the cerebrum through the notch of the tentorium, caused by increased intracranial pressure.

treadmill test

Procedure used to assess limb function and strength, often to evaluate models of peripheral neuropathy, in which a rodent is placed in an enclosed lane upon a surface that can be made to move at variable speed in a retrograde manner, thus allowing observation of the animal’s gait dimension during sustained attempt at forward motion.

tremor

Repetitive, often regular and usually involuntary oscillatory movement caused by alternating contractions of opposing muscle groups.

After [5]

trigeminal nerve

Fifth cranial nerve, supplying sensation to the face and controlling motor activity of mastication.

trigeminal neuralgia

tic douloureux

Severe, paroxysmal bursts of pain in one or more branches of the trigeminalnerve, often induced by touching trigger points in or about the mouth.

[5]

triptan

Member of a class of drugs based on tryptamine that act as serotonin receptor agonists.

tumor

tumour

Any abnormal swelling or growth of tissue, whether benign or malignant.

Compare neoplasm.

[1]

unconscious

1. Not in a conscious state.

2. In psychoanalytic theory, describing feelings and motivations of which one is unaware that nevertheless shape behavior.

uncus

Anterior projection of the gray matter surrounding the hippocampus, covered by a region of the temporal lobe, involved in olfaction.

upper motor neuron

Neuron whose cell body lies in the cerebral cortex or brainstem and whose axon carries impulses to a lower motor neuron.

vagus nerve

Tenth cranial nerve, arising from the medulla oblongata.

vasoconstriction

Decrease in the diameter of the lumen of a blood vessel (especially in the arteries and arterioles) as a result of contraction of smooth muscles in the vessel walls.

Antonym vasorelaxation.

vasodilator

Agent that induces vasorelaxation.

vasopressor

vasoconstrictor

pressor

Agent that induces vasoconstriction.

vasorelaxation

vasodilation

vasodilatation

Increase in the diameter of the lumen of the blood vessels as a result of relaxation of smooth muscles in the vessel walls.

Antonym vasoconstriction.

vasospasm

angiospasm

Contraction of the muscular wall of blood vessels with sustained vasoconstriction possibly leading to tissue ischemia.

venom

Animal toxin generally used for self-defense or predation and usually delivered by a bite or sting.

[1]

ventricle

Normal cavity within an organ, as in the brain or heart.

ventriculo-atrial shunt

Surgical shunt draining cerebrospinal fluid into a cardiac atrium, to relieve pressure in hydrocephalus.

ventriculogram

Radiographic image of the cerebralventricles.

ventriculomegaly

Enlargement of the cerebralventricles.

See also hydrocephalus.

ventriculo-peritoneal shunt

Surgical shunt draining cerbrospinal fluid into the peritoneum of the abdominal cavity, to relieve pressure in hydrocephalus.

vermis (in neuroanatomy)

vermis cerebelli

Narrow central part of the cerebellum between the two cerebellar hemispheres.

vertebra

One of the bony segments that together make up the bony column surrounding the spinal cord.

vertebral column

spine

Bony structure consisting of the vertebrae and enclosing the spinal cord.

vertigo

Dizziness; an illusion of movement as if the external world were revolving around one’s self or as if one’s self were revolving in space.

[1]

vigilance

Ability to maintain concentration or sustain attention over prolonged periods of time.

vigilance decrement

Decreased vigilance measured as a decline in the ability to maintain an accurate voluntary response to signals with time.

visual cortex

Part of the cerebral cortex located in the occipital lobe, responsible for processing the images of sight.

voltage-gated ion channel

Ion channel that opens and closes in response to changes in membrane potential.

Compare ligand-gated ion channel.

water maze test

Morris water maze test

water navigation test

Procedure in which a rat or mouse is placed in a pool of water and observed to swim, using visual environmental clues, to an invisible submerged platform that allows escape from the water.

See also Biel water maze, maze, water maze test.

Wernicke aphasia

fluent aphasia

receptive aphasia

sensory aphasia

Type of aphasia associated with damage to Wernicke’s area or alternatively the medial temporal lobe of the brain, characterized by preservation of speech but with loss of meaningful language and language comprehension.

Wernicke’s area

Region of the brain in superior temporal gyrus of the dominant hemisphere, associated with comprehension of written and spoken language.

Wernicke-Korsakoff syndrome

alcoholic encephalopathy

Co-existence of Wernicke encephalopathy (with gait, ocular and mental disturbances) and Korsakoff psychosis (severe memory loss, often with aphasia, apraxia or agnosia) caused by vitamin B1 deficiency in the context of chronic alcohol abuse.

Western Pacific amyotrophic lateral sclerosis and parkinsonism–dementia complex (ALS-PDC)

Neurodegenerative disease observed in the islands of Guam, Indonesia, Japan and Papua New Guinea, showing combinations of characteristics of amyotrophic lateral sclerosis, atypical parkinsonism with dementia, or dementia alone that may present sequentially during life.

white matter

substantia alba

Portion of the brain and spinal cord consisting mainly of myelinated axons and glial cells.

Wisconsin card sorting test (WCST)

Procedure in which cards, depicting different arrangements, numbers, and colors of symbols, are presented to the test subject, who is asked to make the most appropriate match of a test card without further instructions.

withdrawal

Cessation of exposure to a substance, being characterized by adverse symptoms.

withdrawal effect

Adverse event following withdrawal from a person or animal of a drug to which they have been chronically exposed or on which they have become dependent.

Wolfgram protein

Acidic proteolipid protein component of central nervous system myelin.

wrist drop

radial nerve palsy

Inability to extend the wrist as a result of peripheral nerve damage, causing drooping of the hand.

Y-maze

See T-maze.

zebrafish

Tropical fish (Danio rerio) about 4 cm long, commonly used as a model organism in developmental biology.

Membership of sponsoring bodies

Membership of the Committee of the Chemistry and Human Health Division during the preparation of this report (2014-2015) was as follows:

President: T. Perun; Vice President: R. Cornelis; Secretary: M. Schwenk; Titular Members: E. Differding, J. Fischer, V. Gubala, H. P. Illing, L. Johnston, H. Møller Johannessen, and W. Temple; Associate Members: V. Abbate, M. Kiilunen, Y. Martin, S. Mignani, and D. Rotella; National Representatives: S. Alihodžić, S. Bachurin, B. Haug, R. J.-R. Hwu, R. Leurs, N. Nahar, P. Ploypradith, A. Rahatgaonkar, G. B. Teh, and M. X. Wang