Volume 28, Issue 2

Cellular network architecture plays a crucial role as the structural substrate for the brain functions. Therefore, it represents the main rationale for the emerging field of connectomics, defined as the comprehensive study of all aspects of central nervous system connectivity. Accordingly, in the present paper the main emphasis will be on the communication processes in the brain, namely wiring transmission (WT), i.e. the mapping of the communication channels made by cell components such as axons and synapses, and volume transmission (VT), i.e. the chemical signal diffusion along the interstitial brain fluid pathways. Considering both processes can further expand the connectomics concept, since both WT-connectomics and VT-connectomics contribute to the structure of the brain connectome. A consensus exists that such a structure follows a hierarchical or nested architecture, and macro-, meso- and microscales have been defined. In this respect, however, several lines of evidence indicate that a nanoscale (nano-connectomics) should also be considered to capture direct protein-protein allosteric interactions such as those occurring, for example, in receptor-receptor interactions at the plasma membrane level. In addition, emerging evidence points to novel mechanisms likely playing a significant role in the modulation of intercellular connectivity, increasing the plasticity of the system and adding complexity to its structure. In particular, the roamer type of VT (i.e. the intercellular transfer of RNA, proteins and receptors by extracellular vesicles) will be discussed since it allowed us to introduce a new concept of ‘transient changes of cell phenotype’, that is the transient acquisition of new signal release capabilities and/or new recognition/decoding apparatuses.

Redox processes are key events in the degenerative cascade of many adult-onset neurodegenerative diseases (NDs), but the biological relevance of a single redox change is often dependent on the redox couple involved and on its subcellular origin. The biosensors based on engineered fluorescent proteins (redox-sensitive GFP [roGFP]) offer a unique opportunity to monitor redox changes in both physiological and pathological contexts in living animals and plants. Here, we review the use of roGFPs to monitor oxidative stress in different three adult-onset NDs: Alzheimer’s disease (AD), Parkinson’s disease (PD), and amyotrophic lateral sclerosis (ALS). Despite the many differences spanning from incidence to onset, the hypotheses on biological processes underlying both sporadic and familiar ND forms in humans outline a model in which noncompeting mechanisms are likely to converge in various unsuccessful patterns to mediate the selective degeneration of a specific neuronal population. roGFPs, targeted to different cell compartments, are successfully used as specific markers of cell toxicity, induced by expression of causative genes linked to a determined ND. We also report the use of roGFP to monitor oxidative stress induced by the expression of the ALS-causative gene SOD1.

Reticulon 3 (RTN3), which is a member of the reticulon family of proteins, has a biochemical function of shaping tubular endoplasmic reticulum. RTN3 has also been found to interact with β-site amyloid precursor protein cleaving enzyme 1 (BACE1), which initiates the generation of β-amyloid peptides (Aβ) from amyloid precursor protein. Aβ is the major proteinaceous component in neuritic plaques, which constitute one of the major pathological features in brains of Alzheimer’s disease (AD) patients. Mice deficient in or overexpressing RTN3 have altered amyloid deposition through effects on BACE1 expression and activity. In this review, we will summarize the current findings concerning the role of RTN3 in AD pathogenesis and demonstrate that RTN3 protein levels act as age-dependent modulators of BACE1 activity and Aβ deposition during the pathogenic progression of AD.

The ATP-binding cassette (ABC) transporter superfamily is a large family of proteins that transport specific molecules across membranes. These proteins are associated with both cholesterol metabolism and Alzheimer’s disease (AD). Cholesterol homeostasis has a key role in AD, and ABC transporters are important mediators of lipid transportation. Emerging evidence suggests that decreased expression and hypofunction of ABC transporters are crucial to the occurrence and development of AD. In the present article, we review the current knowledge regarding ABC transporters and speculate on their role in the pathogenesis of AD.

Several studies have aimed to address the natural inability of humankind to detect deception and accurately discriminate lying from truth in the legal context. To date, it has been well established that telling a lie is a complex mental activity. During deception, many functions of higher cognition are involved: the decision to lie, withholding the truth, fabricating the lie, monitoring whether the receiver believes the lie, and, if necessary, adjusting the fabricated story and maintaining a consistent lie. In the previous 15 years, increasing interest in the neuroscience of deception has resulted in new possibilities to investigate and interfere with the ability to lie directly from the brain. Cognitive psychology, as well as neuroimaging and neurostimulation studies, are increasing the possibility that neuroscience will be useful for lie detection. This paper discusses the scientific validity of the literature on neuroimaging and neurostimulation regarding lie detection to understand whether scientific findings in this field have a role in the forensic setting. We considered how lie detection technology may contribute to addressing the detection of deception in the courtroom and discussed the conditions and limits in which these techniques reliably distinguish whether an individual is lying.

Transcranial direct current stimulation (tDCS) is a neuromodulatory noninvasive brain stimulation tool with potential to increase or reduce regional and remote cortical excitability. Numerous studies have shown the ability of this technique to induce neuroplasticity and to modulate cognition and behavior in adults. Clinical studies have also demonstrated the ability of tDCS to induce therapeutic effects in several central nervous system disorders. However, knowledge about its ability to modulate brain functions in children or induce clinical improvements in pediatrics is limited. The objective of this review is to describe relevant data of some recent studies that may help to understand the potential of this technique in children with specific regard to effective and safe treatment of different developmental disorders in pediatrics. Overall, the results show that standard protocols of tDCS are well tolerated by children and have promising clinical effects. Nevertheless, treatment effects seem to be partially heterogeneous, and a case of a seizure in a child with previous history of infantile spasms and diagnosed epilepsy treated with tDCS for spasticity was reported. Further research is needed to determine safety criteria for tDCS use in children and to elucidate the particular neurophysiological changes induced by this neuromodulatory technique when it is applied in the developing brain.

Vitamin D has been considered as neurosteroid, and its pivotal role in neuroprotection, brain development, and immunomodulation has been noticed in studies; however, our knowledge regarding its role in neurological disorders is still developing. The potential role of vitamin D in the pathophysiology and treatment of epilepsy, as one the most prevalent neurological disorders, has received less attention in recent years. In this article, we review the possible relationship between vitamin D and epilepsy from different aspects, including the action mechanism of vitamin D in the central nervous system and ecological and epidemiological findings. We also present the outcome of studies that evaluated the level of vitamin D and the impact of administrating vitamin D in epileptic patients or animal subjects. We also review the current evidence on interactions between vitamin D and antiepileptic drugs.

Here, we provide a review of behavioural, cognitive, and neural studies of the thalamus, including its role in attention, consciousness, sleep, and motor processes. We further discuss neuropsychological and brain disorders associated with thalamus function, including Parkinson’s disease, Alzheimer’s disease, Korsakoff’s syndrome, and sleep disorders. Importantly, we highlight how thalamus-related processes and disorders can be explained by the role of the thalamus as a relay station.