Volume 27, Issue 2

Respiratory viruses as a major threat to human and animal health today are still a leading cause of worldwide severe pandemics. Although the primary target tissue of these viruses is the lung, they can induce immediate or delayed neuropathological manifestations in humans and animals. Already after the Spanish flu (1918/20) evidence accumulated that neurological diseases can be induced by respiratory viral infections as some patients showed parkinsonism, seizures, or dementia. In the recent outbreak of COVID-19 as well patients suffered from headache, dizziness, nausea, or reduced sense of smell and taste suggesting that SARS-CoV2 may affect the central nervous system (CNS). It was shown that different respiratory viral infections can lead to deleterious complications in the CNS by a direct invasion of the virus into the brain and/or indirect pathways via proinflammatory cytokine expression. Therefore, we will discuss in this review mechanisms how the most prevalent respiratory viruses including influenza and coronaviruses in humans can exert long-lasting detrimental effects on the CNS and possible links to the development of neurodegenerative diseases as an enduring consequence.

Progress in microscopy technology has a long history of triggering major advances in neuroscience. Super-resolution microscopy (SRM), famous for shattering the diffraction barrier of light microscopy, is no exception. SRM gives access to anatomical designs and dynamics of nanostructures, which are impossible to resolve using conventional light microscopy, from the elaborate anatomy of neurons and glial cells, to the organelles and molecules inside of them. In this review, we will mainly focus on a particular SRM technique (STED microscopy), and explain a series of technical developments we have made over the years to make it practical and viable in the field of neuroscience. We will also highlight several neurobiological findings on the dynamic structure-function relationship of neurons and glia cells, which illustrate the value of live-cell STED microscopy, especially when combined with other modern approaches to investigate the nanoscale behavior of brain cells.

Psychiatric disorders are common and seem to increase in prevalence worldwide. Most scientific approaches for this phenomenon fail to explain why the majority of mental disorders, unlike most somatic diseases, manifest in early adulthood, why individuals are not more resilient, and why some genes increasing the risk for mental disorders have not been selected against. In this article, an evolutionary perspective on mental health and disorder is taken. This perspective suggests that mismatches between ancestral and contemporary environments contribute to the risk for mental disorders. In addition, predictions from attachment theory and life history theory can explain individual differences with regard to the risk of developing a psychiatric or psychosomatic disorder. Insights from evolutionary approaches to psychiatric and psychosomatic disorders may contribute to improve the prevention and treatment of mental disorders.

Animals have evolved within the framework of microbes and are constantly exposed to diverse microbiota. Microbes colonize most, if not all, animal epithelia and influence the activity of many organs, including the nervous system. Therefore, any consideration on nervous system development and function in the absence of the recognition of microbes will be incomplete. Here, we review the current knowledge on the nervous systems of Hydra and its role in the host–microbiome communication. We show that recent advances in molecular and imaging methods are allowing a comprehensive understanding of the capacity of such a seemingly simple nervous system in the context of the metaorganism. We propose that the development, function and evolution of neural circuits must be considered in the context of host–microbe interactions and present Hydra as a strategic model system with great basic and translational relevance for neuroscience.