No abstract

The concept of neurovascular unit (NVU), formalized at the 2001 Stroke Progress Review Group meeting of the National Institute of Neurological Disorders and Stroke, emphasizes the intimate relationship between the brain and its vessels. Since then, the NVU has attracted the interest of the neuroscience community resulting in considerable advances in the field. Here the current state-of-knowledge of the NVU will be assessed, focusing on one of its most vital roles: the coupling between neural activity and blood flow. The evidence supports a conceptual shift in the mechanisms of neurovascular coupling, from a unidimensional process involving neuronal-astrocytic signaling to local blood vessels, to a multidimensional one in which mediators released from multiple cells engage distinct signaling pathways and effector systems across the entire cerebrovascular network in a highly orchestrated manner. The recently appreciated NVU dysfunction in neurodegenerative diseases, although still poorly understood, supports emerging concepts that maintaining neurovascular health promotes brain health.

Neurological complications have emerged as a significant cause of morbidity and mortality in the ongoing COVID-19 pandemic. Beside respiratory insufficiency, many hospitalized patients exhibit neurological manifestations ranging from headache and loss of smell, to confusion and disabling strokes. COVID-19 is also anticipated to take a toll on the nervous system in the long term. Here, we will provide a critical appraisal of the potential for neurotropism and mechanisms of neuropathogenesis of SARS-CoV-2 as they relate to the acute and chronic neurological consequences of the infection. Finally, we will examine potential avenues for future research and therapeutic development.