The Neurovascular Unit in Health and Disease

Over the past 10 years, study of the blood vessel in cerebrovascular disease has expanded from consideration of only endothelial cells to include interactions with neurons, astrocytes, pericytes, and extracellular matrix. The role of other cells in the pathobiology of cerebral blood vessels has been encompassed under the term “neurovascular unit (NVU).” This session brings together a series of papers on the role of the NVU in stroke and neurodegenerative diseases. The endothelial cell remains central to the NVU, but its function is regulated by input from adjacent pericytes, astrocytes, and neurons.1 The extracellular matrix and the matrix-degrading enzymes and inhibitors play a key role at the basal lamina and the cell surface in the regulation of cell signaling.2 Much has been learned about the function of astrocytes, which rapidly transduce information between the microenvironment and other brain cells and the macrophage-like pericytes in effecting changes at the cerebral capillary level. The presentations were arranged to emphasize recent advances in our understanding of the anatomy and physiology of the NVU (Lo), recent studies on the astrocytes (Nedergaard), and pericytes (Fisher). The final 2 presentations describe the role of extracellular matrix enzymes in amyloid metabolism as it relates to Alzheimer disease (Lee) and vascular cognitive impairment (Rosenberg). The goal of the session was to provide an overview on the role of the separate cell types composing the NVU and to show how they interact in acute and chronic cerebrovascular diseases.Transgenic …