Cell biology of the neurovascular unit: implications for drug delivery across the blood-brain barrier

The central nervous system (CNS) neurovascular unit is a dynamic structure consisting of vascular endothelial cells, pericytes, and closely juxtaposed astrocytes and neurons. Contact and communication events between cells of the neurovascular unit regulate CNS development, modulate cerebral blood flow, and influence permeability properties of the blood-brain barrier. Dysregulation of proper neurovascular unit function is linked to many common human CNS pathologies, making it a target for a variety of neurotherapeutic interventions. Furthermore, manipulation of the neurovascular unit to enhance the delivery of drugs to the CNS is an active area of interest. In this review I summarize current data concerning the cell and molecular biology of the neurovascular unit. Additionally, I suggest how manipulation of novel protein components of the neurovascular unit may enhance delivery of neurotherapeutic drugs across the blood-brain barrier.