Dysfunctional cell-cell signaling in the neurovascular unit as a paradigm for central nervous system disease.

The fundamental premise of neuroprotection has historically focused on the prevention of neuronal death. However, despite tremendous advances in the molecular biology of intraneuronal mechanisms and pathways, a clinically effective neuroprotectant does not yet exist. This problem is especially clear for stroke, for which a large number of neuroprotection trials have failed. The concept of the neurovascular unit emphasizes that cell-cell signaling among the various neuronal, glial, and vascular compartments underlies the homeostasis of normal brain function. Conversely, dysfunctional signaling within the neurovascular unit should contribute to disease. This minireview surveys recent data that support this basic idea, with examples drawn from experimental models broadly relevant to stroke and neurodegeneration.