[Why are pericytes important for brain functions?].

Pericytes are mural cells embedded in the basal membrane surrounding endothelial cells in capillary and small vessels (from precapillary arterioles to postcapillary venules). They exist with a high coverage ratio to endothelial cells in the brain and play crucial roles in the formation and maintenance of the blood-brain barrier and the control of blood flow through a close interaction with endothelial cells. Thus, intactness of pericyte is absolutely needed for neuronal/brain functions. Ageing, life-style diseases, hypoperfusion/ischemia, drugs, and genetic factors can primarily cause pericyte dysfunctions, thereby leading to the development or progression of various brain disorders, including cerebrovascular diseases. Because pericytes also play an important role in tissue repair after brain injuries, they have received much attention as a therapeutic target even from the standpoint of functional recovery.