Pericyte

Pericytes (formerly called Rouget cells) are multi-functional mural cells of the microcirculation that wrap around the endothelial cells that line the capillaries throughout the body. Pericytes help in the maintainenance of homeostatic and hemostatic functions in the brain, where one of the organs is characterized with a higher pericyte coverage. A deficiency of pericytes in the central nervous system can cause increased permeability of the blood–brain barrier. The cells are also a key component of the neurovascular unit, which includes endothelium, astrocytes, and neurons. The morphology, distribution, density and molecular fingerprints ofpericytes vary between organs and vascular beds. They are associated with endothelial cell differentiation and multiplication, angiogenesis, survival of apoptotic signals and travel. They can also form direct connections with neighboring cells by forming peg and socket arrangements in which parts of the cells interlock, similar to the gears of a clock. They have been postulated to regulate capillary blood flow and the clearance and phagocytosis of cellular debris.