Angiogenesis and neuropathology.

Angiogenesis is crucial for both tissue development and tissue function and is an integral part of central nervous system embryogenesis and tumor grow th. Angiogenesis is extremely active during development, then remains stabl e during adulthood and decreases gradually during aging. Physiological proc esses and inflammation can transiently stimulate angiogenesis in adults. An giogenesis is modulated by a host signaling pathways, growth factors, growt h factor receptors, and membrane proteins associated with these receptors o r transcription factors. In disorders affecting the central nervous systems , as in those arising elsewhere in the body, angiogenesis can become inadeq uate, excessive, or qualitatively abnormal (dysplasia). These abnormalities can result in cerebral trophic disorders and in secondary remodeling. A fe w examples are given to illustrate various types of primary angiogenesis di sorders responsible for cerebral lesions and of secondary angiogenesis diso rders caused by an underlying cerebral disorder.