PATTERNING AND SPECIFICATION OF THE CEREBRAL-CORTEX

Regionalization of the cerebral cortex occurs during development by th e formation of anatomically and functionally discrete areas of the bra in. Descriptive evidence based on expression of molecules and structur al features suggests that an early parcelation of the cerebral wall ma y occur during fetal development. Experimental strategies using tissue transplants and cell culture models have explored the nature of the t iming of areal specification. New signaling systems displaying the sen sitivity of precursor cells to environmental cues that define the fate of neurons destined for specific areas of the cortex have been discov ered. Studies in the field now suggest mechanisms of regulating cell p henotype in the cortex that are common to all parts of the neuraxis.