Role of adaptive plasticity in recovery of function after damage to motor cortex

Based upon neurophysiologic, neuroanatomic, and neuroimaging studies conduc ted over the past two decades, the cerebral cortex can now be viewed as fun ctionally and structurally dynamic. More specifically, the functional topog raphy of the motor cortex (commonly called the motor homunculus or motor ma p), can be modified by a variety of experimental manipulations, including p eripheral or central injury, electrical stimulation, pharmacologic treatmen t, and behavioral experience. The specific types of behavioral experiences that induce long-term plasticity in motor maps appear to be limited to thos e that entail the development of new motor skills. Moreover, recent evidenc e demonstrates that functional alterations in motor cortex organization are accompanied by changes in dendritic and synaptic structure, as well as alt erations in the regulation of cortical neurotransmitter systems. These find ings have strong clinical relevance as it has recently been shown that afte r injury to the motor cortex, as might occur in stroke, post-injury behavio ral experience may play an adaptive role in modifying the functional organi zation of the remaining, intact cortical tissue. (C) 2001 John Wiley & Sons , Inc.