ACUTE PLASTICITY IN THE HUMAN SOMATOSENSORY CORTEX FOLLOWING AMPUTATION

WE Studied a patient after amputation of an arm and found that in less than 24 h stimuli applied on the ipsilateral face were referred in a precise, topographically organized, modality-specific manner to distin ct points on the phantom. Functional magnetic resonance imaging (fMRI) performed one month later showed that brush-evoked activity in the br ain demonstrates objective signal changes which correlate with percept ual changes in the phantom hand. This finding in humans corresponds to the observations of immediate plasticity in cortical pathways describ ed in animals, including primates. The results suggest that reorganiza tion of sensory pathways occurs very soon after amputation in humans, potentially due to the unmasking of ordinarily silent inputs rather th an sprouting of new axon terminals. (C) 1998 Rapid Science Ltd.