Use-dependent alterations of movement representations in primary motor cortex of adult squirrel monkeys

摘要: This study was undertaken to document plastic changes in the functional topography of primary motor cortex (M1) that are generated skill learning normal, intact primate. Intracortical microstimulation mapping techniques were used derive detailed maps representation movements distal forelimb zone M1 squirrel monkeys, before and after behavioral training on two different tasks differentially encouraged specific sets movements. After a small-object retrieval task, which required skilled use digits, their evoked-movement digit representations expanded, whereas wrist/forearm representational zones contracted. These progressive reversible. In second exercise, monkey pronated supinated forearm key (eyebolt)-turning task. this case, results show is alterable by throughout life an animal. studies also revealed there areal expansion dual-response representations, is, cortical sectors over stimulation produced about or more joints. Movement combinations frequently selectively magnified representations. close correspondence between performance electrophysiologically defined indicates neurophysiological correlate resides for at least several days acquisition. The finding cocontracting muscles behavior come be represented together argues that, as sensory cortices, temporal correlations drive emergent distributed