Functional reorganization of the rat motor cortex following motor skill learning

Adult rats were allocated to either a skilled or unskilled reaching conditi on (SRC and URC, respectively). SRC animals were trained for 10 days on a s killed reaching task while URC animals were trained on a simple bar pressin g task. After training, microelectrode stimulation was used to derive high resolution maps of the forelimb and hindlimb representations within the mot or cortex. In comparison with URC animals, SRC animals exhibited a signific ant increase in mean area of the wrist and digit representations but a decr ease in elbow/shoulder representation within the caudal forelimb area. No b etween-group differences in areal representation were found in either the h indlimb-or rostral forelimb areas. These results demonstrate that motor ski ll learning is associated with a reorganization of movement representations within the rodent motor cortex.