Functional Reorganization of the Rat Motor Cortex Following Motor Skill Learning

TLDR

Motor skill learning can reorganize cortical representations in rats, as demonstrated by changes in forelimb and hindlimb maps. Adult rats were trained for 10 days on either a skilled reaching task or a simple bar‑pressing task, after which microelectrode stimulation mapped forelimb and hindlimb cortical representations. Skilled‑reaching rats showed enlarged wrist and digit representations and reduced elbow/shoulder areas in the caudal forelimb cortex, with no changes in hindlimb or rostral forelimb maps, indicating motor skill learning induces cortical reorganization.

Abstract

Kleim, Jeffrey A., Scott Barbay, and Randolph J. Nudo. Functional reorganization of the rat motor cortex following motor skill learning. J. Neurophysiol. 80: 3321–3325, 1998. Adult rats were allocated to either a skilled or unskilled reaching condition (SRC and URC, respectively). SRC animals were trained for 10 days on a skilled reaching task while URC animals were trained on a simple bar pressing task. After training, microelectrode stimulation was used to derive high resolution maps of the forelimb and hindlimb representations within the motor cortex. In comparison with URC animals, SRC animals exhibited a significant increase in mean area of the wrist and digit representations but a decrease in elbow/shoulder representation within the caudal forelimb area. No between-group differences in areal representation were found in either the hindlimb or rostral forelimb areas. These results demonstrate that motor skill learning is associated with a reorganization of movement representations within the rodent motor cortex.