PT  - JOURNAL ARTICLE
AU  - Andrew R. Brown
AU  - G. Campbell Teskey
TI  - Motor Cortex Is Functionally Organized as a Set of Spatially Distinct Representations for Complex Movements
AID  - 10.1523/JNEUROSCI.2500-14.2014
DP  - 2014 Oct 08
TA  - The Journal of Neuroscience
PG  - 13574--13585
VI  - 34
IP  - 41
4099  - http://www.jneurosci.org/content/34/41/13574.short
4100  - http://www.jneurosci.org/content/34/41/13574.full
SO  - J. Neurosci.2014 Oct 08; 34
AB  - There is a long-standing debate regarding the functional organization of motor cortex. Intracortical microstimulation (ICMS) studies have provided two contrasting views depending on the duration of stimulation. In the rat, short-duration ICMS reveals two spatially distributed forelimb movement representations, the rostral forelimb area (RFA) and caudal forelimb area (CFA), eliciting identical movements. In contrast, long-duration ICMS reveals spatially distributed, complex, multijoint movement areas, with grasping found exclusively in the rostral area and reach-shaping movements of the arm located in the caudal area. To provide corroboration for which interpretation is correct, we selectively inactivated the RFA/grasp area during the performance of skilled forelimb behaviors using a reversible cortical cooling deactivation technique. A significant impairment of grasping in the single-pellet retrieval task and manipulations of pasta was observed during cooling deactivation of the RFA/grasp area, but not the CFA/arm area. Our results indicate a movement-based, rather than a muscle-based, functional organization of motor cortex, and provide evidence for a conserved homology of independent grasp and reach circuitry shared between primates and rats.