Figure 7.

The distributions of cells labeled from a FR injection into the M1 grasp zone (blue) and a CTB injection into the PMv grasp zone (red). Cells labeled from the PMv injection completely obscure the PMv grasp zone; cross-reference the map in Figure 5B. The distributions of the two cell populations were similar in frontal cortex, but they were largely segregated in parietal cortex. The cortical borders of areas 3a, 3b, 1, and 2 were readily apparent from architectonic sections and are marked with solid black lines. The border separating M1 from premotor cortex was estimated from current thresholds for evoking movements with electrical stimulation and is marked with a dashed line. The lips of sulci are represented as solid gray lines, whereas the fundi are represented as dashed gray lines.