Figure 3.

Motor cortex input to Po and dorsal VPM. A, After iontophoretic injection of FluoroGold in the deep layers of the motor area, retrograde labeling was found in Po and in the intralaminar nuclei, but no backlabeled cells were present in the VPM itself. B, C, Pressure injection of BDA in the deep layers of the motor area (B) led to the anterograde labeling of a dense plexus of corticothalamic fibers in Po and intralaminar nuclei (C). The boxed area in C is enlarged in D, where one can see some axonal branches bearing boutons that invaded the dorsal VPM.