Fig. 3.

Retrograde CTB labeling of pallidothalamic-projecting neurons. CTB deposits were placed at the level of VA/VL thalamic nuclei in control, parkinsonian and dyskinetic monkeys. Following CTB injection in VA/VL nuclei (a), a large number of retrogradely labeled neurons were found throughout all territories of the GPi nucleus (b). Panel c shows an inset taken from panel B at a higher magnification. Scale bar is 3,000 μm in panel a, 1,000 μm in panel b, and 100 μm in panel c. ac anterior commissure, GPe external division of the globus pallidus, GPi internal division of the globus pallidus, ic internal capsule, SN substantia nigra, STN subthalamic nucleus, ot optic tract