Figure 1.

Anatomical localization of recording sites in the three clinical states. A, Mapping of all sites recorded in the two hemispheres of the three monkeys, pooled on four frontal planes ranging from +3.3 to +6.3 mm from the PC. The border (dashed line) between the pallidonigral (open circles) and the cerebellar (filled circles) thalamus appears only on the last plane (right column). The pallidal thalamus is more lateral than the nigral thalamus, but the border between these two territories remains hard to delineate. B, Example of a calbindin-stained section with a highly visible trace of an electrode track (arrow) corresponding to the last recordings in the parkinsonian state. C, Enlarged view of the boxed section in B showing the border between the pallidal and cerebellar thalamus. Only the pallidal thalamus contains black-stained neurons. AN, Anterior nucleus; Cer, cerebellar thalamus; Cd, caudate nucleus; MD, mediodorsal nucleus; MT, mamillothalamic tract; Nig, nigral thalamus; Pal, pallidal thalamus; Ret, reticular nucleus.