Projections from the primary somatosensory cortex to basal ganglia and thalamus in the monkey.

Radioactive amino acids were injected into the postcentral cortex (areas 3, 1 and 2) in 6 monkeys (Macaca fascicularis). Fibers were traced to the ipsilateral putamen, to Olszewski's n. ventralis posterior lateralis pars caudalis, n. ventralis posterior medialis and inferior, to n. pulvinaris oralis, n. suprageniculatus and corpus geniculatum mediale pars magnocellularis. Furthermore, there were faint postcentral projections to claustrum, n. caudatus, n. centralis lateralis, n. centrum medianum, zona incerta and with respect to the postcentral face region to n. medialis dorsalis pars multiformis. Discrepancies with earlier findings were discussed and comparison was made between pre- and postcentral target regions.