Corticostriate projections from area 6 in the raccoon.

Corticostriate projections from area 6 in the raccoon were studied using the autoradiographic tracing method. Following injections of tritiated amino acids into two different cytoarchitectonic subdivisions of area 6, widespread and dense anterograde label was found in both the ipsilateral and contralateral caudate nucleus and putamen. The densest label was located adjacent to the internal capsule in the lateral part of the head of the caudate nucleus. This bilateral projection pattern from area 6 to the caudate nucleus and putamen is consistent with the hypothesis that the neostriatum maintains a close anatomical and functional relationship with area 6.