Area V1 in macaque monkeys projects to multiple histochemically defined subdivisions of the inferior pulvinar complex

To investigate how visuotopic connections relate to chemoarchitecture of the inferior pulvinar (PI) complex in macaques, neuroanatomical tracers were placed into known portions of the visual representation in V1. Separate foci of label associated with both the upper and lower visual quadrants occupied neurochemically defined medial, central, lateral, and lateral-shell subdivisions, PIM, PIC, PIL, and PIL-S. Visuotopic connection patterns thus supported the concept of a larger PI that includes portions of three classically defined 'nuclei' [C. Gutierrez, A. Yaun and C.G. Cusick, Neurochemical subdivisions of the inferior pulvinar in macaque monkeys, J. Comp. Neurol., 363 (1995) 545-562.], and corresponds to the topographically organized V1 projection zone.