Retinal ganglion cells labelled from the pulvinar nucleus in macaque monkeys.
In order to study the distribution and morphological classes of retinal ganglion cells that can be retrogradely labelled from the pulvinar nucleus, we made two iontophoretic injections of horseradish peroxidase into the pulvinar in each hemisphere of five macaque monkeys. The retrogradely labelled ganglion cells projecting to or through the pulvinar nucleus were examined in retinal whole-mounts. They comprise all three major ganglion cell classes. Primate gamma cells formed the great majority of classifiable cells and, like the primate alpha cells that were found in much smaller numbers, they were already known to send axons to the superior colliculus and to the pretectal complex. In contrast, the primate beta cells were hitherto thought to project solely to the dorsal lateral geniculate nucleus. This primate beta cell projection to an extrageniculate target could account in part for the substantial number of primate beta cells that escape transneuronal retrograde retinal degeneration following striate cortical ablation, and might contribute to the residual visual sensitivity that survives destruction of striate cortex and the degeneration of the lateral geniculate nucleus.
Department of Experimental Psychology, University of Oxford, U.K.
A
A
Cowey
P
P
Stoerig
M
M
Bannister
D000818:Animals; D001369:Axons / Q000502:physiology; D005829:Geniculate Bodies / Q000166:cytology / Q000502:physiology; D006651:Histocytochemistry; D006735:Horseradish Peroxidase; D008252:Macaca fascicularis; D008297:Male; D010477:Perfusion; D012165:Retinal Ganglion Cells / Q000502:physiology*; D013787:Thalamic Nuclei / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology
D006735:Horseradish Peroxidase