Rat's Nucleus of the Optic Tract and Retinal Ganglion Cells

Abstract

The nucleus of the optic tract (NOT) in the pretectum is the visuo-motor relay between the retina and preoculomotor structure in the pathway, and it conveys signals responsible for optokinetic nystagmus (OKN). However, what parts of the retina and what kinds of retinal ganglion cells project their fibers into the NOT are still unknown. In the present study, horseradish peroxidase conjugated with wheatgerm agglutinin was injected into the NOT in the rat. Labeled cells are diffusely demonstrated in the contralateral retina, whereas the labeled cells, only in the lower temporal crescent of the ipsilateral side. Ganglion cells were predominant in the range of small cells, i. e., W cells. However, medium-sized and large cells were also labeled. This suggests the participation of these cells in OKN.