Localization of gamma-aminobutyric acid and glutamic acid decarboxylase in rhesus monkey retina.

Use of antisera directed against gamma-aminobutyric acid (GABA) and L-glutamic acid decarboxylase (GAD) in the retina of rhesus monkey reveals immunoreactivity in about one-third of amacrine and horizontal cells and in a subclass of cells situated within the ganglion cell layer. Within the inner plexiform layer neuronal processes form 3 heavily immunoreactive bands which alternate with two lightly reactive bands. Further, a dense narrow band of staining was observed in the scleral half of the outer plexiform layer. Müller cells and their processes are stained with anti-GABA but not with anti-GAD, suggesting that these glial cells take up, but do not synthesize GABA.