The distribution of free amino acids in subdivision of rat and frog retinae obtained by a new technique.

A technique is described for splitting intact rat and frog retinae into laminae. These laminae have been examined histologically and the distribution of free amino acids in the laminae has been determined by the dansylation technique. In both rat and frog retinae, taurine was selectively concentrated in the photoreceptor cells and their processes. In the rat, glycine, glutamine and GABA were especially abundant in a lamina which contained the ganglion, inner plexiform and inner neuronal layers. High concentrations of GABA were also present in the outer plexiform layer. These results are discussed in terms of a possible transmitter function for these amino acids in the retina.