Immunocytochemical localization of the amino acid neurotransmitters in the chicken retina

Abstract

Postembedding immunocytochemistry was used to determine the cellular localization of the amino acid neurotransmitters glutamate, aspartate, gamma‐aminobutyric acid (GABA), and glycine in the avian retina. The through retinal pathway was glutamatergic, with all photoreceptors, bipolar cells, and ganglion cells being immunoreactive for glutamate. Bipolar cells displayed the highest level of glutamate immunoreactivity, with the cell bodies terminating just below the middle of the inner nuclear layer. All lateral elements, horizontal cells, amacrine cells, and interplexiform cells were immunoreactive for glycine or GABA. The GABAergic neurons consisted of two classes of horizontal cells and amac..