Cholinergic amacrine cells of the rabbit retina contain glutamate decarboxylase and gamma-aminobutyrate immunoreactivity.

Abstract

The transmitters acetylcholine and yaminobutyrate (GABA) play critical roles in the formation of receptive-field properties of retinal ganglion cells. In rabbit retina, cholinergic amacrine and displaced amacrine cells were identified by immunohistochemical staining for the enzyme choline acetyltransferase and by their avid accumulation of the fluorescent dye 4',6-diamidino-2-phenylindole. Several GABAimmunoreactive and glutamate decarboxylase-immunoreactive cell types, including a prominent population of small, round amacrine and displaced amacrine cells, were also identified. Double-label experiments demonstrated that all amacrine and displaced amacrine cells that prominently accumulate 4',6-diamidino-2-phenylindole contain GABA and glutamate decarboxylase immunoreactivity. However, not all GABA-immunoreactive cells accumulate this dye. Quantitative analysis of the ganglion cell layer of whole mount preparations of the retina showed that choline acetyltransferase-immunoreactive cells and the majority of GABA-immunoreactive cells have a small, round shape and similar cell density profiles that parallel that of displaced amacrine cells. These studies establish that cholinergic cells are a major subpopulation of GABA-immunoreactive amacrine and displaced amacrine cells. The role these cells have in the formation of ganglion cell receptive-field properties may be parsimoniously explained by an excitatory postsynaptic action mediated by acetylcholine and an inhibitory presynaptic action mediated by GABA.

Comparison of the ontogeny of the vesicular glutamate transporter 3 (VGLUT3) with VGLUT1 and VGLUT2 in the rat retina

“…It has been proposed by Johnson et al, [24] that VGLUT3 expressing amacrine cells release both inhibitory and excitatory neurotransmitters like starburst amacrine cells. Support for this hypothesis comes from studies in starburst amacrine cells showing that these cells contain acetylcholine in addition to GABA [6,49], and the released acetylcholine can function as an excitatory neurotransmitter on both nicotinic and muscarinic receptors in the inner retina [36]. In addition, amacrine cells in lower vertebrates have been found to contain high levels of glutamate [8,40,52], with glutamate immunoreactivity present throughout all cell compartments, similar to the pattern of expression for VGLUT3 (see Fig.…”

Cation–chloride cotransporters mediate neural computation in the retina

“…In the model, the Na-K-Cl and K-Cl cotransporters are located on the proximal and distal portions of the SAC dendrites, respectively. In addition, the SAC expresses GABA (21) and glutamate (22,23) receptors, which are located along the entire length of its dendrites, and releases GABA (24)(25)(26) from the distal tips of its dendrites (20,27,28) onto the DS ganglion cell. The glutamatergic bipolar cell and GABAergic amacrine cell that provide input to the SAC are not depicted in Fig.…”

Coexpression of vesicular glutamate transporters 1 and 2, glutamic acid decarboxylase and calretinin in rat entorhinal cortex

“…This brings us back to Dale's postulate. This ''dogma'' has been challenged before, first with the observation of choline acetyltransferase and GABA in amacrine cells in the retina (Brecha et al 1988), later by evidence that axon terminals in visual cortex contain both acetylcholine and GABA (Beaulieu and Somogyi 1991) and further by the finding that boutons in the deep cerebellar nuclei contain GABA as well as glycine (Chen and Hillman 1993). Neuropeptides coexist with neurotransmitters (e.g.…”