Related Experiment Video
Updated: Jun 12, 2026

Immunohistochemical and Calcium Imaging Methods in Wholemount Rat Retina
Published on: October 13, 2014
Excitatory amino acid receptors and transmitter release in the retina
M J Neal1, J R Cunningham, M A Shah
1Department of Pharmacology, United Medical and Dental Schools of Guy's and St Thomas's Hospitals (UMDS), St Thomas's Hospital, London SE1 7EH, England.
Abstract:
The effects of excitatory amino acids and some analogues on the release of GABA and ACh from amacrine cells were studied. The release of endogenous GABA from the isolated rat retina was measured by HPLC. When animals were pretreated with ?-vinyl-GABA (GVG), glutamate evoked a large efflux of GABA but kainate, quisqualate and N- methyl- d -aspartate (NMDA) were relatively ineffective. The glutamate evoked release of GABA was calcium dependent and was blocked by the antagonist, piperidine-dicarboxylic acid (PDA) indicating that activation of excitatory amino acid receptors was involved in the response. The release of [(3)H]ACh from the rabbit retina was strikingly increased by homocysteate and this effect was blocked by NMDA. Since NMDA also blocked the light evoked release of [(3)H]ACh but not the effects of exogenous glutamate or aspartate, it is possible that homocysteate may be a bipolar cell transmitter released onto cholinergic amacrine cells.
Related Concept Videos
Excitatory and Inhibitory Effects of Neurotransmitters
The Retina
G-Protein Gated Ion Channels
Sensory organs,...
Adrenergic Neurons: Neurotransmission
Synthesis: Catecholamine synthesis requires tyrosine, which is taken...
Classification of Neurotransmitters
Photoreceptors and Visual Pathways

