title: Effects of gamma-aminobutyric acid on cones and bipolar cells of the tiger salamander retina.
abstract: The gamma-aminobutyric acid (GABA) system in the tiger salamander retina was studied using autoradiographic and electrophysiological techniques. A high-affinity uptake mechanism for GABA has been localized in about 60% of the horizontal cells and about 30% of the amacrine cells. Effects of exogeneously applied GABA on the membrane conductance of cones and hyperpolarizing bipolar cells (HBC) were examined using the two electrode current-clamp technique in the living retinal slices. In both cell types, 1 mM of GABA caused a conductance increase. In perfused eyecups, 2 mM of GABA selectivity abolished the surround response of the HBC and left the center response unchanged. These results are consistent with the notion that a population of horizontal cells and a population of amacrine cells in the salamander retina may use GABA as their neurotransmitter.
mesh_terms: D000557:Ambystoma; D000818:Animals; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000187:drug effects; D010786:Photoreceptor Cells / Q000187:drug effects*; D012160:Retina / Q000187:drug effects* / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D005680:gamma-Aminobutyric Acid