Action and localization of gamma‐aminobutyric acid in the cat retina.

Abstract

The effects of iontophoretically applied GABA (gamma‐aminobutyric acid) and bicuculline on retinal ganglion cells were studied in the optically intact eye of the anaesthetized cat. GABA suppressed both the spontaneous activity and light‐evoked discharge of all retinal ganglion cells, regardless of their type and regardless of the visual stimulus used. Bicuculline antagonized the action of iontophoretically applied GABA. Bicuculline enhanced the spontaneous activity of on‐centre cells, but suppressed the spontaneous activity of most off‐centre cells. The light‐evoked response of on‐centre cells was increased by bicuculline. A more complicated picture emerged for off‐centre cells. Weak light responses were suppressed by bicuculline, but during strong light responses the initial transient phase of the response was dramatically enhanced. Amacrine cells of the inner nuclear layer and displaced amacrine cells of the ganglion cell layer were labelled, using glutamic acid decarboxylase (GAD) immunohistochemistry and [3H]muscimol uptake. GAD‐positive dendrites were found throughout the inner plexiform layer and no sign of dendritic stratification was detected.

Action and localization of glycine and taurine in the cat retina.

“…Transient peak responses always seem to be more resistant to drug action than tonic discharge (Sillito & Kemp, 1983). Our results with bicuculline application in off-centre cells (Bolz et al 1985) indicate that the same drug can dramatically increase the peak discharge and at the same time decrease the tonic part of the histogram. The comparison of strychnine and bicuculline action on the same off-centre cell in Fig.…”

The Classical Receptive Field Surround of Primate Parasol Ganglion Cells Is Mediated Primarily by a Non-GABAergic Pathway

“…These results are consistent with other studies that measured the receptive field of mammalian ganglion cells at photopic light levels. Frishman and Linsenmeier (1982) showed that picrotoxin had little effect on the surrounds of cat X and Y ganglion cells, and Bolz et al (1985) found that the application of neither GABA nor the GABA A receptor antagonist bicuculine affected the center-surround balance of cat ganglion cells. In a series of experiments, Daw and Ariel (1981) showed that picrotoxin did not eliminate the surround of any of the rabbit center-surround ganglion cell types.…”

GABA‐ergic control of visual perception in healthy volunteers: effects of midazolam, a benzodiazepine, on spatio‐temporal contrast sensitivity.

“…Studies on the uptake of tritiated GABA or muscimol [1,2] and immunocytochemistry with antibodies against glutamic acid decarboxylase (the GABA-synthesizing enzyme GAD) or against GABA [3,4] showed that, next to glycine, GABA is the predominant transmitter of amacrine cells in the mammalian retina. Amacrine cells of rat, cat and most animal species contain GAD.…”