[Effect of GABA antagonists on the rat electroretinogram].
It has been shown that gamma-aminobutyric acid (GABA) is densely packed in the inner nuclear and plexiform layers in the rat retina, where it is mainly located within a subgroup of amacrine cells. This study examined the effects on the electroretinogram of GABA antagonists infused into the vitreous cavity of urethan-anesthetized rats. Infusions of the GABAA antagonist, bicuculline (0.1-10 mM, 3 microliters) significantly enhanced the b-wave amplitude and reduced the oscillatory potentials (OPs). Similar effects were also produced by infusions of the GABAB antagonist, phaclofen (10 mM, 3 microliters), although lower doses (0.1-1 mM, 3 microliters) had no effect. These results suggest that the actions of GABA, presumably released from amacrine cells, on both GABAA and GABAB receptors are involved in the normal generation of the b-wave and OPs.
Yoshida
K
K
Department of Ophthalmology, Kochi Medical School, Nankoku-shi, Japan.
Ueno
H
H
Saito
H
H
Tamai
A
A
D000818:Animals; D001418:Baclofen / Q000031:analogs & derivatives* / Q000494:pharmacology; D001640:Bicuculline / Q000494:pharmacology*; D004596:Electroretinography / Q000187:drug effects*; D018756:GABA Antagonists; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012160:Retina / Q000187:drug effects / Q000502:physiology
D018756:GABA Antagonists; C052329:phaclofen; D001418:Baclofen; D001640:Bicuculline