title: GABA receptors on horizontal cells in the goldfish retina.
abstract: We investigated the localization of GABA(A) and GABA(C) receptors in horizontal cells (HCs) and HC axon terminals (ATs) dissociated from goldfish retina, using whole-cell patch-clamping recordings. Applications of GABA on HCs induced two groups with inward currents at the holding potential of -50 mV: One was a sustained inward current in the H1 cell, with one type of HCAT (AT1), and the other was a transient inward current in other HC soma and HCAT (AT2). Co-application of GABA with bicuculline or SR95531, GABA(A) receptor antagonists, showed a non-blocking effect in the sustained current, but a blocking effect in the transient current. The sustained current was evoked by cis-4-aminocrotonic acid (CACA), a GABA(C) receptor agonist, while the transient current was not induced by CACA, but mimicked by muscimol, a GABA(A) receptor agonist. Both the sustained and transient currents were completely blocked by picrotoxin and not mimicked by baclofen, a GABA(B) receptor agonist. Thus H1 cell and AT1 have GABA(C) receptors, while H2, H3 cells and AT2 have GABA(A) receptors.
authors.affiliation: Physics and Biophysics Section, Department of Natural Sciences, College of Medicine, The Catholic University of Korea, 505 Banpo-dong Socho-gu, 137-701, Seoul, South Korea.
authors.forename: Sun-Sook
authors.initials: SS
authors.lastname: Paik
authors.forename: No Gi
authors.initials: NG
authors.lastname: Park
authors.forename: Sung-Jong
authors.initials: SJ
authors.lastname: Lee
authors.forename: Hye-Kyong
authors.initials: HK
authors.lastname: Han
authors.forename: Chang-Sub
authors.initials: CS
authors.lastname: Jung
authors.forename: Sun-Ho
authors.initials: SH
authors.lastname: Bai
authors.forename: Myung-Hoon
authors.initials: MH
authors.lastname: Chun
mesh_terms: D000818:Animals; D004594:Electrophysiology; D018755:GABA Agonists / Q000494:pharmacology; D018756:GABA Antagonists / Q000494:pharmacology; D006054:Goldfish; D018408:Patch-Clamp Techniques; D018079:Receptors, GABA / Q000502:physiology*; D012160:Retina / Q000166:cytology* / Q000502:physiology
chemical_list: D018755:GABA Agonists; D018756:GABA Antagonists; D018079:Receptors, GABA