title: APB (2-amino-4-phosphonobutyric acid) activates a chloride conductance in ganglion cells isolated from newt retina.
abstract: In vertebrate retinae, APB (2-amino-4-phosphonobutyrate) selectively activates glutamate receptors of ON-bipolar cells. Thus, APB has been used as a pharmacological tool for studying the functional retinal circuitry and the inputs to higher-order pathways of the visual centres. Direct action of APB on ganglion cells has not previously been demonstrated. We now report, using whole-cell patch-clamp recordings, that APB has a direct inhibitory effect on ganglion cells isolated from newt retina. APB-induced currents were dependent upon the intracellular Cl- concentration. Their reversal potential values agreed with theoretical values of Cl- equilibrium potential. Strychnine, a glycine receptor blocker, inhibited the APB response. These results may suggest that APB activates the Cl- channels of ganglion cells through glycine receptors.
authors.affiliation: University of Tsukuba, Institute of Biological Sciences, Ibaraki, Japan.
authors.forename: C
authors.initials: C
authors.lastname: Chiba
authors.forename: T
authors.initials: T
authors.lastname: Saito
mesh_terms: D000613:Aminobutyrates / Q000494:pharmacology*; D000818:Animals; D002469:Cell Separation; D002712:Chlorides / Q000502:physiology*; D004553:Electric Conductivity; D018756:GABA Antagonists; D066298:In Vitro Techniques; D018009:Receptors, Glycine / Q000037:antagonists & inhibitors; D012165:Retinal Ganglion Cells / Q000187:drug effects*; D012455:Salamandridae
chemical_list: D000613:Aminobutyrates; D002712:Chlorides; D018756:GABA Antagonists; D018009:Receptors, Glycine; C012729:2-amino-4-phosphonobutyric acid