Voltage- and transmitter-gated currents of all-amacrine cells in a slice preparation of the rat retina.
All-amacrine cells are crucial interneurons in the rod pathway of the mammalian retina. They receive input synapses from rod bipolar cells and make electrical output synapses into the ON-pathway and glycinergic chemical synapses into the OFF-pathway. Whole-cell currents from more than 50 voltage-clamped All-amacrine cells were recorded in a slice preparation of the rat retina. The recorded cells were identified by intracellular staining with Lucifer yellow. Spike-like potentials could be elicited upon depolarization by current injection. A voltage-activated, fast, TTX-sensitive, inward Na+ current was identified. A prominent outward K+ current could be suppressed by tetraethylammonium. GABA as well as glycine activated Cl- channels, which could be blocked by bicuculline and strychnine, respectively. Four agonists of excitatory amino acid receptors--kainate (KA), AMPA, 2-amino-4-phosphonobutyrate (APB), and NMDA--were tested. Inward currents at holding potentials of VH = -70 mV were found by application of KA and AMPA but not by application of APB and NMDA. These currents could be blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). ACh did not evoke any current responses.
Boos
R
R
Max-Planck-Institut für Hirnforschung, Frankfurt, Germany.
Schneider
H
H
Wässle
H
H
D015761:4-Aminopyridine / Q000494:pharmacology; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D000613:Aminobutyrates / Q000494:pharmacology; D000818:Animals; D003035:Cobalt / Q000494:pharmacology; D004594:Electrophysiology / Q000379:methods; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D005998:Glycine / Q000494:pharmacology; D007051:Ibotenic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D066298:In Vitro Techniques; D015640:Ion Channel Gating / Q000187:drug effects; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology*; D007608:Kainic Acid / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D016202:N-Methylaspartate / Q000494:pharmacology; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D017459:Receptors, Amino Acid / Q000187:drug effects / Q000502:physiology; D012160:Retina / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000502:physiology; D015222:Sodium Channels / Q000502:physiology; D013331:Strychnine / Q000494:pharmacology; D013569:Synapses / Q000187:drug effects / Q000502:physiology; D019789:Tetraethylammonium; D013757:Tetraethylammonium Compounds / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D000613:Aminobutyrates; D005971:Glutamates; D007473:Ion Channels; D015221:Potassium Channels; D011810:Quinoxalines; D017459:Receptors, Amino Acid; D015222:Sodium Channels; D013757:Tetraethylammonium Compounds; D007051:Ibotenic Acid; D003035:Cobalt; D018698:Glutamic Acid; D013779:Tetrodotoxin; D005680:gamma-Aminobutyric Acid; D016202:N-Methylaspartate; D019789:Tetraethylammonium; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D015761:4-Aminopyridine; C012729:2-amino-4-phosphonobutyric acid; D013331:Strychnine; D007608:Kainic Acid; D005998:Glycine