title: Functional transmitters at retinal ganglion cells in the cat.
abstract: The effects of iontophoretically applied putative neurotransmitters and their antagonists on the responses of retinal ganglion cells were studied in the optically intact eye of anaesthetized cats. L-aspartate enhanced and a N-methyl-D-aspartate receptor blocker, 2-amino-5-phosphonovalerate, blocked visual excitations of "sustained" cells, whereas acetylcholine enhanced, and the nicotinic receptor blocker, dihydro-beta-erythroidine, blocked those of "transient" cells. GABA enhanced and bicuculline blocked inhibitions of on-centre cells, but glycine enhanced and strychnine blocked those of off-centre cells, whether the cells were "sustained" or "transient". The possibility that: (A) aspartate may be an excitatory transmitter at both "on-" and "off-sustained" cells and acetylcholine, at both "on-" and "off-transient" cells; (B) GABA may be an inhibitory transmitter for on-centre, and glycine, for off-centre cells, is discussed.
mesh_terms: D015763:2-Amino-5-phosphonovalerate; D000109:Acetylcholine / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001224:Aspartic Acid / Q000494:pharmacology; D001640:Bicuculline / Q000494:pharmacology; D002415:Cats; D004079:Dihydro-beta-Erythroidine / Q000494:pharmacology; D005998:Glycine / Q000494:pharmacology; D009433:Neural Inhibition; D018377:Neurotransmitter Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D012160:Retina / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000502:physiology*; D013331:Strychnine / Q000494:pharmacology; D014633:Valine / Q000031:analogs & derivatives / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
chemical_list: D018377:Neurotransmitter Agents; D004079:Dihydro-beta-Erythroidine; D001224:Aspartic Acid; D005680:gamma-Aminobutyric Acid; D015763:2-Amino-5-phosphonovalerate; D013331:Strychnine; D014633:Valine; D000109:Acetylcholine; D005998:Glycine; D001640:Bicuculline