Dopamine modifies the balance of rod and cone inputs to horizontal cells of the Xenopus retina.
Dopamine (greater than or equal to 2 microM) increased the cone input and suppressed the rod input to axon-bearing horizontal cells of the Xenopus retina. Dopamine (10 microM) also depolarized the horizontal cell by about 9 mV. The D2-dopamine antagonists spiperone and metoclopramide had the opposite action to dopamine, whereas the D1-dopamine antagonist SCH 23390 was without effect. None of the agents tested modified the light-evoked responses of rods.
Witkovsky
P
P
Department of Ophthalmology, New York University Medical Center, NY 10016.
Stone
S
S
Besharse
J C
JC
D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D004298:Dopamine / Q000494:pharmacology*; D018492:Dopamine Antagonists; D005071:Evoked Potentials; D008564:Membrane Potentials / Q000187:drug effects; D008787:Metoclopramide / Q000494:pharmacology; D010775:Photic Stimulation; D010786:Photoreceptor Cells / Q000187:drug effects / Q000502:physiology*; D012160:Retina / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000502:physiology*; D013134:Spiperone / Q000494:pharmacology; D014981:Xenopus
D001552:Benzazepines; D018492:Dopamine Antagonists; D013134:Spiperone; D008787:Metoclopramide; D004298:Dopamine