Effects of picrotoxin and strychnine on fish retinal S-potentials: evidence for inhibitory control of depolarizing responses.
Simultaneous recording of the light evoked electrical signals from different classes of slow(S)-potential unit in the isolated fish retina established that picrotoxin, an antagonist of GABA, selectively suppresses the depolarizing component of C-type S-potentials. In contrast, equivalent concentrations of strychnine have no effect on S-potentials, but suppress a component of transient amacrine cell responses. On the basis of these and other experimental data [3,4] we propose a network diagram for the C-type S-potential units in the cyprinid fish retina. This network includes a GABA-ergic feed-back loop and is essentially similar to that proposed by Fuortes and Simon [5].
D000818:Animals; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000187:drug effects; D005399:Fishes; D010852:Picrotoxin / Q000494:pharmacology*; D012160:Retina / Q000187:drug effects / Q000502:physiology*; D013331:Strychnine / Q000494:pharmacology*
D010852:Picrotoxin; D013331:Strychnine