An analysis of inputs to ON-OFF amacrine cells in the carp retina with kynurenic acid.
Amacrine cell inputs were studied in the carp retina. Responses to light of bipolar and amacrine cells in off-pathways were suppressed by 0.5 mM kynurenic acid (Kyn), while those in on-pathways were not. In ON-OFF amacrine cells, the sustained potential level during illumination shifted in the depolarizing direction. The depolarizing response elicited in off-center bipolar cells by transretinal current was also suppressed, but those elicited in amacrine cells were not. The results indicated that off-pathways are selectively suppressed by 0.5 mM Kyn at the level of receptor-bipolar synapses and demonstrated that sustained levels of ON-OFF amacrine responses are determined by a balance of inputs from on- and off-center bipolar cells.
Fujimoto
M
M
Department of Physiology, St. Marianna University School of Medicine, Kawasaki, Japan.
Toyoda
J
J
D000818:Animals; D002347:Carps / Q000502:physiology*; D066298:In Vitro Techniques; D007736:Kynurenic Acid / Q000494:pharmacology*; D012160:Retina / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects
D007736:Kynurenic Acid