Odorants suppress voltage-gated currents in retinal horizontal cells in goldfish.
Odorants are known to suppress non-selectively voltage-gated currents in olfactory receptor cells. We found that odorants also suppress voltage-gated currents in neurons of outside of the olfactory system. Under voltage clamp, odorants such as amyl acetate, limonene, and acetophenone suppressed non-selectively voltage-gated currents (a Ca(2+) current, a delayed rectifier K(+) current, a fast transient K(+) current, and an anomalous rectifier K(+) current) in horizontal cells from the goldfish retina. An amyl acetate puff completely and immediately suppressed the Ca(2+) current (I(Ca)) and the delayed rectifier K(+) current induced by repetitive depolarizations, suggesting that amyl acetate is a closed-channel blocker. Odorants did not change significantly the activation curve of I(Ca), but made the slope of inactivation curve of I(Ca) gentler and shifted its half-inactivation voltage toward a negative voltage. These results are similar to the effects of odorants on voltage-gated currents in olfactory receptor cells. This suggests that odorants may suppress the voltage-gated currents in retinal horizontal cells by the same mechanism described in olfactory receptor cells.
Kawai
F
F
Department of Physiology, School of Medicine, Fujita Health University, 1-98 Dengakugakubo, Kutsukakechou, Toyoake, Aichi, Japan. fkawai@fujita-hu.ac.jp
Miyachi
E
E
D000098:Acetophenones / Q000494:pharmacology; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology; D053138:Cyclohexenes; D051668:Delayed Rectifier Potassium Channels; D006054:Goldfish; D066298:In Vitro Techniques; D015640:Ion Channel Gating; D007473:Ion Channels / Q000037:antagonists & inhibitors* / Q000502:physiology; D000077222:Limonene; D009812:Odorants; D018408:Patch-Clamp Techniques; D000439:Pentanols / Q000494:pharmacology; D026902:Potassium Channel Blockers; D015221:Potassium Channels / Q000502:physiology; D024642:Potassium Channels, Voltage-Gated; D012160:Retina / Q000166:cytology; D013729:Terpenes / Q000494:pharmacology
D000098:Acetophenones; D002121:Calcium Channel Blockers; D015220:Calcium Channels; D053138:Cyclohexenes; D051668:Delayed Rectifier Potassium Channels; D007473:Ion Channels; D000439:Pentanols; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D013729:Terpenes; C005716:amyl acetate; D000077222:Limonene; C038699:acetophenone