Altered outward K(+) currents in Drosophila larval neurons of memory mutants rutabaga and amnesiac.
K(+) currents in cultured Drosophila larval neurons have been classified into four categories according to their inactivation time constants, relative amplitude, and response to K(+) channel blockers 4-AP and tetraethylammonium. The percentage (65%) of neurons displaying K(+) currents which were reduced to 30% in amplitude by 5 mM cyclic adenosine monophosphate (cAMP) analog 8-bromo-cAMP in both Drosophila memory mutants rutabaga (rut) and amnesiac (amn) was significantly larger than that (50%) in wild type. This initial characterization provides evidence for altered K(+) currents in both rut and amn mutants. Arachidonic acid, a specifical inhibitor of Kv4 family (shal) K(+) channels, was found to inhibit K(+) currents in cultured Drosophila neurons, suggesting the presence of shal channels in these neurons.
Laboratory of Visual Information Processing, Department of Neurobiology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.
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Yu
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Feng
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Guo
D015761:4-Aminopyridine / Q000494:pharmacology; D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000262:Adenylyl Cyclases / Q000172:deficiency* / Q000235:genetics / Q000502:physiology; D000818:Animals; D016718:Arachidonic Acid / Q000494:pharmacology; D001921:Brain / Q000166:cytology / Q000254:growth & development; D002478:Cells, Cultured; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D017952:Ganglia, Invertebrate / Q000166:cytology / Q000254:growth & development; D019476:Insect Proteins / Q000235:genetics* / Q000502:physiology; D015640:Ion Channel Gating / Q000187:drug effects; D017136:Ion Transport / Q000187:drug effects; D007814:Larva; D008568:Memory / Q000502:physiology*; D009474:Neurons / Q000378:metabolism*; D009479:Neuropeptides / Q000172:deficiency* / Q000235:genetics / Q000502:physiology; D018408:Patch-Clamp Techniques; D011188:Potassium / Q000378:metabolism*; D026902:Potassium Channel Blockers; D015221:Potassium Channels / Q000378:metabolism* / Q000502:physiology; D024642:Potassium Channels, Voltage-Gated; D051672:Shal Potassium Channels; D019789:Tetraethylammonium / Q000494:pharmacology
D029721:Drosophila Proteins; D019476:Insect Proteins; D009479:Neuropeptides; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D051672:Shal Potassium Channels; C497024:Shal protein, Drosophila; C093565:amn protein, Drosophila; D015124:8-Bromo Cyclic Adenosine Monophosphate; D016718:Arachidonic Acid; D019789:Tetraethylammonium; D015761:4-Aminopyridine; D000262:Adenylyl Cyclases; D011188:Potassium