ATP-sensitive and Ca2+-activated K+ channel activities in the rat locus coeruleus neurons during metabolic inhibition.
Locus coeruleus (LC) is the significant nucleus for consciousness and it is sensitive to metabolic inhibition. We investigated the effects of a metabolic inhibitor sodium cyanide (NaCN) on the rat dissociated LC neurons using nystatin-perforated patch recordings. Under voltage-clamp (VH=-40 mV), application of NaCN evoked outward currents composed of ATP-sensitive and Ca2+-dependent K+ channel currents (IKATP and IKCa2+). Onset of IKATP was faster than that of IKCa2+. Prolonged application of NaCN brought IKATP rundown but not IKCa2+ rundown. Okadaic acid prevented IKATP rundown, indicating that KATP channels are deactivated by dephosphorylation with protein phosphatase.
D000255:Adenosine Triphosphate / Q000502:physiology*; D000818:Animals; D002118:Calcium / Q000502:physiology*; D018999:Charybdotoxin / Q000494:pharmacology; D004734:Energy Metabolism / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007004:Hypoglycemic Agents / Q000494:pharmacology; D008125:Locus Coeruleus / Q000166:cytology* / Q000502:physiology; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation; D015221:Potassium Channels / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012966:Sodium Cyanide / Q000494:pharmacology; D014044:Tolbutamide / Q000494:pharmacology