Seasonal changes in the properties of frog. End-plate channels.
The properties of the acetylcholine (ACh)-activated channel at the frog neuromuscular junction were studied using a two-microelectrode voltage clamp. The reversal potential was determined by interpolation of the ACh-induced current vs. voltage relation, while the single-channel conductance and the mean channel lifetime were calculated from fluctuation analysis of the mean ACh-induced end-plate current. Seasonal changes were observed in some of the measured parameters. While the reversal potential and the mean channel lifetime remained constant throughout the year, the single-channel conductance did not. The single-channel conductance was on the average 35% higher in the winter than in the summer. This effect could have survival value for hibernating frogs.
D000064:Acclimatization; D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology*; D009045:Motor Endplate / Q000187:drug effects / Q000502:physiology*; D009469:Neuromuscular Junction / Q000502:physiology*; D011894:Rana pipiens; D012621:Seasons
D007473:Ion Channels; D000109:Acetylcholine