Posttetanic potentiation in strong and weak neuromuscular junctions: physiological differences caused by a differential Ca2+-influx.
We have sought physiological explanations for large differences in synaptic strength of different frog sartorius neuromuscular junctions, using the time course of posttetanic potentiation (PTP) of mEPP frequency as an indicator of the kinetics of Ca2+-metabolism in junctions of varying strengths. Results obtained in Ca2+ vs Ca2+-free/EGTA Ringers suggest that differences in the Ca2+-influx contribute to the physiological differences between strong and weak junctions.
D000818:Animals; D002118:Calcium / Q000502:physiology*; D066298:In Vitro Techniques; D007473:Ion Channels / Q000502:physiology; D007700:Kinetics; D008564:Membrane Potentials; D009045:Motor Endplate / Q000502:physiology; D009469:Neuromuscular Junction / Q000502:physiology*; D009473:Neuronal Plasticity; D011894:Rana pipiens; D009435:Synaptic Transmission
D007473:Ion Channels; D002118:Calcium