scholarly journals Voltage-dependence of drug-induced conductance in frog neuromuscular junction.

1975 ◽  
Vol 72 (6) ◽  
pp. 2140-2144 ◽  
Author(s):  
E. Neher ◽  
B. Sakmann
1978 ◽  
Vol 71 (3) ◽  
pp. 285-299 ◽  
Author(s):  
B Scubon-Mulieri ◽  
R L Parsons

The influence of voltage on the time-course of desensitization onset and recovery has been studied at the frog neuromuscular junction. The activation-desensitization sequence was determined from carbachol-induced end-plate currents in potassium-depolarized fibers voltage-clamped either to -40 mV or +40 mV. The time-course of both desensitization onset and recovery developed exponentially, with onset occurring more rapidly than recovery. Desensitization onset was voltage dependent, the onset time constant being 8.3 +/- 1.3 s (11 fibers) at -40 mV and 19.3 +/- 3.4 s (15 fibers) at +40 mV. Recovery from desensitization was also influenced by voltage. The extent of recovery after 2 min was 80.4 +/- 6.3% in those fibers voltage-clamped to -40 mV and 57.4 +/- 3.6% in those fibers voltage-clamped to +40 mV. The voltage dependence of desenistization onset and recovery did not result from a difference in ability to control voltage at these two levels of membrane potential. These results demonstrate that in the potassium-depolarized preparation the processes controlling both desensitization onset and recovery of sensitivity from the desensitivity from the desensitized state are influenced by membrane voltage.


1996 ◽  
Vol 25 ◽  
pp. S36 ◽  
Author(s):  
M. Osanai ◽  
S. Suzuki ◽  
N. Suzuki ◽  
K. Kuba ◽  
H. Kijima

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