Bulletin of Experimental Biology and Medicine

, Volume 137, Issue 4, pp 323–326 | Cite as

Effect of Blockers of Potential-Dependent and Calcium-Activated K+-Channels on Facilitation of Neuromuscular Transmission

  • M. A. Mukhamedyarov
  • M. G. Minlebaev
  • A. L. Zefirov


Rhythmic stimulation of nerve-muscle preparation of frog sternal muscle bathed in low-Ca2+ saline increased the release of neurotransmitter (facilitation) and modified the shape of extracellular response of nerve terminal (decreased phase III amplitude). Iberiotoxin and 4-aminopyridine modified the dynamics these processes. We conclude that inactivation of potential-dependent K+-channels and activation of calcium-dependent K+-channels in frog motor nerve terminals during rhythmic activity modulate Ca2+ influx into nerve terminals and contribute into facilitation of neurotransmitter secretion. The degree of these mechanisms depends on the rate of synaptic rhythmic activity.

neuromuscular synapse facilitation K+-channels iberiotoxin 4-aminopyridine residual calcium 


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Copyright information

© Plenum Publishing Corporation 2004

Authors and Affiliations

  • M. A. Mukhamedyarov
    • 1
  • M. G. Minlebaev
    • 1
  • A. L. Zefirov
    • 1
  1. 1.Department of Normal PhysiologyKazan State Medical UniversityUSA

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