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. 1972 Dec;227(3):665–689. doi: 10.1113/jphysiol.1972.sp010053

Quantal independence and uniformity of presynaptic release kinetics at the frog neuromuscular junction

Ellen F Barrett, C F Stevens
PMCID: PMC1331281  PMID: 4405552

Abstract

1. Amplitude and latency fluctuations of the end-plate potential at the frog neuromuscular junction were studied simultaneously at low temperatures, using intracellular or focal extracellular recording techniques and average quantal contents between 0·5 and 3.

2. At the release rates studied, the evoked release of one quantum has in most cases no significant effect on the probability of subsequent quantal release to the same stimulus, confirming the mutual independence of quantal releases in this preparation.

3. An equation derived from Poisson's law was applied to a histogram of the latencies of the first quantum released on each of a series of trials, to predict the average quantal content of end-plate responses originating at various times after nerve stimulation. The shape of the predicted time distribution of quantal contents usually agreed closely with that of the experimentally observed time distribution of end-plate response amplitudes. This agreement demonstrates that both the amplitude and the latency fluctuations of the end-plate response result from one presynaptic stochastic process that is uniform in magnitude and time course after each stimulus.

4. Analysis of extracellular records from synaptic regions with a history of extensive activity often suggested the existence of depressive interaction among quantal releases, perhaps caused by depletion of the supply of releasable quanta.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. BOYD I. A., MARTIN A. R. The end-plate potential in mammalian muscle. J Physiol. 1956 Apr 27;132(1):74–91. doi: 10.1113/jphysiol.1956.sp005503. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Barrett E. F., Stevens C. F. The kinetics of transmitter release at the frog neuromuscular junction. J Physiol. 1972 Dec;227(3):691–708. doi: 10.1113/jphysiol.1972.sp010054. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Betz W. J. Depression of transmitter release at the neuromuscular junction of the frog. J Physiol. 1970 Mar;206(3):629–644. doi: 10.1113/jphysiol.1970.sp009034. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Christensen B. N., Martin A. R. Estimates of probability of transmitter release at the mammalian neuromuscular junction. J Physiol. 1970 Nov;210(4):933–945. doi: 10.1113/jphysiol.1970.sp009250. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. DEL CASTILLO J., KATZ B. Localization of active spots within the neuromuscular junction of the frog. J Physiol. 1956 Jun 28;132(3):630–649. doi: 10.1113/jphysiol.1956.sp005554. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. DEL CASTILLO J., KATZ B. Quantal components of the end-plate potential. J Physiol. 1954 Jun 28;124(3):560–573. doi: 10.1113/jphysiol.1954.sp005129. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. DEL CASTILLO J., KATZ B. Statistical factors involved in neuromuscular facilitation and depression. J Physiol. 1954 Jun 28;124(3):574–585. doi: 10.1113/jphysiol.1954.sp005130. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Dodge F. A., Jr, Miledi R., Rahamimoff R. Strontium and quantal release of transmitter at the neuromuscular junction. J Physiol. 1969 Jan;200(1):267–283. doi: 10.1113/jphysiol.1969.sp008692. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Dodge F. A., Jr, Rahamimoff R. Co-operative action a calcium ions in transmitter release at the neuromuscular junction. J Physiol. 1967 Nov;193(2):419–432. doi: 10.1113/jphysiol.1967.sp008367. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. FATT P., KATZ B. Spontaneous subthreshold activity at motor nerve endings. J Physiol. 1952 May;117(1):109–128. [PMC free article] [PubMed] [Google Scholar]
  11. Gage P. W., Hubbard J. I. Evidence for a Poisson distribution of miniature end-plate potentials and some implications. Nature. 1965 Oct 23;208(5008):395–396. doi: 10.1038/208395a0. [DOI] [PubMed] [Google Scholar]
  12. Johnson E. W., Wernig A. The binomial nature of transmitter release at the crayfish neuromuscular junction. J Physiol. 1971 Nov;218(3):757–767. doi: 10.1113/jphysiol.1971.sp009642. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. KATZ B., MILEDI R. PROPAGATION OF ELECTRIC ACTIVITY IN MOTOR NERVE TERMINALS. Proc R Soc Lond B Biol Sci. 1965 Feb 16;161:453–482. doi: 10.1098/rspb.1965.0015. [DOI] [PubMed] [Google Scholar]
  14. KATZ B., MILEDI R. THE MEASUREMENT OF SYNAPTIC DELAY, AND THE TIME COURSE OF ACETYLCHOLINE RELEASE AT THE NEUROMUSCULAR JUNCTION. Proc R Soc Lond B Biol Sci. 1965 Feb 16;161:483–495. doi: 10.1098/rspb.1965.0016. [DOI] [PubMed] [Google Scholar]
  15. Katz B., Miledi R. The effect of temperature on the synaptic delay at the neuromuscular junction. J Physiol. 1965 Dec;181(3):656–670. doi: 10.1113/jphysiol.1965.sp007790. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. LILEY A. W. An investigation of spontaneous activity at the neuromuscular junction of the rat. J Physiol. 1956 Jun 28;132(3):650–666. doi: 10.1113/jphysiol.1956.sp005555. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. MARTIN A. R. A further study of the statistical composition on the end-plate potential. J Physiol. 1955 Oct 28;130(1):114–122. doi: 10.1113/jphysiol.1955.sp005397. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Moran N., Rahamimoff R. Some statistical properties of neuromuscular facilitation. Isr J Med Sci. 1970 Mar-Apr;6(2):201–208. [PubMed] [Google Scholar]
  19. Rotshenker S., Rahamimoff R. Neuromuscular synapse: stochastic properties of spontaneous release of transmitter. Science. 1970 Nov 6;170(3958):648–649. doi: 10.1126/science.170.3958.648. [DOI] [PubMed] [Google Scholar]
  20. TAKEUCHI A. The long-lasting depression in neuromuscular transmission of frog. Jpn J Physiol. 1958 Jun 15;8(2):102–113. doi: 10.2170/jjphysiol.8.102. [DOI] [PubMed] [Google Scholar]

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