Quantum Hypothesis of Synaptic Transmission

  • A. Wernig
Part of the Journal of Neural Transmission book series (NEURAL SUPPL, volume 12)


The quantum hypothesis of transmitter release states that transmitter is released from presynaptic nerve terminals solely in transmitter packages (quanta). Experimental evidence for this is to be found in the occurrence of spontaneous depolarizations of the postsynaptic membrane (spont. e.p.p.s) with normally distributed amplitudes (unit potentials) (Fatt and Katz, 1952). Furthermore one can show that the postsynaptic membrane depolarization after the stimulation of the presynaptic nerve (evoked e.p.p.) is built up from single unit depolarizations (del Castillo and Katz, 1954; Boyd and Martin, 1956). Convincing direct evidence for quantal release comes from experiments at low temperature where the release of transmitter is sufficiently dispersed in time, so that by recording synaptic activity with extracellular glass microelectrodes it is possible to count individual quanta as they are released following a nerve impulse (Katz and Miledi, 1965 b). In a large number of nerve impulses under constant conditions the number of quanta released per impulse fluctuates from trial to trial to give a certain release pattern (i.e. observed numbers of trials which released 0, 1, 2, 3 a.s.o. quanta in the series) so that transmitter release might be considered a statistical process.


Synaptic Transmission Synaptic Vesicle Neuromuscular Junction Transmitter Release Mean Amplitude 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Atwood, H. L., and G. D. Bittner: Matching of excitatory and inhibitory inputs to crustacean muscle fibers. J. Neurophysiol. 34, 157–170 (1971).PubMedGoogle Scholar
  2. Atwood, H. L., and H. S. Johnston: Neuromuscular synapses of a crab motor axon. J. exp. Zool. 167, 457–470 (1968).CrossRefGoogle Scholar
  3. Atwood, H. L., and I. Parnas: Synaptic transmission in crustacean muscles with dual motor innervation. Comp. Biochem. Physiol. 27, 381–404 (1968).CrossRefGoogle Scholar
  4. Auerbach, A. A., and M. V. L. Bennett: Chemically mediated transmission at a giant fiber synapse in the central nervous system of a vertebrate. J. gen. Physiol. 53, 183–210 (1969).PubMedCrossRefGoogle Scholar
  5. Baker, P. F., A. L. Hodgkin, and E. B. Ridgway: Depolarization and Ca entry in squid giant axons. J. Physiol. 218, 709–756 (1971).PubMedGoogle Scholar
  6. Birks, R., H. E. Huxley, and B. Katz: The fine structure of the neuro¬muscular junction of the frog. J. Physiol. 150, 134–144 (1960).PubMedGoogle Scholar
  7. Bittner, G. D.: Differentiation of nerve terminals in the crayfish opener muscle and its functional significance. J. gen. Physiol. 51, 731–758 (1968).PubMedCrossRefGoogle Scholar
  8. Bittner, G. Dand J. Harrison: A reconsideration of the Poisson hypothesis for transmitter release at the crayfish neuromuscular junction. J. Physiol. 206, 1–23 (1970).Google Scholar
  9. Bittner, G. D., and D. Kennedy: Quantitative aspects of transmitter release. J. cell. Biol. 47, 585–592 (1970).PubMedCrossRefGoogle Scholar
  10. Blackman, J. G., B. L. Ginsborg, and C. Ray: On the quantal release of the transmitter at a sympathetic synapse. J. Physiol. 167, 402–415 (1963).PubMedGoogle Scholar
  11. Blackman, J. G., and R. D. Purves: Intracellular recordings from ganglia of the thoracic sympathetic chain of the guinea-pig. J. Physiol. 203, 173 to 198 (1969).Google Scholar
  12. Boyd, J. A., and A. R. Martin: The end-plate potential in mammalian muscle. J. Physiol. 132, 74–91 (1956).PubMedGoogle Scholar
  13. Bracho, H., and R. K. Orkand: Effect of calcium on excitatory neuro¬muscular transmission in the crayfish. J. Physiol. 206, 61–71 (1970).PubMedGoogle Scholar
  14. Ceccarelli, B., W. P. Hurlbut, and A. Mauro: Turnover of transmitter and synaptic vesicles at the frog neuromuscular junction. J. cell Biol. 57, 499 to 524 (1973).Google Scholar
  15. Christensen, B. N., and A. R. Martin: Estimates of probability of transmitter release at the mammalian neuromuscular junction. J. Physiol. 210, 933 to 945 (1970).Google Scholar
  16. Couteaux, R., and M. Pecot-Dechavassine: Vesicules synaptiques et poches au niveau des “zones actives” de la jonction neuromusculaire. C.R. Acad. Sci. Paris 271, 2346–2349 (1970).Google Scholar
  17. Del Castillo, J., and B. Katz: Quantal components of the end-plate potential. J. Physiol. 124, 560–573 (1954).Google Scholar
  18. Del Castillo, J., and B. Katz: Localization of active spots within the neuro¬muscular junction of the frog. J. Physiol. 132, 630–649 (1956).Google Scholar
  19. Dudel,].: Potential changes in the crayfish motor nerve terminal during repetitive stimulation. Pfliigers Arch. ges. Physiol. 282, 323–337 (1965).Google Scholar
  20. Dudel,]., and S. W. Kuffler: Mechanism of facilitation at the crayfish neuro-muscular junction. J. Physiol. 155, 530–542 (1961).Google Scholar
  21. Elmqvist, D., and D. M. J. Quastel: Presynaptic action of hemicholinium at the neuromuscular junction. J. Physiol. 177, 463–482 (1965 a).Google Scholar
  22. Elmqvist, D., and D. M. J. Quastel: A quantitative study of end-plate potentials in isolated human muscle. J. Physiol. 178, 505–529 (1965 b).Google Scholar
  23. Fatt, P., and B. Katz: Spontaneous subthreshold activity at motor nerve endings. J. Physiol. 117, 109–128 (1952).PubMedGoogle Scholar
  24. Ginsborg, B.L.: The vesicle hypothesis for the release of acetylcholine. In: Excitatory Synaptic Mechanisms, Proceedings of the Fifth International Meeting of Neurobiologists Andersen, P., and /. K. S. Jansen). Oslo: Universtetsforlaget. 1970.Google Scholar
  25. Heuser, J. E., and T. S. Reese: Evidence for recycling of synaptic vesicle membrane during transmitter release at the frog neuromuscular junction. J. cell Biol. 57, 315–344 (1973).PubMedCrossRefGoogle Scholar
  26. Hubbard, J. I.: Mechanism of transmitter release. Progr. Biophys. Mol. Biol. 21, 33–124 (1970).CrossRefGoogle Scholar
  27. Ishii, Y. Matsumura, and T. Furukawa: Quantal nature of transmission at the synapse between hair cells and eighth nerve fibers. J. pan J. Physiol. 21, 79–89 (1971). Johnson, W., and A Wernig: The binomial nature of transmitter release at the crayfish neuromuscular junction. J. Physiol. 218, 757–767 (1971).Google Scholar
  28. Jones, S. F., and S. Kwanbunbumpen: The effects of nerve stimulation and hemicholinium on synaptic vesicles at the mammalian neuromuscular junction. J. Physiol. 207, 31–50 (1970).PubMedGoogle Scholar
  29. Katz, B.: The Release of Neural Transmitter Substances. Springfield, 111.: Thomas. 1969.Google Scholar
  30. Katz, B., and R. Miledi: The measurement of synaptic delay and the time course of acetylcholine release at the neuromuscular junction. Proc. R. Soc. B 161, 483–495 (1965 a). Katz, B., and R. Miledi: The effect of temperature on the synaptic delay at the neuromuscular junction. J. Physiol. 181, 656–670 (1965 b).Google Scholar
  31. Katz, B., and Miledi: The release of acetylcholine from nerve endings by graded electric pulses. Proc. R. Soc. B 167, 23–38 (1967 a).Google Scholar
  32. Katz, B., and R. Miledi: The timing of Ca action during neuromuscular transmission. J. Physiol. 189, 535–544 (1967 b).Google Scholar
  33. Katz, B., and R. Miledi: Tetrodotoxin and neuromuscular facilitation. J. Physiol. 195, 481–492 (1968).PubMedGoogle Scholar
  34. Kunoj M.: Quantum aspects of central and ganglionic synaptic transmission in vertebrates. Physiol. Rev. 51, 647–678 (1971).Google Scholar
  35. Kuno, Af., and J. N. Weakly: Quantal components of the inhibitory synaptic potential in spinal motoneurones of the cat. J. Physiol. 224, 287–303 (1972).Google Scholar
  36. Martin, A A further study of the statistical composition of the end-plate potential. J. Physiol. 130, 114–122 (1955).Google Scholar
  37. Martin, A. R.: Quantal nature of synaptic transmission. Physiol. Rev. 51–66 (1966).Google Scholar
  38. Takeuchi, A., and N. Takeuchi: Active phase of frog’s end-plate potential. J. Neurophysiol. 22, 395–411 (1959).PubMedGoogle Scholar
  39. Wernig, A.: Changes in statistical parameters during facilitation at the crayfish neuromuscular junction. J. Physiol. 226, 751–759 (1972 a).Google Scholar
  40. Wernig, A.: The effects of Calcium and Magnesium on statistical release parameters at the crayfish neuromuscular junction. J. Physiol. 226, 761 to 768 (1972 b).Google Scholar
  41. Wernig, A.: Calculations of statistical release parameters from intracellular recordings on frog neuromuscular junction. Pflügers Arch. ges. Physiol. 343, R 72 (1973).Google Scholar
  42. Zucker, R. S.: Changes in the statistics of transmitter release during facilita¬tion. J. Physiol. 229, 787–810 (1973).PubMedGoogle Scholar

Copyright information

© Springer-Verlag 1975

Authors and Affiliations

  • A. Wernig
    • 1
  1. 1.Pharmakologisches InstitutUniversität InnsbruckInnsbruckAustria

Personalised recommendations