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. 1967 Sep;192(2):407–436. doi: 10.1113/jphysiol.1967.sp008307

A study of synaptic transmission in the absence of nerve impulses

B Katz, R Miledi
PMCID: PMC1365564  PMID: 4383089

Abstract

1. The axo-axonic giant synapse in the stellate ganglion of the squid has been used to study synaptic transmission.

2. When nerve impulses have been eliminated with tetrodotoxin, synaptic transfer of potential changes can still be obtained by applying brief depolarizing pulses to the presynaptic terminal.

3. Suitably matched pulses are as effective as the normal presynaptic spike in evoking post-synaptic potentials. The synaptic delay and the time course of the post-synaptic potential are very similar to that in the normal preparation.

4. The synaptic transfer (input/output) characteristic has been studied under different experimental conditions. With brief (1-2 msec) current pulses, post-synaptic response becomes detectable when the presynaptic depolarization exceeds about 30 mV. The post-synaptic potential increases about tenfold with 10 mV increments of presynaptic depolarization.

5. Calcium increases, magnesium reduces the slope of the synaptic transfer curve. The influences on this curve of (i) duration of the pulse, (ii) preceding level of membrane potential, (iii) position of recording electrode, (iv) rate of repetitive stimulation are described.

6. After loading the synaptic terminal with tetraethylammonium ions, large inside-positive potentials can be produced in the terminal and maintained for many milliseconds.

7. By raising the internal potential to a sufficiently high level, synaptic transfer becomes suppressed during the pulse, and the post-synaptic response is delayed until the end of the pulse.

8. This observation is in accord with a prediction of the `calcium hypothesis', viz. that inward movement of a positively charged Ca compound, or of the calcium ion itself, constitutes one of the essential links in the `electro-secretory' coupling process of the axon terminal.

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Selected References

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

  1. ARMSTRONG C. M., BINSTOCK L. ANOMALOUS RECTIFICATION IN THE SQUID GIANT AXON INJECTED WITH TETRAETHYLAMMONIUM CHLORIDE. J Gen Physiol. 1965 May;48:859–872. doi: 10.1085/jgp.48.5.859. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. BRYANT S. H. Transmission in squid giant synapses: the importance of oxygen supply and the effects of drugs. J Gen Physiol. 1958 Jan 20;41(3):473–484. doi: 10.1085/jgp.41.3.473. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. BULLOCK T. H., HAGIWARA S. Intracellular recording from the giant synapse of the squid. J Gen Physiol. 1957 Mar 20;40(4):565–577. doi: 10.1085/jgp.40.4.565. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Bloedel J. R., Gage P. W., Llinás R., Quastel D. M. Transmission across the squid giant synapse in the presence of tetrodotoxin. J Physiol. 1967 Jan;188(2):52P–53P. [PubMed] [Google Scholar]
  5. Bloedel J., Gage P. W., Llinás R., Quastel D. M. Transmitter release at the squid giant synapse in the presence of tetrodotoxin. Nature. 1966 Oct 1;212(5057):49–50. doi: 10.1038/212049a0. [DOI] [PubMed] [Google Scholar]
  6. DEL CASTILLO J., KATZ B. Biophysical aspects of neuro-muscular transmission. Prog Biophys Biophys Chem. 1956;6:121–170. [PubMed] [Google Scholar]
  7. DEL CASTILLO J., KATZ B. Changes in end-plate activity produced by presynaptic polarization. J Physiol. 1954 Jun 28;124(3):586–604. doi: 10.1113/jphysiol.1954.sp005131. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. FURSHPAN E. J., POTTER D. D. Transmission at the giant motor synapses of the crayfish. J Physiol. 1959 Mar 3;145(2):289–325. doi: 10.1113/jphysiol.1959.sp006143. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. HAGIWARA S., TASAKI I. A study on the mechanism of impulse transmission across the giant synapse of the squid. J Physiol. 1958 Aug 29;143(1):114–137. doi: 10.1113/jphysiol.1958.sp006048. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. HODGKIN A. L., HUXLEY A. F. A quantitative description of membrane current and its application to conduction and excitation in nerve. J Physiol. 1952 Aug;117(4):500–544. doi: 10.1113/jphysiol.1952.sp004764. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. HODGKIN A. L., KEYNES R. D. Movements of labelled calcium in squid giant axons. J Physiol. 1957 Sep 30;138(2):253–281. doi: 10.1113/jphysiol.1957.sp005850. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. HUBBARD J. I., SCHMIDT R. F. An electrophysiological investigation of mammalian motor nerve terminals. J Physiol. 1963 Apr;166:145–167. doi: 10.1113/jphysiol.1963.sp007096. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Hagiwara S., Nakajima S. Differences in Na and Ca spikes as examined by application of tetrodotoxin, procaine, and manganese ions. J Gen Physiol. 1966 Mar;49(4):793–806. doi: 10.1085/jgp.49.4.793. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. 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]
  15. KATZ B., MILEDI R. THE EFFECT OF CALCIUM ON ACETYLCHOLINE RELEASE FROM MOTOR NERVE TERMINALS. Proc R Soc Lond B Biol Sci. 1965 Feb 16;161:496–503. doi: 10.1098/rspb.1965.0017. [DOI] [PubMed] [Google Scholar]
  16. Kao C. Y. Tetrodotoxin, saxitoxin and their significance in the study of excitation phenomena. Pharmacol Rev. 1966 Jun;18(2):997–1049. [PubMed] [Google Scholar]
  17. Katz B., Miledi R. Release of acetylcholine from a nerve terminal by electric pulses of variable strength and duration. Nature. 1965 Sep 4;207(5001):1097–1098. doi: 10.1038/2071097a0. [DOI] [PubMed] [Google Scholar]
  18. Katz B., Miledi R. Tetrodotoxin and neuromuscular transmission. Proc R Soc Lond B Biol Sci. 1967 Jan 31;167(1006):8–22. doi: 10.1098/rspb.1967.0010. [DOI] [PubMed] [Google Scholar]
  19. Katz B., Miledi R. The release of acetylcholine from nerve endings by graded electric pulses. Proc R Soc Lond B Biol Sci. 1967 Jan 31;167(1006):23–38. doi: 10.1098/rspb.1967.0011. [DOI] [PubMed] [Google Scholar]
  20. Katz B., Miledi R. The timing of calcium action during neuromuscular transmission. J Physiol. 1967 Apr;189(3):535–544. doi: 10.1113/jphysiol.1967.sp008183. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Koketsu K., Nishi S. Effects of tetrodotoxin on the action potential in Na-free media. Life Sci. 1966 Dec;5(24):2341–2346. doi: 10.1016/0024-3205(66)90071-3. [DOI] [PubMed] [Google Scholar]
  22. Miledi R., Slater C. R. The action of calcium on neuronal synapses in the squid. J Physiol. 1966 May;184(2):473–498. doi: 10.1113/jphysiol.1966.sp007927. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Miledi R. Spontaneous synaptic potentials and quantal release of transmitter in the stellate ganglion of the squid. J Physiol. 1967 Sep;192(2):379–406. doi: 10.1113/jphysiol.1967.sp008306. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. NARAHASHI T., MOORE J. W., SCOTT W. R. TETRODOTOXIN BLOCKAGE OF SODIUM CONDUCTANCE INCREASE IN LOBSTER GIANT AXONS. J Gen Physiol. 1964 May;47:965–974. doi: 10.1085/jgp.47.5.965. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. TAKEUCHI A., TAKEUCHI N. Electrical changes in pre- and postsynaptic axons of the giant synapse of Loligo. J Gen Physiol. 1962 Jul;45:1181–1193. doi: 10.1085/jgp.45.6.1181. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. TASAKI I., HAGIWAR A. S. Demonstration of two stable potential states in the squid giant axon under tetraethylammonium chloride. J Gen Physiol. 1957 Jul 20;40(6):859–885. doi: 10.1085/jgp.40.6.859. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Watanabe A., Tasaki I., Singer I., Lerman L. Effects of tetrodotoxin on excitability of squid giant axons in sodium-free media. Science. 1967 Jan 6;155(3758):95–97. doi: 10.1126/science.155.3758.95. [DOI] [PubMed] [Google Scholar]

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