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. 1976 Feb;255(1):81–104. doi: 10.1113/jphysiol.1976.sp011271

Analysis of pairs of individual Ia-E.P.S.P.S in single motoneurones.

L M Mendell, R Weiner
PMCID: PMC1309236  PMID: 176347

Abstract

1. Recordings of individual e.p.s.p.s evoked by the action of single medial gastrocnemius Ia fibres have been made from medial gastrocnemius motoneurones. In many motoneurones the action of two Ia fibres has been observed and the properties of the e.p.s.p.s compared. 2. For sixty-three pairs of averaged e.p.s.p.s, each from the same motoneurone, the ratio of half-widths was plotted against the ratio of rise times. These results were compared with theoretical values derived from the Rall compartmental model. It was found that variations in synaptic current time courses and differences in the termination of localized synaptic terminals were not sufficient to account for all the data. 3. Amplitude and rise time were inversely related but the correlation coefficient was very low. For pairs of e.p.s.p.s in the same motoneurone the e.p.s.p. with the fast rise time was larger than that with the slow rise time in forty-eight of sixty-three cases. 4. In a given motoneurone individual e.p.s.p.s evoked by the action of different Ia fibres did not vary greatly in amplitude. The ratio of peak amplitudes was less than 3 for 86% of the pairs of e.p.s.p.s examined, and the maximum was 4-8. 5. Amplitude histograms were constructed for individual e.p.s.p.s at thirty-three synapses. Twenty-two of them could be shown to satisfy the Poisson law. The others satisfied the binomial law or neither. 6. Within a given motoneurone the amplitude of an e.p.s.p. is closely related to the mean number of quanta released but not to the amplitude of the unit e.p.s.p. produced by the action of a single quantum of transmitter.

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Selected References

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  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 J. N., Crill W. E. Influence of dendritic location and membrane properties on the effectiveness of synapses on cat motoneurones. J Physiol. 1974 Jun;239(2):325–345. doi: 10.1113/jphysiol.1974.sp010571. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Blankenship J. E., Kuno M. Analysis of spontaneous subthreshold activity in spinal motoneurons of the cat. J Neurophysiol. 1968 Mar;31(2):195–209. doi: 10.1152/jn.1968.31.2.195. [DOI] [PubMed] [Google Scholar]
  4. Burke R. E. Composite nature of the monosynaptic excitatory postsynaptic potential. J Neurophysiol. 1967 Sep;30(5):1114–1137. doi: 10.1152/jn.1967.30.5.1114. [DOI] [PubMed] [Google Scholar]
  5. Burke R. E. Group Ia synaptic input to fast and slow twitch motor units of cat triceps surae. J Physiol. 1968 Jun;196(3):605–630. doi: 10.1113/jphysiol.1968.sp008526. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Burke R. E., Nelson P. G. Synaptic activity in motoneurons during natural stimulation of muscle spindles. Science. 1966 Mar 4;151(3714):1088–1091. doi: 10.1126/science.151.3714.1088. [DOI] [PubMed] [Google Scholar]
  7. 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]
  8. FADIGA E., BROOKHART J. M. Monosynaptic activation of different portions of the motor neuron membrane. Am J Physiol. 1960 Apr;198:693–703. doi: 10.1152/ajplegacy.1960.198.4.693. [DOI] [PubMed] [Google Scholar]
  9. FATT P. Sequence of events in synaptic activation of a motoneurone. J Neurophysiol. 1957 Jan;20(1):61–80. doi: 10.1152/jn.1957.20.1.61. [DOI] [PubMed] [Google Scholar]
  10. Iansek R., Redman S. J. An analysis of the cable properties of spinal motoneurones using a brief intracellular current pulse. J Physiol. 1973 Nov;234(3):613–636. doi: 10.1113/jphysiol.1973.sp010364. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Iansek R., Redman S. J. The amplitude, time course and charge of unitary excitatory post-synaptic potentials evoked in spinal motoneurone dendrites. J Physiol. 1973 Nov;234(3):665–688. doi: 10.1113/jphysiol.1973.sp010366. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Iles J. F. Proceedings: Demonstration of afferent terminations in the cat spinal cord. J Physiol. 1973 Oct;234(2):22P–24P. [PubMed] [Google Scholar]
  13. Jack J. J., Miller S., Porter R., Redman S. J. The time course of minimal excitory post-synaptic potentials evoked in spinal motoneurones by group Ia afferent fibres. J Physiol. 1971 Jun;215(2):353–380. doi: 10.1113/jphysiol.1971.sp009474. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Jack J. J., Redman S. J. An electrical description of the motoneurone, and its application to the analysis of synaptic potentials. J Physiol. 1971 Jun;215(2):321–352. doi: 10.1113/jphysiol.1971.sp009473. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. 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]
  16. KATZ B., MILEDI R. A STUDY OF SPONTANEOUS MINIATURE POTENTIALS IN SPINAL MOTONEURONES. J Physiol. 1963 Sep;168:389–422. doi: 10.1113/jphysiol.1963.sp007199. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. KUNO M. QUANTAL COMPONENTS OF EXCITATORY SYNAPTIC POTENTIALS IN SPINAL MOTONEURONES. J Physiol. 1964 Dec;175:81–99. doi: 10.1113/jphysiol.1964.sp007504. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Katz B., Miledi R. The binding of acetylcholine to receptors and its removal from the synaptic cleft. J Physiol. 1973 Jun;231(3):549–574. doi: 10.1113/jphysiol.1973.sp010248. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Kirkwood P. A., Sears T. A. Monosynaptic excitation of motoneurones from secondary endings of muscle spindles. Nature. 1974 Nov 15;252(5480):243–244. doi: 10.1038/252243a0. [DOI] [PubMed] [Google Scholar]
  20. Klee M. R., Pierau F. K., Faber D. S. Temperature effects on resting potential and spike parameters of cat motoneurons. Exp Brain Res. 1974 Mar 29;19(5):478–492. doi: 10.1007/BF00236112. [DOI] [PubMed] [Google Scholar]
  21. Kuno M., Miyahara J. T. Analysis of synaptic efficacy in spinal motoneurones from 'quantum' aspects. J Physiol. 1969 Apr;201(2):479–493. doi: 10.1113/jphysiol.1969.sp008768. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Kuno M., Miyahara J. T. Factors responsible for multiple discharge of neurons in Clarke's column. J Neurophysiol. 1968 Jul;31(4):624–638. doi: 10.1152/jn.1968.31.4.624. [DOI] [PubMed] [Google Scholar]
  23. Kuno M., Miyahara J. T. Non-linear summation of unit synaptic potentials in spinal motoneurones of the cat. J Physiol. 1969 Apr;201(2):465–477. doi: 10.1113/jphysiol.1969.sp008767. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Kuno M., Muñoz-Martinez E. J., Randić M. Synaptic action on Clarke's column neurones in relation to afferent terminal size. J Physiol. 1973 Jan;228(2):343–360. doi: 10.1113/jphysiol.1973.sp010090. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Kuno M. Quantum aspects of central and ganglionic synaptic transmission in vertebrates. Physiol Rev. 1971 Oct;51(4):647–678. doi: 10.1152/physrev.1971.51.4.647. [DOI] [PubMed] [Google Scholar]
  26. MARTIN A. R., PILAR G. QUANTAL COMPONENTS OF THE SYNAPTIC POTENTIAL IN THE CILIARY GANGLION OF THE CHICK. J Physiol. 1964 Dec;175:1–16. doi: 10.1113/jphysiol.1964.sp007499. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Magleby K. L., Terrar D. A. Factors affecting the time course of decay of end-plate currents: a possible cooperative action of acetylcholine on receptors at the frog neuromuscular junction. J Physiol. 1975 Jan;244(2):467–495. doi: 10.1113/jphysiol.1975.sp010808. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Matthews B. H. Nerve endings in mammalian muscle. J Physiol. 1933 Apr 13;78(1):1–53. doi: 10.1113/jphysiol.1933.sp002984. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. McLachlan E. M. An analysis of the release of acetylcholine from preganglionic nerve terminals. J Physiol. 1975 Feb;245(2):447–466. doi: 10.1113/jphysiol.1975.sp010855. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. McLaughlin B. J. Dorsal root projections to the motor nuclei in the cat spinal cord. J Comp Neurol. 1972 Apr;144(4):461–474. doi: 10.1002/cne.901440405. [DOI] [PubMed] [Google Scholar]
  31. Mendell L. M., Henneman E. Terminals of single Ia fibers: distribution within a pool of 300 homonymous motor neurons. Science. 1968 Apr 5;160(3823):96–98. doi: 10.1126/science.160.3823.96. [DOI] [PubMed] [Google Scholar]
  32. Mendell L. M., Henneman E. Terminals of single Ia fibers: location, density, and distribution within a pool of 300 homonymous motoneurons. J Neurophysiol. 1971 Jan;34(1):171–187. doi: 10.1152/jn.1971.34.1.171. [DOI] [PubMed] [Google Scholar]
  33. Rall W., Burke R. E., Smith T. G., Nelson P. G., Frank K. Dendritic location of synapses and possible mechanisms for the monosynaptic EPSP in motoneurons. J Neurophysiol. 1967 Sep;30(5):1169–1193. doi: 10.1152/jn.1967.30.5.1169. [DOI] [PubMed] [Google Scholar]
  34. Rall W. Distinguishing theoretical synaptic potentials computed for different soma-dendritic distributions of synaptic input. J Neurophysiol. 1967 Sep;30(5):1138–1168. doi: 10.1152/jn.1967.30.5.1138. [DOI] [PubMed] [Google Scholar]
  35. Redman S. J. The attenuation of passively propagating dendritic potentials in a motoneurone cable model. J Physiol. 1973 Nov;234(3):637–664. doi: 10.1113/jphysiol.1973.sp010365. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. Rinzel J., Rall W. Transient response in a dendritic neuron model for current injected at one branch. Biophys J. 1974 Oct;14(10):759–790. doi: 10.1016/S0006-3495(74)85948-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Rudomin P., Burke R. E., Núez R., Madrid J., Dutton H. Control by Preynaptic Correlation: a mechanism affecting information transmission from Ia fibers to motoneurons. J Neurophysiol. 1975 Mar;38(2):267–284. doi: 10.1152/jn.1975.38.2.267. [DOI] [PubMed] [Google Scholar]
  38. Tsukahara N., Kosaka K. The mode of cerebral activation of red nucleus neurons. Experientia. 1966 Mar 15;22(3):193–194. doi: 10.1007/BF01897733. [DOI] [PubMed] [Google Scholar]
  39. Weakly J. N. Effect of barbiturates on 'quantal' synaptic transmission in spinal motoneurones. J Physiol. 1969 Sep;204(1):63–77. doi: 10.1113/jphysiol.1969.sp008898. [DOI] [PMC free article] [PubMed] [Google Scholar]

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