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. 1979 Jun;291:425–441. doi: 10.1113/jphysiol.1979.sp012823

Inhibition of gamma motoneurone discharge by contraction of the homonymous muscle in the decerebrated cat.

P H Ellaway, P R Murphy, J R Trott
PMCID: PMC1280911  PMID: 480234

Abstract

1. The aim of this study has been to determine the autogenetic reflex effects of tendon organ stimulation upon gamma motoneurones in the decerebrated cat. 2. Tendon organs serving a muscle were excited by isometric twitch contractions of some motor units of that muscle. Contractions were elicited by electrical stimulation of the cut peripheral end of part of the ventral root supply, using a stimulus strength at or below maximum for alpha motoneurone axons. Afferent recordings in the same cats as were used to study reflexes of gamma motoneurones showed that tendon organs were powerfully excited during twitch contractions of their muscle. Early discharges were also elicited in both tendon organs and spindle primary afferents. 3. Background discharges of forty-seven triceps surae gamma motoneurones, ranging in axonal conduction velocity from 17 to 40 m/sec, were recorded from filaments of the muscle nerve. The initial response of twenty-two (47%) neurones to twitches of the triceps surae was inhibition of their discharge. The latency from time of stimulation of the ventral root ranged from 10 to 22 msec. The lowered probability of firing lasted an average of 25 msec and, occasionally, was seen as a short silent period. 4. The inhibition was reduced in duration by decreasing the resting muscle length so that less active tension was developed during contraction. 5. The inhibition was observed, in one instance, in the spinally transected decerebrated cat. 6. We argue the case that early discharges in tendon organ afferents give rise to the onset of inhibition and that tension dependent discharges of tendon organs contribute further inhibition of gamma motoneurones. 7. Sixteen gamma motoneurones were not affected by contraction but seventeen showed a period of facilitation. The facilitation could occur after a period of inhibition (eight neurones) or as the sole response to contraction. In either case facilitation occurred mainly during relaxation of the muscle and may, in part, be attributable to increased spindle primary ending firing at this time. 8. In discussion a comparision is made of the reflex effects of muscle afferent discharges on alpha and gamma motoneurones.

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Selected References

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

  1. Appelberg B., Johansson H., Kalistratov G. The influence of group II muscle afferents and low threshold skin afferents on dynamic fusimotor neurones to the triceps surae of the cat. Brain Res. 1977 Aug 19;132(1):153–158. doi: 10.1016/0006-8993(77)90713-2. [DOI] [PubMed] [Google Scholar]
  2. BROWN M. C., MATTHEWS P. B. The effect on a muscle twitch of the back-response of its motor nerve fibres. J Physiol. 1960 Feb;150:332–346. doi: 10.1113/jphysiol.1960.sp006391. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Burke D., Hagbarth K. E., Löfstedt L. Muscle spindle activity in man during shortening and lengthening contractions. J Physiol. 1978 Apr;277:131–142. doi: 10.1113/jphysiol.1978.sp012265. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. ECCLES J. C., ECCLES R. M., LUNDBERG A. Synaptic actions on motoneurones in relation to the two components of the group I muscle afferent volley. J Physiol. 1957 May 23;136(3):527–546. doi: 10.1113/jphysiol.1957.sp005778. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. ECCLES R. M., LUNDBERG A. Supraspinal control of interneurones mediating spinal reflexes. J Physiol. 1959 Oct;147:565–584. doi: 10.1113/jphysiol.1959.sp006262. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Ellaway P. H. An application of cumulative sum technique (cusums) to neurophysiology [proceedings]. J Physiol. 1977 Feb;265(1):1P–2P. [PMC free article] [PubMed] [Google Scholar]
  7. Ellaway P. H. Cumulative sum technique and its application to the analysis of peristimulus time histograms. Electroencephalogr Clin Neurophysiol. 1978 Aug;45(2):302–304. doi: 10.1016/0013-4694(78)90017-2. [DOI] [PubMed] [Google Scholar]
  8. Ellaway P. H. Recurrent inhibition of fusimotor neurones exhibiting background discharges in the decerebrate and the spinal cat. J Physiol. 1971 Jul;216(2):419–439. doi: 10.1113/jphysiol.1971.sp009533. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Ellaway P. H., Trott J. R. Autogenetic reflex action on to gamma motoneurones by stretch of triceps surae in the decerebrated cat. J Physiol. 1978 Mar;276:49–66. doi: 10.1113/jphysiol.1978.sp012219. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Ellaway P. H., Trott J. R. Reflex connections form muscle stretch receptors to their own fusimotor neurones. Prog Brain Res. 1976;44:113–122. doi: 10.1016/S0079-6123(08)60727-X. [DOI] [PubMed] [Google Scholar]
  11. Fromm C., Noth J. Reflex responses of gamma motoneurones to vibration of the muscle they innervate. J Physiol. 1976 Mar;256(1):117–136. doi: 10.1113/jphysiol.1976.sp011315. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. GRANIT R., POMPEIANO O., WALTMAN B. The early discharge of mammalian muscle spindles at onset of contraction. J Physiol. 1959 Sep 2;147:399–418. doi: 10.1113/jphysiol.1959.sp006251. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. GRANIT R., VAN DERMEULEN J. P. The pause during contraction in the discharge of the spindle afferents from primary end organs in cat extensor muscles. Acta Physiol Scand. 1962 Jun-Jul;55:231–244. doi: 10.1111/j.1748-1716.1962.tb02436.x. [DOI] [PubMed] [Google Scholar]
  14. Granit R., Kellerth J. O., Szumski A. J. Intracellular autogenetic effects of muscular contration on extensor motoneurones. The silent period. J Physiol. 1966 Feb;182(3):484–503. doi: 10.1113/jphysiol.1966.sp007833. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Green D. G., Kellerth J. O. Intracellular autogenetic and synergistic effects of muscular contraction on flexor motoneurones. J Physiol. 1967 Nov;193(1):73–94. doi: 10.1113/jphysiol.1967.sp008344. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Grillner S., Hongo T., Lund S. Descending monosynaptic and reflex control of gamma-motoneurones. Acta Physiol Scand. 1969 Apr;75(4):592–613. doi: 10.1111/j.1748-1716.1969.tb04414.x. [DOI] [PubMed] [Google Scholar]
  17. HUNT C. C., KUFFLER S. W. Stretch receptor discharges during muscle contraction. J Physiol. 1951 Apr;113(2-3):298–315. doi: 10.1113/jphysiol.1951.sp004573. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. HUNT C. C. Relation of function to diameter in afferent fibers of muscle nerves. J Gen Physiol. 1954 Sep 20;38(1):117–131. doi: 10.1085/jgp.38.1.117. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. HUNT C. C. The reflex activity of mammalian small-nerve fibres. J Physiol. 1951 Dec 28;115(4):456–469. doi: 10.1113/jphysiol.1951.sp004681. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. JANSEN J. K., MATTHEWS P. B. The central control of the dynamic response of muscle spindle receptors. J Physiol. 1962 May;161:357–378. doi: 10.1113/jphysiol.1962.sp006892. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. 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]
  22. Prochazka A., Westerman R. A., Ziccone S. P. Discharges of single hindlimb afferents in the freely moving cat. J Neurophysiol. 1976 Sep;39(5):1090–1104. doi: 10.1152/jn.1976.39.5.1090. [DOI] [PubMed] [Google Scholar]
  23. Stauffer E. K., Watt D. G., Taylor A., Reinking R. M., Stuart D. G. Analysis of muscle receptor connections by spike-triggered averaging. 2. Spindle group II afferents. J Neurophysiol. 1976 Nov;39(6):1393–1402. doi: 10.1152/jn.1976.39.6.1393. [DOI] [PubMed] [Google Scholar]
  24. Trott J. R. The effect of low amplitude muscle vibration on the discharge of fusimotor neurones in the decerebrate cat. J Physiol. 1976 Mar;255(3):635–649. doi: 10.1113/jphysiol.1976.sp011300. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Vallbo A. B. Discharge patterns in human muscle spindle afferents during isometric voluntary contractions. Acta Physiol Scand. 1970 Dec;80(4):552–566. doi: 10.1111/j.1748-1716.1970.tb04823.x. [DOI] [PubMed] [Google Scholar]

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