Skip to main content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
J Physiol. 1997 Feb 15; 499(Pt 1): 267–282.
PMCID: PMC1159351
PMID: 9061654

Recurrent inhibition between motor nuclei innervating opposing wrist muscles in the human upper limb.

Abstract

1. Effects of conditioning motor volleys of increasing amplitude on antagonistic motor nuclei were tested at the wrist and elbow level in man. 2. The modifications of biceps, triceps, flexor carpi radialis (FCR) and extensor carpi radialis (ECR) motoneurone excitability were tested both in post-stimulus time histogram (PSTH) and rectified averaged EMG experiments. 3. Conditioning motor volleys were evoked in biceps, triceps, FCR and ECR muscles by electrical stimuli applied to the corresponding nerves. The intensity of the conditioning stimuli was systematically varied from an intensity just below motor threshold to one giving rise to a motor response equal to half of the maximal direct motor response (Mmax). 4. The effect of the injection of a cholinergist agonist, L-acetylcarnitine (L-Ac), on antagonistic conditioning motor volleys was tested for each motor nucleus. 5. Results obtained at the wrist and elbow level were strikingly different. Antagonistic motor volleys resulted in an early and long-lasting inhibition enhanced by L-Ac injection in wrist motor nuclei, while no modification was observed in elbow motor nuclei. 6. The characteristics of the early and long-lasting inhibition evoked in wrist motor nuclei by antagonistic motor volleys suggest that they are due to the activation of Renshaw cells by the conditioning motor volleys. 7. It is therefore concluded that these experiments provide further evidence that the interconnections between motoneurones, interneurones mediating reciprocal inhibition and Renshaw cells at the wrist level are different from those described elsewhere. Indeed, it has already been shown that the interneurones mediating reciprocal inhibition between FCR and ECR are not inhibited by Renshaw cells, and the results presented here suggest that FCR-coupled Renshaw cells inhibit ECR motoneurones and vice versa.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (2.7M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Images in this article

Click on the image to see a larger version.

Selected References

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

  • Aymard C, Chia L, Katz R, Lafitte C, Pénicaud A. Reciprocal inhibition between wrist flexors and extensors in man: a new set of interneurones? J Physiol. 1995 Aug 15;487(1):221–235. [PMC free article] [PubMed] [Google Scholar]
  • Baldissera F, Campadelli P, Cavallari P. Inhibition from radial group I afferents of H-reflex in wrist flexors. Electromyogr Clin Neurophysiol. 1983 Mar-Apr;23(3):187–193. [PubMed] [Google Scholar]
  • Binder MD, Kroin JS, Moore GP, Stuart DG. The response of Golgi tendon organs to single motor unit contractions. J Physiol. 1977 Oct;271(2):337–349. [PMC free article] [PubMed] [Google Scholar]
  • Cavallari P, Katz R. Pattern of projections of group I afferents from forearm muscles to motoneurones supplying biceps and triceps muscles in man. Exp Brain Res. 1989;78(3):465–478. [PubMed] [Google Scholar]
  • Day BL, Marsden CD, Obeso JA, Rothwell JC. Reciprocal inhibition between the muscles of the human forearm. J Physiol. 1984 Apr;349:519–534. [PMC free article] [PubMed] [Google Scholar]
  • Fetz EE, Gustafsson B. Relation between shapes of post-synaptic potentials and changes in firing probability of cat motoneurones. J Physiol. 1983 Aug;341:387–410. [PMC free article] [PubMed] [Google Scholar]
  • Fournier E, Meunier S, Pierrot-Deseilligny E, Shindo M. Evidence for interneuronally mediated Ia excitatory effects to human quadriceps motoneurones. J Physiol. 1986 Aug;377:143–169. [PMC free article] [PubMed] [Google Scholar]
  • Heckman CJ, Condon SM, Hutton RS, Enoka RM. Can Ib axons be selectively activated by electrical stimuli in human subjects? Exp Neurol. 1984 Dec;86(3):576–582. [PubMed] [Google Scholar]
  • Hultborn H, Jankowska E, Lindström S. Recurrent inhibition from motor axon collaterals of transmission in the Ia inhibitory pathway to motoneurones. J Physiol. 1971 Jul;215(3):591–612. [PMC free article] [PubMed] [Google Scholar]
  • Hultborn H, Lindström S, Wigström H. On the function of recurrent inhibition in the spinal cord. Exp Brain Res. 1979 Oct;37(2):399–403. [PubMed] [Google Scholar]
  • Hultborn H, Pierrot-Deseilligny E. Input-output relations in the pathway of recurrent inhibition to motoneurones in the cat. J Physiol. 1979 Dec;297(0):267–287. [PMC free article] [PubMed] [Google Scholar]
  • Katz R, Penicaud A, Rossi A. Reciprocal Ia inhibition between elbow flexors and extensors in the human. J Physiol. 1991 Jun;437:269–286. [PMC free article] [PubMed] [Google Scholar]
  • Malmgren K, Pierrot-Deseilligny E. Evidence for non-monosynaptic Ia excitation of human wrist flexor motoneurones, possibly via propriospinal neurones. J Physiol. 1988 Nov;405:747–764. [PMC free article] [PubMed] [Google Scholar]
  • Mao CC, Ashby P, Wang M, McCrea D. Synaptic connections from large muscle afferents to the motoneurons of various leg muscles in man. Exp Brain Res. 1984;56(2):341–350. [PubMed] [Google Scholar]
  • Marque P, Pierrot-Deseilligny E, Simonetta-Moreau M. Evidence for excitation of the human lower limb motoneurones by group II muscle afferents. Exp Brain Res. 1996 May;109(2):357–360. [PubMed] [Google Scholar]
  • Mazzocchio R, Rossi A. Further evidence for Renshaw inhibition in man. A combined electrophysiological and pharmacological approach. Neurosci Lett. 1989 Nov 20;106(1-2):131–136. [PubMed] [Google Scholar]
  • Meunier S, Penicaud A, Pierrot-Deseilligny E, Rossi A. Monosynaptic Ia excitation and recurrent inhibition from quadriceps to ankle flexors and extensors in man. J Physiol. 1990 Apr;423:661–675. [PMC free article] [PubMed] [Google Scholar]
  • Meunier S, Pierrot-Deseilligny E, Simonetta-Moreau M. Pattern of heteronymous recurrent inhibition in the human lower limb. Exp Brain Res. 1994;102(1):149–159. [PubMed] [Google Scholar]
  • Pierrot-Deseilligny E. Transmission of the cortical command for human voluntary movement through cervical propriospinal premotoneurons. Prog Neurobiol. 1996 Mar-Apr;48(4-5):489–517. [PubMed] [Google Scholar]
  • Rossi A, Decchi B, Zalaffi A, Mazzocchio R. Group Ia non-reciprocal inhibition from wrist extensor to flexor motoneurones in humans. Neurosci Lett. 1995 May 26;191(3):205–207. [PubMed] [Google Scholar]
  • Rossi A, Mazzocchio R. Presence of homonymous recurrent inhibition in motoneurones supplying different lower limb muscles in humans. Exp Brain Res. 1991;84(2):367–373. [PubMed] [Google Scholar]
  • Rossi A, Mazzocchio R, Parlanti S. Cortical projection of putative group Ib afferent fibres from the human forearm. Brain Res. 1991 Apr 26;547(1):62–68. [PubMed] [Google Scholar]
  • Rossi A, Zalaffi A, Decchi B. Heteronymous recurrent inhibition from gastrocnemius muscle to soleus motoneurones in humans. Neurosci Lett. 1994 Mar 14;169(1-2):141–144. [PubMed] [Google Scholar]
  • Stephens JA, Usherwood TP, Garnett R. Technique for studying synaptic connections of single motoneurones in man. Nature. 1976 Sep 23;263(5575):343–344. [PubMed] [Google Scholar]
  • WILSON VJ, BURGESS PR. Effects of antidromic conditioning on some motoneurons and interneurons. J Neurophysiol. 1962 Sep;25:636–650. [PubMed] [Google Scholar]

Articles from The Journal of Physiology are provided here courtesy of The Physiological Society

-