Experimental Brain Research

, Volume 81, Issue 1, pp 35–45 | Cite as

Sensitivity of monosynaptic test reflexes to facilitation and inhibition as a function of the test reflex size: a study in man and the cat

  • C. Crone
  • H. Hultborn
  • L. Mazières
  • C. Morin
  • J. Nielsen
  • E. Pierrot-Deseilligny
Article

Summary

In parallel experiments on humans and in the cat it was investigated how the sensitivity of monosynaptic test reflexes to facilitation and inhibition varies as a function of the size of the control test reflex itself. In man the monosynaptic reflex (the Hoffmann reflex) was evoked in either the soleus muscle (by stimulation of the tibial nerve) or the quadriceps muscle (by stimulation of the femoral nerve). In the decerebrate cat monosynaptic reflexes were recorded from the nerves to soleus and medial gastrocnemius muscles; they were evoked by stimulation of the proximal ends of the sectioned L7 and S1 dorsal roots. Various excitatory and inhibitory spinal reflex pathways were used for conditioning the test reflexes (e.g. monosynaptic Ia excitation, disynaptic reciprocal inhibition, cutaneous inhibition, recurrent inhibition, presynaptic inhibition of the Ia fibres mediating the test reflex). It was shown that the additional number of motoneurones recruited in a monosynaptic test reflex by a constant excitatory conditioning stimulus was very much dependent on the size of the test reflex itself. This dependency had the same characteristic pattern whatever the conditioning stimulus. With increasing size of the test reflex the number of additionally recruited motoneurones first increased, then reached a peak (or plateau) and finally decreased. A similar relation was also seen with inhibitory conditioning stimuli. The basic physiological factors responsible for these findings are discussed. Finally, the implications for the interpretation of experiments in man with the H-reflex technique are considered.

Key words

Spinal cord Spinal reflexes Monosynaptic reflex Motor control Man Cat 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Baldissera F, Hultborn H, Illert M (1981) Integration in spinal neuronal systems. In: Brooks VB (ed) Handbook of physiology, Sect 1. The nervous system, Vol 2. Motor control. American Physiological Society, Bethesda MD, pp 509–595Google Scholar
  2. Bathien N, Hugon M (1964) Etude chez l'Homme de la depression d'un reflexe monosynaptique par stimulation d'un nerf cutané. J Physiol (Paris) 56:285–286Google Scholar
  3. Bergmans J, Delwaide PJ, Gadea-Ciria M (1978) Short-latency effects of low-threshold muscular afferent fibres on different motoneuronal pools of the lower limb in man. Exp Neurol 60:380–385Google Scholar
  4. Burke D, Gandevia SC, McKeon B (1984) Monosynaptic and oligosynaptic contributions to human ankle jerk and H-reflex. J Neurophysiol 52:435–448PubMedGoogle Scholar
  5. Burke RE (1981) Motor units: anatomy, physiology and functional organization. In: Brooks VB (ed) Handbook of physiology, Sect 1. The nervous system, Vol 2. Motor control. American Physiological Society, Bethesda MD, pp 345–423Google Scholar
  6. Burke RE, Rymer WZ, Walsh JV (1973) Functional specialization in the motor unit population of cat medial gastrocnemius muscle. In: Stein RB, Pearson KG, Smith RS, Redford JB (eds) Control of posture and locomotion. Plenum, New York, pp 29–44Google Scholar
  7. Burke RE, Rymer WZ, Walsh Jr JV (1976) Relative strength of synaptic input from short-latency pathways to motor units of defined type in cat medial gastrocnemius. J Neurophysiol 39:447–458Google Scholar
  8. Crone C, Hultborn H, Jespersen B (1985) Reciprocal Ia inhibition from the peroneal nerve to soleus motoneurones with special reference to the size of the test reflex. Exp Brain Res 59:418–422Google Scholar
  9. Crone C, Hultborn H, Jespersen B, Nielsen J (1987) Reciprocal Ia inhibition between ankle flexors and extensors in man. J Physiol (Lond) 389:163–185Google Scholar
  10. Eccles RM, Lundberg A (1959) Synaptic actions in motoneurones by afferents which may evoke the flexion reflex. Arch Ital Biol 97:199–221Google Scholar
  11. Eccles JC, Eccles RM, Lundberg A (1957) The convergence of monosynaptic excitatory afferents onto many different species of alpha motoneurones. J Physiol (Lond) 137:22–50Google Scholar
  12. Eccles JC, Schmidt RF, Willis WD (1962) Presynaptic inhibition of the spinal monosynaptic reflex pathway. J Physiol (Lond) 161:282–297Google Scholar
  13. Fleshman JW, Munson JB, Sypert GW, Friedman WA (1981) Rheobase, input resistance, and motor unit type in medial gastrocnemius motoneurones in the cat. J Neurophysiol 46:1326–1338Google Scholar
  14. Fournier E, Katz R, Pierrot-Deseilligny E (1984) A re-evaluation of the pattern of group I fibre projections in the human lower limb on using randomly alternated stimulation. Exp Brain Res 56:193–195Google Scholar
  15. Fournier E, Meunier S, Pierrot-Deseilligny E, Shindo M (1986) Evidence for interneuronally mediated Ia excitatory effects to human quadriceps motoneurones. J Physiol (Lond) 377:143–169Google Scholar
  16. Gassel MM, Diamantopoulos E (1964) The effect of procaine nerve block on neuromuscular reflex regulation in man: an appraisal of the role of the fusimotor system. Brain 87:729–742Google Scholar
  17. Gustafsson B, Pinter MJ (1985) On factors determining orderly recruitment of motor units: a role for intrinsic membrane properties. Trends Neurosci 8:431–433Google Scholar
  18. Hennemann E, Mendell LM (1981) Functional organization of motoneuron pool and its inputs. In: Brooks VB (ed) Handbook of physiology, Section 1. The nervous system, Vol 2. Motor control. American Physiological Society, Bethesda, pp 423–507Google Scholar
  19. Hoffmann R (1918) Über die Beziehungen der Sehnenreflexe zur willkürlichen Bewegung und zum Tonus. Z Biol 68:351–370Google Scholar
  20. Holmqvist B (1961) Crossed spinal reflex actions evoked by volleys in somatic afferents. Acta Physiol Scand 52: Suppl 181, pp 1–66Google Scholar
  21. Hultborn H, Katz R, Mackel R (1988a) Distribution of recurrent inhibition within a motor nucleus. II. Amount of recurrent inhibition in motoneurones to fast and slow units. Acta Physiol Scand 134:363–374Google Scholar
  22. Hultborn H, Lipski J, Mackel R, Wigström H (1988b) Distribution of recurrent inhibition within a motor nucleus. I. Contribution from slow and fast motor units to the excitation of Renshaw cells. Acta Physiol Scand 134:347–361Google Scholar
  23. Hultborn H, Meunier S, Morin C, Pierrot-Deseilligny E (1987) Assessing changes in presynaptic inhibition of Ia fibres: a study in man and the cat. J Physiol (Lond) 389:729–756Google Scholar
  24. Hunt CC (1955) Monosynaptic reflex response of spinal motoneurons to graded afferent stimulation. J Gen Physiol 38:813–852Google Scholar
  25. Jankowska E, Lundberg A, Rudomin P, Sykova E (1977) Effects of 4-aminopyridine on transmission in excitatory and inhibitory synapses in the spinal cord. Brain Res 136:387–392Google Scholar
  26. Kernell D, Hultborn H (1990) Synaptic effects on recruitment gain: a mechanism of importance for the input-output relations of motoneurone pools? Brain Res (in press)Google Scholar
  27. Kuno M (1959) Excitability following antidromic activation in spinal motoneurones supplying red muscles. J Physiol (Lond) 149:374–393Google Scholar
  28. Landau WM, Clare MH (1964) Fusimotor function. VI. H-reflex, tendon jerk, and reinforcement in hemiplegia. Arch Neurol 10:128–134Google Scholar
  29. Lloyd DPC (1941) A direct central inhibitory action of dromically conducted impulses. J Neurophysiol 4:184–190Google Scholar
  30. Lundberg A (1975) Control of spinal mechanisms from the brain. In: Tower DB (ed) The nervous system: the basic neurosciences, Vol 1. Raven, New York, pp 253–265Google Scholar
  31. Magladery JW, Porter WE, Park AM, Teasdall RD (1951) Electrophysiological studies of nerve and reflex activity in normal man. IV. The two-neurone reflex and identification of certain action potentials from spinal roots and cord. Johns Hopkins Hosp Bull 88:499–519Google Scholar
  32. Malmgren K, Pierrot-Deseilligny E (1988) Evidence for non-monosynaptic Ia excitation of human wrist flexor motoneurones, possibly via propriospinal neurones. J Physiol (Lond) 405:747–764Google Scholar
  33. Mazières L (1982) L'effet d'une stimulation conditionnante dépend de l'amplitude du reflexe monosynaptique test: étude chez l'homme et chez le chat. Thesis. Université Pierre et Marie Curie, ParisGoogle Scholar
  34. Mazières L, Morin C, Pierrot-Deseilligny E (1984) Effet de l'amplitude du reflexe test sur le niveau de facilitation ou d'inhibition des réponses monosynaptiques. J Physiologie 79:59AGoogle Scholar
  35. Meinck HM (1980) Facilitation and inhibition of the human H-reflex as a function of the amplitude of the control reflex. Electroenceph Clin Neurophysiol 48:203–211Google Scholar
  36. Morin C, Pierrot-Deseilligny E, Hultborn H (1984) Evidence for presynaptic inhibition of muscle spindle Ia afferents in man. Neurosci Lett 44:137–142Google Scholar
  37. Paillard J (1955) Réflexes et régulation d'origine proprioceptive chez l'homme. Arnette, ParisGoogle Scholar
  38. Pierrot-Deseilligny E, Morin C, Bergego C, Tankov N (1981) Pattern of group I fibre projections from ankle flexor and extensor muscles in man. Exp Brain Res 42:337–350Google Scholar
  39. Pollock LJ, Davis L (1930) The reflex activities of a decerebrate animal. J Comp Neurol 50:377–411Google Scholar
  40. Renshaw B (1940) Activity in the simplest spinal reflex pathways. J Neurophysiol 3:373–387Google Scholar
  41. Renshaw B (1941) Influence of discharge of motoneurons upon excitation of neighboring motoneurons. J Neurophysiol 4:167–183Google Scholar
  42. Schieppati M (1987) The Hoffmann reflex: a means of assessing spinal reflex excitability and its descending control in man. Prog Neurobiol 28:345–376CrossRefPubMedGoogle Scholar

Copyright information

© Springer-Verlag 1990

Authors and Affiliations

  • C. Crone
    • 1
  • H. Hultborn
    • 1
  • L. Mazières
    • 2
  • C. Morin
    • 2
  • J. Nielsen
    • 1
  • E. Pierrot-Deseilligny
    • 2
  1. 1.Department of NeurophysiologyPanum Institute, University of CopenhagenCopenhagen NDenmark
  2. 2.Clinical Neurophysiology, Department of RééducationHôpital de la SalpêtrièreParis Cedex 13France

Personalised recommendations