Skip to main content
SpringerLink
Log in

The “fastness” of rat motoneurones: time-course of afterhyperpolarization in relation to axonal conduction velocity and muscle unit contractile speed

  • Published:
Pflügers Archiv Aims and scope Submit manuscript

Abstract

In normal adult rats, intracellular recordings were obtained from motoneurones of the medial gastrocnemius (MG) and other tibial-nerve muscle branches. Among the whole population of tibial motoneurones, there was a significant negative correlation between the duration of afterhyperpolarization (AHP) and axonal conduction velocity (CV). However, this AHP vs CV relationship differed from that previously demonstrated in cats, in that for a given axonal CV, the AHPs were briefer in the rat than in the cat. For MG cells, twitches were also recorded from their muscle units. As has previously been observed in cats, there was a significant correlation between the time-course of the AHP of a motoneurone and the time-course of its muscle unit twitch. This relationship was, in principle, similar between the two species, but the AHPs and the twitches were briefer in the rat. The present results provide the first demonstration, for the rat model, of the presence of a functionally relevant “speed-match” between the intrinsic properties of α-motoneurones and those of their muscle units.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Bradley K, Somjen GG (1961) Accomodation in motoneurones of the rat and the cat. J Physiol (Lond) 156:75–92

    CAS  Google Scholar 

  • Burke RE (1967) Motor unit types of cat triceps surae muscle. J Physiol (Lond) 193:141–160

    Google Scholar 

  • Burke RE, Strick PL, Kanda K, Kim CC, Walmsley B (1977) Anatomy of medial gastrocnemius and soleus motor nuclei in cat spinal cord. J Neurophysiol 40:667–680

    PubMed  CAS  Google Scholar 

  • Close R (1967) Dynamic properties of fast and slow skeletal muscles of mammals. In: Milhorat AT (ed) Exploratory concepts in muscular dystrophy and related disorders. (International congress series no. 147) Excerpta Medica, Amsterdam, pp 142–149

    Google Scholar 

  • Cooper S, Eccles JC (1930) The isometric responses of mammalian muscles. J Physiol (Lond) 69:377–385

    CAS  Google Scholar 

  • Crill WE, Schwindt PC (1984) Ionic mechanisms underlying the excitation-to-frequency transduction: studies by voltage clamp methods. Arch Ital Biol 122:31–41

    PubMed  CAS  Google Scholar 

  • Cullheim S (1978) Relations between cell body size, axon diameter and axon conduction velocity of cat sciatic α-motoneurons stained with horseradish peroxidase. Neurosci Lett 8:17–20

    Article  Google Scholar 

  • Dum RP, Kennedy TT (1980) Physiological and histochemical characteristics of motor units in cat tibialis anterior and extensor digitorum longus muscles. J Neurophysiol 43:1615–1630

    PubMed  CAS  Google Scholar 

  • Eccles JC, Eccles RM, Lundberg A (1958) The action potentials of the alpha motoneurones supplying fast and slow muscles. J Physiol (Lond) 142:275–291

    CAS  Google Scholar 

  • Foehring RC, Sypert GW, Munson JB (1986) Properties of selfreinnervated motor units of medial gastrocnemius of the cat. 1. Long-term reinnervation. J Neurophysiol 55:931–946

    PubMed  CAS  Google Scholar 

  • Gardiner PF, Olha AE (1987) Contractile and electromyographic characteristics of rat plantaris motor unit types during fatiguein situ. J Physiol (Lond) 385:13–34

    CAS  Google Scholar 

  • Gustafsson B (1984) Afterpotentials and transduction properties in different types of central neurones. Arch Ital Biol 122:17–30

    PubMed  CAS  Google Scholar 

  • Gustafsson B, Pinter MJ (1984) Relations among passive electrical properties of lumbar α-motoneurones of the cat. J Physiol (Lond) 356:401–431

    CAS  Google Scholar 

  • Hammarberg C, Kellerth J-O (1975) Studies of some twitch and fatigue properties of different motor unit types in the ankle muscles of the adult cat. Acta Physiol Scand 95:231–242

    PubMed  CAS  Google Scholar 

  • Hashizume K, Kanda K, Burke RE (1988) Medial gastrocnemius motor nucleus in the rat: age-related changes in the number and size of motoneurons. J Comp Neurol 269:425–430

    Article  PubMed  CAS  Google Scholar 

  • Huizar P, Kuno M, Kudo N, Miyata Y (1977) Reaction of intact spinal motoneurones to partial denervation of the muscle. J Physiol (Lond) 265:175–191

    CAS  Google Scholar 

  • Kanda K, Hashizume K (1989) Changes in properties of the medial gastrocnemius motor units in aging rats. J Neurophysiol 61:737–746

    PubMed  CAS  Google Scholar 

  • Kernell D (1965) The limits of firing frequency in cat lumbosacral motoneurones possessing different time course of afterhyperpolarization. Acta Physiol Scand 65:87–100

    Article  Google Scholar 

  • Kernell D (1979) Rhythmic properties of motoneurones innervating muscle fibres of different speed in m. gastrocnemius medialis of the cat. Brain Res 160:159–162

    Article  PubMed  CAS  Google Scholar 

  • Kernell D (1983) Functional properties of spinal motoneurons and gradation of muscle force. In: Desmedt JE (ed) Motor control mechansms in health and disease. (Advances in neurology, vol 39) Raven Press, New York, pp 213–226

    Google Scholar 

  • Kernell D (1984) The meaning of discharge rate: excitation-to-frequency transduction as studied in spinal motoneurones. Arch Ital Biol 122:5–15

    PubMed  CAS  Google Scholar 

  • Kernell D (1990) Spinal motoneurons and their muscle fibers: mechanisms and long-term consequences of common activation patterns. In: Binder MD, Mendell LM (eds) The segmental motor system. Oxford University Press, New York, pp 36–57

    Google Scholar 

  • Kernell D, Zwaagstra B (1981) Input conductance, axonal conduction velocity and cell size among hindlimb motoneurones of the cat. Brain Res 204:311–326

    Article  PubMed  CAS  Google Scholar 

  • Kernell D, Eerbeek O, Verhey BA (1983) Relation between isometric force and stimulus rate in cat's hindlimb motor units of different twitch contraction time. Exp Brain Res 50:220–227

    PubMed  CAS  Google Scholar 

  • Kugelberg E, Lindegren B (1979) Transmission and contraction fatigue of rat motor units in relation to succinate dehydrogenase activity of motor unit fibres. J Physiol (Lond) 288:285–300

    CAS  Google Scholar 

  • Kuno M (1959) Excitability following antidromic activation in spinal motoneurones supplying red muscles. J Physiol (Lond) 149:374–393

    CAS  Google Scholar 

  • Kuno M, Miyata Y, Muñoz-Martinez EJ (1974) Differential reaction of fast and slow α-motoneurones to axotomy. J Physiol (Lond) 240:725–739

    CAS  Google Scholar 

  • Luff AR (1975) Dynamic properties of fast and slow skeletal muscles in the cat and rat following cross-reinnervation. J Physiol (Lond) 248:83–96

    CAS  Google Scholar 

  • Schnepp G, Schnepp P, Spaan G (1971) Faseranalytische Untersuchungen an peripheren Nerven bei Tieren verschiedener Größe. I. Fasergesamtzahl, Faserkaliber und Nervenleitungsgeschwindigkeit. Z Zellforsch 119:77–98

    Article  PubMed  CAS  Google Scholar 

  • Swett JE, Wikholm RP, Blanks RHI, Swett AL, Conley LC (1986) Motoneurons of the rat sciatic nerve. Exp Neurol 93:227–252

    Article  PubMed  CAS  Google Scholar 

  • Zengel JE, Reid SA, Sypert GW, Munson JB (1985) Membrane electrical properties and prediction of motor-unit type of medial gastrocnemius motoneurons in the cat. J Neurophysiol 53: 1323–1344

    PubMed  CAS  Google Scholar 

  • Zwaagstra B, Kernell D (1980) The duration of after-hyperpolarization in hindlimb alpha motoneurones of different sizes in the cat. Neurosci Lett 19:303–307

    Article  PubMed  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Neurophysiology, University of Amsterdam, Academisch Medisch Centrum, Meibergdreef 15, NL-1105, AZ Amsterdam, The Netherlands

    P. F. Gardiner & D. Kernell

Authors
  1. P. F. Gardiner
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. D. Kernell
    View author publications

    You can also search for this author in PubMed Google Scholar

Additional information

Worked on the experiments while on leave of absence during subbatical year from Département d'éducation physique, Université de Montréal, Montréal, Québec, Canada H3C 3J7

Rights and permissions

Reprints and permissions

About this article

Cite this article

Gardiner, P.F., Kernell, D. The “fastness” of rat motoneurones: time-course of afterhyperpolarization in relation to axonal conduction velocity and muscle unit contractile speed. Pflugers Arch. 415, 762–766 (1990). https://doi.org/10.1007/BF02584018

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF02584018

Keywords

Search

Navigation