Journal of Muscle Research and Cell Motility

, Volume 28, Issue 4, pp 203–217

Effects of chronic electrical stimulation on long-term denervated muscles of the rabbit hind limb

Authors

  • Zoe Ashley
    • Muscle Research Group, Department of Human Anatomy & Cell Biology, School of Biomedical SciencesUniversity of Liverpool
    • Muscle Research Group, Department of Human Anatomy & Cell Biology, School of Biomedical SciencesUniversity of Liverpool
  • Simona Boncompagni
    • IIM Interuniversity Institute of Myology, Centro Scienze dell’Invecchiamento (Center for Research on Ageing)Università G. d’Annunzio
  • Feliciano Protasi
    • IIM Interuniversity Institute of Myology, Centro Scienze dell’Invecchiamento (Center for Research on Ageing)Università G. d’Annunzio
  • Michael Russold
    • Muscle Research Group, Department of Human Anatomy & Cell Biology, School of Biomedical SciencesUniversity of Liverpool
    • Rehabilitation Research CentreUniversity of Sydney
  • Hermann Lanmuller
    • Department of Biomedical Engineering & PhysicsUniversity of Vienna, AKH
  • Winfried Mayr
    • Department of Biomedical Engineering & PhysicsUniversity of Vienna, AKH
  • Hazel Sutherland
    • Muscle Research Group, Department of Human Anatomy & Cell Biology, School of Biomedical SciencesUniversity of Liverpool
  • Jonathan C. Jarvis
    • Muscle Research Group, Department of Human Anatomy & Cell Biology, School of Biomedical SciencesUniversity of Liverpool
Original Paper

DOI: 10.1007/s10974-007-9119-4

Cite this article as:
Ashley, Z., Salmons, S., Boncompagni, S. et al. J Muscle Res Cell Motil (2007) 28: 203. doi:10.1007/s10974-007-9119-4

Abstract

We investigated the extent to which activity induced by chronic electrical stimulation could restore the mass and contractile function of rabbit tibialis anterior (TA) muscles that had undergone atrophy as a result of prolonged denervation. Denervation was carried out by selectively interrupting the motor nerve branches to the ankle dorsiflexors in one hind limb. Stimulators were implanted, with electrodes on the superficial and deep surfaces of the denervated TA muscle. Ten weeks later, the mass and mid-belly cross-sectional area (CSA) of TA muscles subjected to denervation alone had fallen to approximately 40% of normal. At this stage, stimulators in the other rabbits were activated for 1 h/day to deliver 20-ms rectangular bipolar constant-current pulses of 4 mA amplitude at 20 Hz with a duty cycle of 1s ON/2s OFF, a total of 24,000 impulses/day. The animals were examined after a further 2, 6 or 10 weeks. Stimulation restored the wet weight of the denervated muscles to values not significantly different to those of normal, innervated controls. It increased CSA from 39% to 66% of normal, and there was a commensurate increase in maximum isometric tetanic force from 27% to 50% of normal. Light and electron microscopic examination revealed a marked improvement in the size, packing, and internal organization of the stimulated-denervated muscle fibres, suggestive of an ongoing process of restoration. Excitability, contractile speed, power, and fatigue resistance had not, however, been restored to normal levels after 10 weeks of stimulation. Similar results were found for muscles that had been denervated for 39 weeks and then stimulated for 12 weeks. The study demonstrates worthwhile benefits of long-term electrical stimulation in the treatment of established denervation atrophy.

Keywords

Denervated muscleElectrical stimulationRabbitTibialis anterior muscleImplantable deviceLong-termAtrophyPhysiologyLight microscopyElectron microscopy

Copyright information

© Springer Science+Business Media B.V. 2007