title: Muscle fiber recovery functions studied with double pulse stimulation.
abstract: Direct electrical stimulation with paired pulses at varied intervals was used to study the propagation velocity and action potential amplitude recovery functions (VRF and ARF) of single muscle fibers. Following a subnormal period with slowed conduction, most of the muscle fibers tested in healthy subjects showed a period of supernormal propagation velocity starting at 3 to 12 ms, with a peak between about 5 and 15 ms, a mean increase of 7%, and an approximately logarithmic decay toward 1 second. The onset of supernormality was earlier in muscle fibers from patients with muscular dystrophy and significantly delayed in those from denervated muscles. Denervated muscle fibers also had a significantly longer refractory period.
authors.affiliation: University Institute of Clinical Neurophysiology, University Medical Center, Ljubljana, Yugoslavia.
authors.forename: M
authors.initials: M
authors.lastname: Mihelin
authors.forename: J V
authors.initials: JV
authors.lastname: Trontelj
authors.forename: E
authors.initials: E
authors.lastname: Stålberg
mesh_terms: D000200:Action Potentials / Q000502:physiology; D004576:Electromyography / Q000379:methods; D006801:Humans; D009119:Muscle Contraction / Q000502:physiology*; D009121:Muscle Denervation; D009132:Muscles / Q000502:physiology*; D009136:Muscular Dystrophies / Q000503:physiopathology; D009431:Neural Conduction / Q000502:physiology*; D012032:Refractory Period, Electrophysiological / Q000502:physiology; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors