Electrical Stimulation of a Denervated Muscle Promotes Selective Reinnervation by Native Over Foreign Motoneurons

Abstract

The effect of electrical stimulation of the denervated posterior cricoarytenoid (PCA) muscle on its subsequent reinnervation was explored in the canine. Eight animals were implanted with a planar array of 36 electrodes for chronic stimulation and recording of spontaneous and evoked electromyographic (EMG) potentials across the entire fan-shaped surface of a muscle pair. Normative EMG data were recorded from each electrode site before unilateral nerve section, and from the innervated partner after nerve section. After randomizing the animals to experimental and control groups, the right recurrent laryngeal nerve innervating the PCA abductor muscle and its adductor antagonists was sectioned and reanastomosed. The PCA muscle in four experimental animals was continuously stimulated during the 11-mo experiment, using a 1-s, 30-pps, biphasic pulse train composed of 1-ms pulses 2-6 mA in amplitude and repeated every 10 s. The remaining four animals served as nonstimulated controls. Appropriate reinnervation by native inspiratory motoneurons was indexed behaviorally by the magnitude of vocal fold opening and electromyographically by the potential across all electrode sites. Inappropriate reinnervation by foreign adductor motoneurons was quantitated by recording EMG potentials evoked reflexly by stimulation of sensory afferents of the laryngeal mucosa. All four experimental animals showed a greater level of correct PCA muscle reinnervation (P < 0.0064) and a lesser level of incorrect reinnervation (P < 0.0084) than the controls. Direct muscle stimulation also appeared to enhance the overall magnitude of reinnervation, but the effect was not as strong (P < 0.113). These findings are consistent with a previous report and suggest that stimulation of a mammalian muscle may profoundly affect its receptivity to reinnervation by a particular motoneuron type.

Advances in peripheral nerve regeneration as it relates to VCA

“…Electrical stimulation is thought to decrease the rate of muscle atrophy and improve skeletal muscle receptiveness to reinnervation. 66,72 Fewer studies have looked at the effect of electrical stimulation of the proximal nerve stump, but the preliminary data on this topic provides exciting results. Al Majed et al have reported that, in a rat model, one hour of immediate direct electrical stimulation of the proximal nerve stump resulted in a significant increase in the kinetics of targeted muscle reinnervation.…”

Comparative studies on the implantation of nano platinum black and pure platinum electrodes in the rabbit orbicularis oculi muscle

“…In our experiments, filamentous cotton was used to touch the rabbit cornea with continuous stimulation for 10 seconds, and eye closure was measured with EMG (i.e. activity reflecting induced eye closure, as opposed to spontaneous eye closure occurring without external stimulation 8 ). The average amplitude related to induced eye closure for the two types of electrodes was recorded for 28 days for statistical comparison.…”

Modulation of trophism and fiber type gene expression in denervated muscle activated by different patterns of electrical stimulation. Role of muscle fiber regeneration revisited in 2017

“…These treatments usually start late after denervation because of clinical constraints and/or the outdated beliefs that electrical stimulation is useless in these cases and may actually interfere with eventual myofiber reinnervation. These beliefs are still held by some people despite recent evidence that electrostimulation may accelerate nerve growth and proper muscle reinnervation [10][11][12][13]. Effects of long-term denervation, of spontaneous or induced aneural myogenesis, and of long-term electrical stimulation (starting early or late after denervation) are discussed here.…”