Manual stimulation of forearm muscles does not improve recovery of motor function after injury to a mixed peripheral nerve

• Published in: Experimental brain research Vol. 185; no. 3; pp. 469 - 483
• Main Authors: Sinis, N., Guntinas-Lichius, O., Irintchev, A., Skouras, E., Kuerten, S., Pavlov, S. P., Schaller, H. E., Dunlop, S. A., Angelov, D. N.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01-03-2008; Springer; Springer Nature B.V
• Subjects: Animals; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Cranial nerves. Spinal roots. Peripheral nerves. Autonomic nervous system. Gustation. Olfaction; Female; Forelimb - innervation; Forelimb - physiology; Fundamental and applied biological sciences. Psychology; Medical sciences; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; Motor Neurons - physiology; Motor Skills - physiology; Muscle, Skeletal - innervation; Muscle, Skeletal - physiology; Nervous system (semeiology, syndromes); Neurology; Neurons, Afferent - physiology; Neurosciences; Peripheral Nerve Injuries; Peripheral Nerves - physiology; Physical Stimulation - methods; Rats; Rats, Inbred Lew; Recovery of Function - physiology; Research Article; Vertebrates: nervous system and sense organs; Axotomy; Axonal sprouting; Median nerve; Motoneuron; Polyinnervation; Forearm muscles; Motor endplates; Axonal sprouting, Forearm muscles; Peripheral nerve; Gripping; Rat; Force; Rodentia; Anastomosis; Facial nerve; Motor neuron; Axotomy, Median nerve; Vertebrata; Mammalia; Functional recovery; Sensory nerve; Upper limb; Muscle; Motor nerve
• ISSN: 0014-4819; 1432-1106
• DOI: 10.1007/s00221-007-1174-y

Transection and re-anastomosis of the purely motor facial nerve leads to poor functional recovery. However, we have recently shown in rat that manual stimulation (MS) of denervated vibrissal muscles reduces the number of polyinnervated motor endplates and promotes full recovery of whisking. Here, we examined whether MS of denervated rat forearm muscles would also improve recovery following transection and suture of the mixed (sensory and motor) median nerve (median–median anastomosis, MMA). Following MMA of the right median nerve, animals received no postoperative treatment, daily MS of the forearm muscles or handling only. An almost identical level of functional recovery, measured by the force of grip in grams, was reached in all animals by the sixth postoperative week and maintained till 3 months following surgery regardless of the postoperative treatment. Also, we found no differences among the groups in the degree of axonal sprouting, the extent of motor endplate polyinnervation and in the soma size of regenerated motoneurons. Taken together, we show that while MS is beneficial following motor nerve injury, combined strategies will be required for functional recovery following mixed nerve injury.