Reinnervation of muscles after transection of the sciatic nerve in adult rats

• Published in: Muscle & nerve Vol. 25; no. 6; pp. 891 - 897
• Main Authors: Ijkema-Paassen, Jos, Meek, Marcel F., Gramsbergen, Albert
• Format: Journal Article
• Language: English
• Published: New York Wiley Subscription Services, Inc., A Wiley Company 01.06.2002; Wiley
• Subjects: Animals; Axotomy; Biological and medical sciences; Disease Models, Animal; Fundamental and applied biological sciences. Psychology; Male; motor endplate; Motor Endplate - pathology; Motor Endplate - ultrastructure; Muscle, Skeletal - innervation; Muscle, Skeletal - pathology; Muscle, Skeletal - physiology; Nerve Regeneration - physiology; Peripheral nervous system. Autonomic nervous system. Neuromuscular transmission. Ganglionic transmission. Electric organ; polyneuronal innervation; rat; Rats; Rats, Wistar; Recovery of Function - physiology; reinnervation; Sciatic Nerve - physiology; Sciatic Nerve - physiopathology; sciatic nerve transection; Sciatic Neuropathy - pathology; Sciatic Neuropathy - physiopathology; Time; Vertebrates: nervous system and sense organs; Rat; Innervation; Rodentia; Striated muscle; Soleus muscle; Anterior tibial muscle; Neuromuscular junction; Locomotion; Vertebrata; Mammalia; Functional recovery; Morphology; Motor nerve; Reinnervation; Gastrocnemius muscle; Age; Sciatic nerve; Denervation
• ISSN: 0148-639X; 1097-4598
• DOI: 10.1002/mus.10130

Functional recovery after transection of the sciatic nerve in adult rats is poor, probably because of abnormalities in reinnervation. Denervation and reinnervation patterns were studied morphologically in the lateral gastrocnemius (LGC), tibialis anterior (TA), and soleus (SOL) muscles for 21 weeks after nerve transection (motor endplates by acetylcholinesterase staining; nerves by silver impregnation). Motor endplates in the TA showed improving morphology with age, and, at 21 weeks, three‐quarters of these were normal. Poorest recovery was observed in the SOL, as, at 21 weeks, only one‐third of the motor endplates had a normal morphology. Polyneuronal innervation initially was more pronounced in the SOL, but, at 21 weeks, 10% of the motor endplates in all three muscles were still polyneuronally innervated. Our results indicate important differences in the reinnervation of these three hindleg muscles, and, even at 5 months, abnormalities were still present. These factors may in part explain the abnormal locomotion in rats as well as the limited recovery of function observed clinically in humans after nerve transection. © 2002 Wiley Periodicals Inc. Muscle Nerve 25: 000–000, 2002