[Vagal sensory reinnervation and composition of the sterno-cephalic muscle in rabbits].
The crossed nerve anastomosis between the peripheral end of the vagus nerve, cut above the nodose ganglion, and the peripheral end of the accessory nerve has demonstrated the capacity of some vagal afferents to reinnervate, via the accessory nerve stump, certain sternocephalicus muscle fibers in the rabbit. These results add to our understanding of the capacity of these afferents to counter the past-denervational atrophying process that occurs in the reinnervated muscles and to evaluate the changes induced in these muscles during reinnervation. Our work shows that within 3 months, the vagal sensory reinnervation of previously denervated sternocephalicus muscles induces their total weight recovery. This recovery is concomitant on the one hand with the hypertrophy of the four muscle fiber types (I, IIBD, IIC and IIA) identified histochemically in the normal muscles and, on the other, with the appearance of small newly formed myofibers, which are often underlined by characteristic central nuclei. The vagal sensory neurones induce important changes in the percentages and the muscle cross-sectional distribution of the fibers in reinnervated muscles. In these muscles we see also the disappearance of the fast myosin heavy chains MHCIIB and MHCIID, the upholding of the fast MHCIIA percentage and an increase in the slow MHCI isoform.
Ahidouch
A
A
Laboratoire de neurobiologie fonctionnelle, SN4, université des sciences et technologies de Lille, Villeneuve-d'Ascq, France.
Delorme
P
P
D000818:Animals; D005260:Female; D006651:Histocytochemistry; D018485:Muscle Fibers, Skeletal / Q000166:cytology; D018482:Muscle, Skeletal / Q000737:chemistry / Q000294:innervation*; D009218:Myosins / Q000032:analysis / Q000737:chemistry; D009416:Nerve Regeneration; D011817:Rabbits; D013537:Sutures; D014630:Vagus Nerve / Q000601:surgery*
D009218:Myosins