THE EFFECT OF DURATION OF MUSCLE DENERVATION ON FUNCTIONAL RECOVERY IN THE RAT MODEL

The effect of long-term denervation on neuromuscular recovery was stud ied in a rat hind limb model. The posterior tibial nerve was transecte d and repaired immediately or after denervation periods of 2 weeks, or 1, 3, 6, 9, or 12 months. Six months following reconstruction excelle nt axonal regeneration was seen across all nerve repairs irrespective of periods of denervation. However, ?here was a precipitous and profou nd decrease in the recovery of both muscle mass and integrated motor f unction if the reconstruction was delayed for longer than 1 month. Rat her than a progressive change proportional to the length of the denerv ation period, significant, more discrete changes occurred sometime aft er 1 month of denervation that precluded a full recovery of muscle mas s. Integrated motor function quantified using walking track analysis w as impaired even after immediate nerve repair. (C) 1997 John Wiley & S ons, Inc.