Reduction of autotomy following peripheral neurectomy by a single injection of bupivacaine into the cingulum bundle of rats.

Peripheral neurectomy in rats is followed by autotomy of the denervated zone, which is assumed to represent an index of pain or dysesthesia. In the present study, we examined whether a single injection of a local anesthetic (bupivacaine) into the cingulum bundle at the time of nerve section could reduce autotomy. It was found that a temporary anesthetic blockade of the cingulum at the time of nerve section delayed the onset and reduced the overall degree of autotomy. However, injections given shortly after nerve section had no significant effects. These results demonstrate that temporary blockade of cingulum activity at the time of nerve section reduces autotomy for periods that exceed the duration of the anesthetic block.