Strain differences in autotomy in rats undergoing sciatic nerve transection or repair.

The degree of self-mutilation (autotomy) following sciatic nerve injury was assessed in 6 rat strains. Experimental groups included sciatic nerve transection with and without repair and crush lesions. The degree of autotomy was measured using a standard grading system. There were statistically significant differences between the strains in the transected group in terms of both degree of autotomy and the time of onset of its appearance. The repair group showed a shorter mean time of onset, lower maximal scores, and lower percentage of affected animals. Autotomy was absent in the nerve crush group and in all Lewis rats. In experimental studies when the status of the foot is critical (e.g., to evaluate functional walking patterns) Lewis rats appear to be the most appropriate strain to utilize. These results suggest that there are definite strain differences in the degree of autotomy following nerve transection or repair.