Crossed over repair of the femoral sensory and motor branches influences N-CAM.

N-CAM, expressed by non-myelinating Schwann cells, was investigated by immunohistochemistry in transected rat femoral nerves, which were repaired either using a straight or a crossed over technique. N-CAM staining covered 30 and 11% of the cross-sectional area of sensory and motor branches, respectively, in uninjured nerves. After 3 days there was a transient smaller area of N-CAM staining following both the repairs. After a straight repair N-CAM area increased to the control values in both branches. In contrast, a crossed over repair resulted in a continuous increase of N-CAM in the motor branch, whereas the area in the sensory branch returned slowly to control values. N-CAM is influenced by an intentionally misdirected outgrowth of motor and sensory axons after nerve repair.