INACCURATE PROJECTION OF RAT SOLEUS MOTONEURONS - A COMPARISON OF NERVE REPAIR TECHNIQUES

The objectives of this study were 1) to determine the degree to which soleus motoneurons find their appropriate target following crush and t ransection injuries to the sciatic nerve, and 2) to determine whether repair of a transected nerve with a silicone tube leads to greater spe cificity of reinnervation and recovery of muscle function than the sta ndard epineurial suture repair method. Sixty adult female Sprague-Dawl ey rats were randomly assigned to one of three sciatic nerve injury gr oups: crush injury, transection with epineurial suture repair, or tran section with a silicone tube repair. The degree to which soleus motone urons were able to find their appropriate target following a sciatic n erve injury was examined using a double labeling dye technique in whic h the original soleus motor pool was labeled with fast blue and reinne rvating motoneurons were labeled with Dil. Soleus motoneurons were abl e to find their appropriate target following a crush injury. The accur acy of reinnervation following a transection injury and repair, howeve r, was relatively poor. Only 14% of the original soleus motoneurons fo und the correct target following a transection injury. Repair of a les ioned nerve with a silicone tube and a 5-mm gap as opposed to epineuri al sutures did not increase the specificity of reinnervation or the de gree of muscle recovery. (C) 1997 John Wiley & Sons, Inc.