Mechanisms promoting selective regeneration of motor axons following peripheral nerve injury

It is well established that peripheral nerves regenerate following injury. Consequently, incomplete recovery of motor function usually happens, not because regeneration does not occur, but because regenerating peripheral axons often reinnervate the wrong targets. Treatment strategies that improve regeneration accuracy will undoubtedly lead to better clinical outcomes for patients with peripheral nerve injuries. However, despite this appreciation, surprisingly very little is known about the mechanisms that regulate motor axon guidance during regeneration. The focus of this proposal is to better understand the molecular mechanisms involved in axon targeting of regenerating motoneurons. Using genetically engineered mice we will determine whether one particular molecule, known as polysialylated neural cell adhesion molecule (PSA-NCAM) regulates motor axon targeting after peripheral nerve injury. The goal of this project is to provide valuable scientific information that will ultimately lead to better strategies for treating peripheral nerve injuries. Furthermore, we expect that much of this knowledge will be applicable to regenerating spinal neurons damaged after a spinal cord injury.