Tract tracing of nerves of upper extremity using adenoviral vectors containing LacZ gene

Objective: To trace ulnar never, median nerves and their targeted neurons by remote delivery of adenoviral vectors containing LacZ gene (AdLacZ). Method: AdLacZ were administrated to the proximal stumps of ulnar nerves or median nerves in Wistar rats and the transected nerves were repaired. At different time points post transfection, the spinal cord of C4-T2 and their corresponding DRGs and brachial plexus nerves were harvested and processed for X-gal staining. Result: The motor neurons of ventral horns of spinal cords and sensory neurons of DRGs were labeled by transgene product β-gal in C7-T1 segments transfected from ulnar nerve and C6—T1 segments transfected from median nerves. The corresponding neural roots and nerve trunks of transfected nerves were also labeled. The number of labeled neurons of ulnar nerves was different from that of median nerves. The labeled neurons and axons could not be observed after several weeks post transfection. Conclusion: LacZ gene mediated by Ad could specially target the motor and sensory neurons retrogradely and then label the axons of the ulnar and median nerves anterogradely. This gene delivery method renders this system particularly attractive for neuroanatomical tracing studies of brachial plexus nerves and might offer potentialities for gene therapy of peripheral nerve injury.