Evaluation of three techniques to demonstrate retrograde transport of horseradish peroxidase

Three methods of tracing neural connections by the use of horseradish peroxidase (HRP) were evaluated: (1) endoneurium injection, (2) injection followed by crushing at site of injection, and (3) nerve transection followed by capping of the proximal stump with a silicone cylinder containing HRP. The capping technique resulted in increased uptake and more uniform distribution of HRP in the nerves under study.