Somatopetal transport of horseradish peroxidase following incorporation into axonal sprouts and axons in neuromas after nerve transection.

Horseradish peroxidase (HRP) applied to the proximal stump of the facial nerve of the mouse 5 h after section diffused into the endoneurium and was incorporated by endocytosis into axons densely packed with organelles. By 24 h to 16 days after the section, uptake of the tracer into profiles of outgrowing axonal sprouts rich in vesicles and vacuoles was registered. Subsequently HRP accumulated in corresponding perikarya. Tracer transport from neuromas was demonstrated 32 and 64 days after section. In this way influences from outgrowing nerve sprouts and axons in neuromas may reach nerve cell bodies.