Nerve growth factor (NGF)-treated nitrocellulose enhances and directs the regeneration of adult rat dorsal root axons through intraspinal neural tissue transplants.

Severed adult rat dorsal roots were apposed to an intraspinal transplant of fetal spinal cord (FSC) tissue co-grafted with nerve growth factor (NGF)-treated nitrocellulose strips. Axonal regrowth from the injured roots was assessed by calcitonin gene-related peptide immunoreactivity (CGRP-IR). Dense fascicles of regenerating CGRP-IR axons lined the entire length of NGF-treated nitrocellulose, with many crossing the graft-host interface ventrally to extend into the host neuropil. In contrast, CGRP-IR axon regrowth was not promoted by untreated nitrocellulose implants. These results indicate that substrate bound NGF can promote and direct the intraspinal regeneration of a specific population of dorsal root axons.