Differential distribution of BDNF and TRKB in regenerating dorsal column axons

DORSAL column axons can regenerate into peripheral nerve grafts. The neurotrophin BDNF and its receptor TrkB are synthesized in dorsal root ganglion neurons, and have been implicated in regeneration. The aim of this study was to examine the distribution of BDNF and TrkB in dorsal column axons which regenerated into a peripheral nerve graft. BDNF-stained axons were found in all regions of the graft. BDNF was also expressed in small neurons in the superficial dorsal horn adjacent to the graft. TrkB was not found in any regenerating axons. Thus BDNF and TrkB are differentially expressed in regenerating dorsal column axons. In these axons BDNF may play a role that is independent of TrkB.