Skip to main content
. Author manuscript; available in PMC: 2009 Feb 1.
Published in final edited form as: Exp Neurol. 2007 Jul 21;209(2):333–342. doi: 10.1016/j.expneurol.2007.06.026

Figure 2.

Figure 2

Overlapping gradients of NGF and semaphorin 3A restrict the regeneration of CGRP+ nociceptive axons to laminae I and II. A) Injection of NGF adenovirus into the dorsal horn of the spinal cord induces expression of a neurotrophin gradient (blue). B) This gradient supports the regeneration of peptidergic (CGRP+) nociceptive axons (red) throughout the entire dorsal horn, generating an abnormal innervation pattern. C) Co-expression of NGF (dorsally) and semaphorin 3A (ventrally, green) establishes slightly overlapping gradients that supports axon regeneration into the dorsal horn. D) As axons regenerate into the dorsal horn they encounter increasing amounts of semaphorin 3A that prevents their growth into deeper dorsal laminae to produce a reinnervation pattern similar to normal.