Figure 7.

Topography of cFos expression follows the pattern of CGRP axon regeneration. cFos immune reactivity (IR) was examined within two general regions, laminae I and II (superficial dorsal horn) or laminae III – VI (deep dorsal horn). A, In normal non-lesioned animals, Fos-IR-positive neurons are predominantly localized to the superficial dorsal horn (laminas I and II), with very few labeled cells in the deeper laminae. B, Following dorsal root crush injury a dramatic loss of Fos-IR cells is found on the ipsilateral side indicating no spontaneous regeneration in Lenti-GFP treated animals. C, NGF treatment resulted in high numbers of cFos positive cells localized throughout the ipsilateral superficial as well as deep dorsal horn. D, Artemin treated animals show cFos positive cells localized to ipsilateral superficial dorsal horn with very few cFos expressing cells in the deep dorsal horn. E, GDNF treated animals show very low cFos IR and the cFos IR neurons were randomly distributed in the spinal cord. F, Graph showing the distribution of cFos positive cells in the superficial and deep dorsal horn regions as shown in panel A. As seen in the images, the majority of cFos positive cells were present in the superficial laminae in normal and artemin treated animals, while NGF expressed animals showed cFos-IR cells in superficial as well as deep dorsal horn laminae in almost equal proportion. Values represent mean ±SEM, n=5 for no lesion control, n=6 for NGF, n=8 for artemin and GFP control, n=7 for GDNF *, δ p<0.05, Tukey’s post hoc test). Scale bar = 300 μm.