Figure 2

Confocal images of the rat's hindpaw skin in saline-treated (A and B) and CFA-treated (C and D) rats, at 30 days post-injection. The material was processed for double immunofluorescence as described in the methods section, and examined with a Zeiss LSM 510 confocal microscope. CGRP immunoreactivity is shown in green and DBH immunoreactivity in red. Except for D that represents a single optical section, images represent z-stacks projected in the horizontal plane to show an extended focus. In A, note that in saline treated rats, the sympathetic fibers (DBH-IR), in red, are not observed in the upper dermis. In B, note that in the lower dermis of saline-treated rats sympathetic fibers can be observed in association with an arteriole, which is also innervated by CGRP-IR fibers. In contrast, in B and C, which were taken from CFA-treated rats, note the presence of sympathetic fibers in the upper dermis; although in both images they were observed travelling along the dermal-epidermal junction, most such fibers did not get as close to the epidermis. In C, note that the sympathetic fibers in the upper dermis often wrap around CGRP-IR fibers; arrows show zones of close apposition of the two fiber types (A), although they are detected in the lower dermis around blood vessels (B).