CLR/RAMP1 and CGRP double-staining in rat C1. (A) RAMP1 and (B) CLR expression in rat C1. The receptor components are found from Lissauer's tract and within laminae I and II (arrows). Higher magnification discloses expression in the walls of the capillaries. (C) Co-expression of CLR (red) and RAMP1 (green) in the laminae and the capillaries. (D) Double-staining of CGRP (red, thick arrows) and RAMP1 (green, thin arrows) using confocal microscopy. CGRP and RAMP1 are not co-expressed. (E) Fluorescence and DAB staining of the receptor components. Positive fibers are displayed close to the central canal (arrows), where also positive capillaries are found (arrow heads).