Origin and course of nerves immunoreactive for calcitonin gene-related peptide surrounding the femoral artery in rat

Appreciation of anatomic relationships between perivascular nerve fibers and blood vessels is essential in reconstructive surgery. We examined the origin and neural connections of perivascular nerve fibers containing calcitonin gene-related peptide surrounding the femoral artery that regulate vascular tone. We used immunohistochemistry, denervation, and retrograde labeling methods. Peptide-immunoreactive fibers surrounding the femoral artery formed a complex network, with numerous small fibers extending from nerve fiber bundles located in the perivascular connective tissue. In middle and distal arterial segments, these fibers originated from the femoral nerve, the arterys main accompanying nerve. More proximally, fibers arose from the genitofemoral nerve and sympathetic nerves. Nerve branches terminating in various arterial segments had origins corresponding to those of somatic sensory nerve fibers, although pathways innervating the femoral artery took different courses.