Morphometry of nerves responsible for sensory innervation of the hind limbs in rats

Abstract

The sensory innervation of the distal hind limb is achieved by branches of the sacral and lumbar plexuses. In rats, the skin of the dorsum of the foot is innervated mainly by the sural and saphenous nerves, with considerable overlapping between them. We aimed to compare the morphology and morphometry of the sural and saphenous nerves in young rats. Female Wistar rats (N=5) aged 30 days were perfused with 2.5% glutaraldehyde and had their right and left sural and saphenous nerves prepared for light microscopy and morphometry. Comparisons were made between segments (proximal and distal) and sides in the same nerves and between nerves of the same side. Both nerves are longitudinally symmetric on both sides. A lateral symmetry is also present on both nerves. In general, no differences were found between nerves, either for the fascicle or for the myelinated fibers morphometry. The similar number of myelinated fibers, associated with their similar size in both sural and saphenous nerves suggests that the innervation territory for both nerves is equally distributed. This information is useful for studies of sensory neuropathies, in particular, studies of pain.Grant Funding Source : FAPESP, CNPq, CAPES and FAEPA