EVIDENCE OF SYMPATHETIC FIBERS IN THE MALE-RAT PELVIC NERVE BY GROSS-ANATOMY, RETROGRADE LABELING AND HIGH-RESOLUTION AUTORADIOGRAPHIC STUDY

Several arguments exist in various animal species and man for the pres ence of a sympathetic component in the pelvic nerve, classically regar ded as parasympathetic. We tested this hypothesis in the male rat. Ner ve bundles issued from the sacral region of the paravertebral sympathe tic chain and reaching the S1 spinal nerve were identified. Neurons in the sacral parasympathetic nucleus of the L6-S1 spinal cord and in th e L2-S1 paravertebral sympathetic chain were retrogradely labeled from the pelvic nerve. Radioautography evidenced labeling of unmyelinated fibers in the pelvic nerve following in vitro incubation with H-3-nora drenaline. A population of sympathetic fibers issued from the lumbosac ral sympathetic chain exists in the pelvic nerve of the male rat. This qualitative study provides a morphological basis to uncover the role of the sympathetic outflow present in the pelvic nerve.