Neural Supply to the Clitoris: Immunohistochemical Study with Three-Dimensional Reconstruction of Cavernous Nerve, Spongious Nerve, and Dorsal Clitoris Nerve in Human Fetus

Abstract

Introduction Little detailed information is available concerning autonomic and somatic nerve supply to the clitoris, potentially causing difficulties for nerve preservation during pelvic and perineal surgery. Aim To identify the location and type (nitrergic, adrenergic, cholinergic and sensory) of nerve fibers in the clitoris and to provide a three-dimensional (3D) representation of their structural relationship in the human female fetus. Methods Serial transverse sections were obtained from five human female fetuses (18–31 weeks of gestation) and subjected to histological and immunohistochemical investigations; digitized serial sections were used to construct a 3D representation of the pelvis. Main Outcome Measures Pelvic-perineal nerve location and type were evaluated qualitatively. Results The female neurovascular bundle (NVB) is the anteroinferior terminal portion of the inferior hypogastric plexus that runs along the postero-lateral then lateral face of the vagina and is rich in nNOS-positive fibers. The cavernous nerve (CN) is a thin ventrocaudal collateral projection of the NVB, and this projection does not strictly follow the NVB course. The CN runs along the lateral surface of the vagina and urethra and penetrates the homolateral clitoral crus. The CN provides adrenergic, cholinergic, and nitrergic innervation to the clitoris, but not sensory innervation. The spongious nerve (SN) is the terminal and main projection of the NVB and provides nitrergic innervation to the vestibular bulbs. The dorsal clitoris nerve (DCN), somatic branche of the pudendal nerve, runs along the superior surface of the clitoral crus and body and has a segmental proerectile nitrergic activity related to communicating branches with the CN. Conclusions “Computer-assisted anatomic dissection” allowed the identification of the precise location and distribution of the autonomic and somatic neural supply to female erectile bodies, providing an anatomical basis for nerve-sparing surgical techniques, and participating to the understanding of neurogenic female sexual dysfunction.

Levator ani muscle innervation: Anatomical study in human fetus

“…We used polyclonal antibodies against PS100, TH, VACHT, PMP22, and nNOS because of their validity. Indeed, we already demonstrated the internal validity with a high reproducibility . Moreover, external validity of these antibodies has been also demonstrated by others teams .…”

“…Therefore, although VACHT antibody is suitable for parasympathetic neurons, interpretation of labeling remains questionable as it is impossible to claim that all VACHT positive nerve fibbers are parasympathetic. Finally, nNOS is a marker of parasympathetic pro‐erectile fibers previously used to describe dorsal nerve of clitoris, and cavernous nerve pathways (positive control in our study) justifying its use in the current study …”

“…The nNOS is generated in human erectile bodies and is mostly found in the cavernous tissue of the clitoris and penis, particularly in the pro‐erectile nerve bundles and vascular and sinusoidal endothelium. nNOS antiserum labels a 155‐kDa peptide on Western blots of mouse brain (quality control data) …”

Female reproductive tract pain: targets, challenges, and outcomes

“…The external genitalia are essentially somatic structures and the distribution of sensory axons and their neurochemical coding are similar to cutaneous tissues (Martin-Alguacil et al, 2008; Moszkowicz et al, 2011; Vilimas et al, 2011). Sensory neurons innervating the hollow organs show different patterns of neurochemical expression compared with those that supply somatic structures (skin, muscle, and joints; Cervero and Laird, 2004; Song et al, 2009) and marked differences in central axons termination in the spinal cord (Sugiura et al, 1989, 1993).…”

“…These have a prevalence of around 10% in U.S studies (Harlow and Stewart, 2003; Petersen et al, 2008). Most sensations from the external genitalia are transmitted via axons in the pudendal nerve (Martin-Alguacil et al, 2008; Moszkowicz et al, 2011; Vilimas et al, 2011; Figure 1 ). Limited data indicate that often pain from these structures is similar to generalized somatic pain as opposed to visceral pain (Bachmann et al, 2006; Goldstein and Burrows, 2008).…”