Terminal innervation of the male genitalia, cutaneous sensory receptors of the male foreskin.

PURPOSE

Understanding the types of sensory nerve termini within the glabrous skin of the human male foreskin could throw light on surgical outcomes and therapeutic possibilities for the future. Various receptor types sense changes in temperature, position, pressure, pain, light touch, itch, burning and pleasurable sexual sensations. Similarities and differences in innervation characteristics and density might become apparent when the glans penis is compared with homologous structures in the female genitalia. The aim of this study is to document the presence and characteristics of cutaneous sensory receptors in the human penile foreskin using a histopathological study of the nerve termini to achieve a more complete understanding of sensory experiences.

METHODS

Foreskin samples were obtained from ten boys (aged 1-9 years) who had undergone circumcision. Informed consent was obtained from the parent/legal guardian. The samples were examined after modified Bielschowsky silver impregnation of neural tissue, and immunocytochemistry against gene protein product (PGP) 9.5 and neuron-specific enolase (NSE).

RESULTS

PGP 9.5 appeared to be the most sensitive neural marker. Free nerve endings were identified in the papillary dermis visualized as thin fibers, mostly varicose, with either branched or single processes, either straight or bent. Two types of sensory corpuscle were identified: capsulated and non-capsulated. Meissner-like corpuscles were located in the papillary dermis. Capsulated corpuscles resembled typical Pacinian corpuscles, comprising a single central axon surrounded by non-neural periaxonic cells and lamellae. The capsulated corpuscles were strongly positive for PGP 9.5 and NSE.

CONCLUSIONS

Free nerve endings, Meissner's corpuscles and Pacinian corpuscles are present in the human male foreskin and exhibit characteristic staining patterns.