Correlation between the distribution of SP and CGRP immunopositive neurons in dorsal root ganglia and the afferent sensation of preputial frenulum

Anat Rec (Hoboken). 2011 Mar;294(3):479-86. doi: 10.1002/ar.21327. Epub 2010 Dec 31.


The aim of this study was to explore the distribution of substance P (SP) and calcitonin gene-related peptide (CGRP) immunoreactive nerve terminals in the penis prepuce and the preputial frenulum. The possible correlation between SP- and CGRP-immunopositive neurons in dorsal root ganglia (DRG) and the afferent sensation of the penile preputial frenulum is also discussed. Immunohistochemistry showed SP- and CGRP-positive nerve terminals in the epidermal basal layer of the prepuce and frenulum in adult human males. The majority of the nerve terminals presented as bundles of different lengths and a few as enlarged nodosities. The density of SP- and CGRP-immunopositive nerve terminals in the preputial frenulum was significantly higher than those in the penis prepuce (P<0.01). Fluoro-Gold (FG) retrograde tracing method was used to trace the origin of nerve terminals in Sprague-Dawley rats. SP and CGRP immunofluorescence labeling was employed to detect the distribution of SP- and CGRP-immunoreactive neurons in DRG. FG retro-labeled neurons were localized in L(6) -DRG and S(1) -DRG. All the FG/SP and FG/CGRP double-labeled neurons were medium or small-sized. One-third of the FG-labeled neurons were SP-immunoreactive, and a half of them CGRP-immunoreactive in L(6) -DRG and S(1) -DRG, respectively. The FG/SP/CGRP-labeled neurons accounted for one fifth of the FG retro-labeled neurons. Taken together, these data suggest that the SP- and CGRP-immunopositive nerve fibers may participate in the transmission of afferent sensation in the preputial frenulum.

MeSH terms

  • Adult
  • Animals
  • Calcitonin Gene-Related Peptide / metabolism*
  • Fluorescent Antibody Technique
  • Ganglia, Spinal / cytology
  • Ganglia, Spinal / metabolism*
  • Humans
  • Male
  • Nerve Fibers / metabolism
  • Neurons, Afferent / cytology
  • Neurons, Afferent / metabolism*
  • Penis / innervation*
  • Rats
  • Rats, Sprague-Dawley
  • Sensation / physiology*
  • Substance P / metabolism*
  • Young Adult


  • Substance P
  • Calcitonin Gene-Related Peptide