Fig. 3: Krause corpuscle afferents project to the dorsomedial spinal cord.

a,b, Retrograde labelling of DRG neurons innervating the clitoris (a) or penis (b) and the adjacent midline hairy skin region using CTB tracers conjugated to different fluorophores (hairy: CTB-488; genital: CTB-546). Coronal sections of the upper sacral spinal cord are shown on the right. c,d Labelling of Krause corpuscle afferents using injection of AAV2-retro-hSyn-FlpO into the clitoris (c) or glans penis (d) of TrkB^creER;R26^{FSF-LSL-Tdtomato} (tamoxifen, 0.5 mg at P5) or Ret^creER;R26^{FSF-LSL-TdTomato} (tamoxifen, 3 mg at E12.5) mice, with IB4 staining to label the lamina II of the spinal cord as a reference for laminar location. Similar results were observed in more than three animals per condition. For a–d, scale bars, 200 µm. The diagrams in a and b were created by G. Park.