Volume 47, Issue 5, Pages 627-634 (May 2005) Innervation of the Female Human Urethral Sphincter: 3D Reconstruction of Immunohistochemical Studies in the Fetus  Ibrahim Karam, Stéphane Droupy, Issam Abd-Alsamad, Jean-François Uhl, Gérard Benoît, Vincent Delmas  European Urology  Volume 47, Issue 5, Pages 627-634 (May 2005) DOI: 10.1016/j.eururo.2005.01.001 Copyright © 2005 Elsevier B.V. Terms and Conditions

Fig. 1 Nervous fibers identified by neuronal immunolabeling at the proximal third of urethra. Fibers run in the periurethral connective tissue and penetrate into the smooth muscle fibers at 4 o’clock and at 8 o’clock (arrows). The section was scanned at a resolution of 2800dots/inch at 598 colours. European Urology 2005 47, 627-634DOI: (10.1016/j.eururo.2005.01.001) Copyright © 2005 Elsevier B.V. Terms and Conditions

Fig. 2 A. Horizontal section of the proximal third of the urethra, showing unmyelinated nerve fibers at 12 o’clock (arrow). B. Nervous fibers identified by Luxol Fast Blue (×20): myelinated nerve fibers (red arrow) accompanying the unmyelinated fibers (black arrow). European Urology 2005 47, 627-634DOI: (10.1016/j.eururo.2005.01.001) Copyright © 2005 Elsevier B.V. Terms and Conditions

Fig. 3 Transverse sections at the middle third of female fetal urethra, 24th week of gestation (CRL 227mm). (A) presenting the nervous fibers of the striated sphincter (immunolabeling by PS100). (B) Another section, in 4μm of interval, stained by LFB confirms that these fibers are myelinated. These myelinated (somatic) fibers penetrate into striated muscle fibers at 3 o’clock and at 9 o’clock) (arrows). The sections were scanned directly at a resolution of 2800dots/inch at 598 colours. European Urology 2005 47, 627-634DOI: (10.1016/j.eururo.2005.01.001) Copyright © 2005 Elsevier B.V. Terms and Conditions

Fig. 4 At 3 o’clock on the image B (Fig. 3) the myelin sheath is blue-green (arrow), the background is colourless, and nuclei are red (magnification 40). European Urology 2005 47, 627-634DOI: (10.1016/j.eururo.2005.01.001) Copyright © 2005 Elsevier B.V. Terms and Conditions

Fig. 5 Schematic representation of female urethral sphincter. Left lateral view. AN, autonomic nerves; PP, pelvic plexus; PN, pudendal nerve; DNC, dorsal nerve of the clitoris; IPP, intrapelvic pathway (supralevator); EPP, extrapelvic pathway (infralevator). European Urology 2005 47, 627-634DOI: (10.1016/j.eururo.2005.01.001) Copyright © 2005 Elsevier B.V. Terms and Conditions

Fig. 6 Three-dimensional reconstruction from transverse sections of a 18-week old fetus (CRL 160mm). (A) The connective tissue surrounding all the reconstructed structures (in cyan), (B) and (C). The lateral and anterior vaginal walls (in magenta) (D). The smooth muscles, in blue, surrounding the submucousa (in cyan), (E) the striated muscles, in red, forming complete circles in the 2nd third of urethra and incomplete in the distal third (arrows). (F), (G) and (H) represent the relation between the smooth and striated muscular structures. European Urology 2005 47, 627-634DOI: (10.1016/j.eururo.2005.01.001) Copyright © 2005 Elsevier B.V. Terms and Conditions

Fig. 7 Three-dimensional reconstruction from transverse sections of a 40-week old fetus (CRL 340mm). (A) Represents the unmyelinated nervous fibers of the proximal third of urethra (in yellow), located mainly at 4 o’clock, 8 o’clock and 12 o’clock, associated to myelinated nervous fibers (in green), which run on the posterior surface of the urethra up to the striated sphincter. (B) The periurethral tissue is made transparent to show the unmyelinated nerves and their distribution on the urethra. (C) and (D) Show that the majority of these unmyelinated nerves run along the walls of vagina (between the posterior surface of the urethra and the anterior vaginal wall). European Urology 2005 47, 627-634DOI: (10.1016/j.eururo.2005.01.001) Copyright © 2005 Elsevier B.V. Terms and Conditions

Fig. 8 Three-dimensional reconstruction from transverse sections of a 20-week old fetus (CRL 187mm). (A), (B) and (C). Show the myelinated nerves which approach the striated sphincter, mainly, at 3 and at 9 o’clock but also at 1 o’clock, and by its posterior surface. (D), (E) The smooth muscle is in transparency to show the myelinated fibers, which reach the external part of the smooth muscle (arrows). (F) The striated muscle is in transparency to show the penetration of nervous myelinated fibers in the external layer of the smooth muscle on its lateral surfaces where it is intermingled with the striated muscle (arrows). European Urology 2005 47, 627-634DOI: (10.1016/j.eururo.2005.01.001) Copyright © 2005 Elsevier B.V. Terms and Conditions