title: Anatomical basis of the coordination between smooth and striated urethral and anal sphincters: loops of regulation between inferior hypogastric plexus and pudendal nerve. Immuno-histological study with 3D reconstruction.
abstract: OBJECTIVE
  (1) Describe both nervous pathways to the sphincters, and highlight the anatomical support of their coordination. (2) Obtain a 3D representation of this complex innervation system.
  
  
  METHODS
  A computer-assisted anatomical dissection technique was used. Serial histological sections were cut in the pelvis of four female human foetuses (aged 19-32 weeks of gestation). The sections were treated with conventional staining, and with seven different immunostainings. The sections were digitalized and, finally, a 3D representation was built from the corresponding images.
  
  
  RESULTS
  Myelinated and sensory fibres were detected at the inferior hypogastric plexus (IHP) level. Our analysis showed that most of the afferent sensory fibres come from the urinary and anal sphincters through the anterior and posterior branches of the IHP respectively. A highly positive nitrergic (anti-NOS1) and sensitive (anti-CGRP) labelling was found in the external layer of the urethral sphincter. The 3D representation allowed describing the two components of the innervation system. A sensory-motor regulation loop was found for both sphincters.
  
  
  CONCLUSIONS
  A 3D description of the components of both nervous pathways to the sphincters has been established. Our findings on the innervation of the sphincters tend to question the classical infra/supra levatorian muscle description. The coordinated work of the internal and external layers of the anal and urethral sphincter is probably mediated by multiple roles regulation.
authors.affiliation: Laboratory of Experimental Anatomy Faculty of Medicine Montpellier-Nîmes, University Montpellier, 30 rue Lunaret, 34090, Montpellier, France. martinmbertrand@yahoo.fr.|Visceral and Digestive Surgery Department, CHU de Nimes, University Montpellier 1, Nimes, France. martinmbertrand@yahoo.fr.
authors.forename: M M
authors.identifier: http://orcid.org/0000-0002-9367-9504
authors.initials: MM
authors.lastname: Bertrand
authors.affiliation: Laboratory of Anatomy Faculty of Medicine, University of Damascus, Damascus, Syria.
authors.forename: B
authors.initials: B
authors.lastname: Alsaid
authors.affiliation: Urology-Andrology Department, CHU de Nimes, University Montpellier 1, Nimes, France.
authors.forename: S
authors.initials: S
authors.lastname: Droupy
authors.affiliation: Laboratory of Experimental Anatomy Faculty of Medicine Montpellier-Nîmes, University Montpellier, 30 rue Lunaret, 34090, Montpellier, France.|Visceral and Digestive Surgery Department, CHU de Nimes, University Montpellier 1, Nimes, France.
authors.forename: J
authors.initials: J
authors.lastname: Ripoche
authors.affiliation: Laboratory of Experimental Surgery, EA 4122, Faculty of Medicine, Bicêtre-Paris 11 University, Le Kremlin-Bicêtre, France.
authors.forename: G
authors.initials: G
authors.lastname: Benoit
authors.affiliation: Aix-Marseille Université, CNRS, EFS, ADES UMR 7268, 13916, Marseille, France.
authors.forename: P
authors.initials: P
authors.lastname: Adalian
authors.affiliation: Department of Digestive Surgery, Hôpital Nord, Aix-Marseille Université, Chemin des Bourrely, 13915, Marseille Cedex 20, France.
authors.forename: C
authors.initials: C
authors.lastname: Brunet
authors.affiliation: Service de médecine légale droit de la Santé-Aix-Marseille université UMR 7268 ADES, 13344, Marseille Cedex 15, France.
authors.forename: M D
authors.initials: MD
authors.lastname: Piercecchi-Marti
authors.affiliation: Laboratory of Experimental Anatomy Faculty of Medicine Montpellier-Nîmes, University Montpellier, 30 rue Lunaret, 34090, Montpellier, France.|Visceral and Digestive Surgery Department, CHU de Nimes, University Montpellier 1, Nimes, France.
authors.forename: M
authors.initials: M
authors.lastname: Prudhomme
mesh_terms: D001003:Anal Canal / Q000196:embryology* / Q000294:innervation; D004525:Efferent Pathways / Q000033:anatomy & histology; D005260:Female; D005333:Fetus / Q000033:anatomy & histology; D006801:Humans; D007001:Hypogastric Plexus / Q000196:embryology; D021621:Imaging, Three-Dimensional; D060525:Pudendal Nerve / Q000033:anatomy & histology; D014521:Urethra / Q000196:embryology* / Q000294:innervation
keywords: Anal sphincter; Immunohistochemistry; Inferior hypogastric plexus; Urinary sphincter