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Control of spinal motoneurones involved in eliminative and sexual functions by vasopressin and acetycholine: a morphological and electrophysiological approach

English title Control of spinal motoneurones involved in eliminative and sexual functions by vasopressin and acetycholine: a morphological and electrophysiological approach
Applicant Tribollet Eliane
Number 103890
Funding scheme Project funding (Div. I-III)
Research institution Dépt des Neurosciences Fondamentales Faculté de Médecine Université de Genève
Institution of higher education University of Geneva - GE
Main discipline Neurophysiology and Brain Research
Start/End 01.04.2004 - 31.03.2008
Approved amount 188'135.00
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Keywords (8)

Autoradiography; Brain slices; Erection; External sphincters; Immunocytochemisty; Patch clamp; Pudendal motoneurones; Retrograde labelling. spinal cord

Lay Summary (English)

Lead
Lay summary
Pudendal motoneurones innervate striated pelvic muscles involved in eliminative and sexual functions. In most mammalian species including the human, pudendal motoneurones are located in a single cell group, the nucleus of Onuf, whereas in rats, they are distributed in two distinct nuclei of the caudal lumbar spinal cord, the dorsomedial (DM) and dorsolateral (DL) nuclei. In male rats, DM motoneurons innervate the external anal sphincter and two muscles which contribute to penile rigidity during erection, the bulbocavernosus and the levator ani, whereas DL motoneurones control the external urethral sphincter and one penile-related muscle, the ischiocavernosus. Pudendal motoneurones differ from other somatic motoneurones by their sexual dimorphism and the maintenance of developmental characteristics in adulthood. In particular, they harbour vasopressin receptors permanently in contrast with other somatic motoneurones where receptors to this neuropeptide are expressed only transiently during development or following axotomy in the adult. The aim of the project was to get a better understanding of the basic properties of pudendal motoneurones and to investigate their sensitivity to some neuroactive substances. By using an integrated approach combining morphological and electrophysiological techniques, we found that : a) vasopressin, tachykinins and acetylcholine caused a powerfull excitation of all pudendal motoneurones; b) vasopressin acted via vasopressin 1a (V1a), but not V1b, V2 or oxytocin receptors; c) tachykinins acted via neurokinin 1 (NK1), but not NK2 or NK3 receptors; and c) the response to acetylcholine was mediated by nicotinic heteromeric receptors in DM motoneurones and by a7-containing homomeric receptors in DL motoneurones. Since DM and DL motoneurones innervate two distinct groups of pelvic muscles, a difference in their nicotinic pharmacology may be clinically relevant, as it might allow a selective pharmacological intervention in view of influencing the activity of one or the other set of muscles.
Direct link to Lay Summary Last update: 21.02.2013

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Associated projects

Number Title Start Funding scheme
55332 Control of spinal motoneurones involved in eliminative and sexualfunctions by vasopressin and acetylcholine: a morphological and electrophysiological approach 01.04.1999 Project funding (Div. I-III)

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