Helene Gelez1, Sarah Poirier2, Patricia Facchinetti3, Kelly A Allers4, Chris Wayman5, Laurent Alexandre2, François Giuliano6. 1. Pelvipharm Laboratories, Orsay parc, Bâtiment Cèdres, ORSAY, France. Electronic address: h.gelez@pelvipharm.com. 2. Pelvipharm Laboratories, Orsay parc, Bâtiment Cèdres, ORSAY, France. 3. Centre de Psychiatrie et de Neurosciences Broca, Sainte-Anne, Paris, France. 4. Boehringer Ingelheim Pharma GmbH & Co. KG, CNS Disorders, Biberach an der Riss, Germany. 5. Pfizer Global Research and Development, Discovery Biology (432), Ramsgate Road, Sandwich, Kent, United Kingdom. 6. Pelvipharm Laboratories, Orsay parc, Bâtiment Cèdres, ORSAY, France; Raymond Poincaré Hospital Neuro-Uro-Andrology, Department of Physical Medicine and Rehabilitation, AP-HP, 92380 Garches, University of Versailles Saint Quentin, Paris, France.
Abstract
INTRODUCTION: The clitoris and the vagina are the main peripheral anatomical structures involved in physiological changes related to sexual arousal and orgasm. Their efferent control and, more particularly, the neurochemical phenotype of these descending neuronal pathways remain largely uncharacterized. AIM: To examine if brain neurons involved in the efferent control of the clitoris and the vagina possess melanocortin-4 receptor (MC4-R) and/or contain oxytocin (OT). METHODS: Neurons involved in the efferent control of the vagina and clitoris were identified following visualization of pseudorabies virus (PRV) retrograde tracing. PRV was injected into the vagina and clitoris in adult rats in estrous. On the fifth day postinjection, animals were humanely sacrificed, and brains were removed and sectioned, and processed for PRV visualization. The neurochemical phenotype of PRV-positive neurons was identified using double or triple immunocytochemical labeling against PRV, MC4-R, and OT. Double and triple labeling were quantified using confocal laser scanning microscopy. MAIN OUTCOME MEASURE: Neuroanatomical brain distribution, number and percentage of double-labeled PRV/MC4-R and PRV-/OT-positive neurons, and triple PRV-/MC4-R-/OT-labeled neurons. RESULTS: The majority of PRV immunopositive neurons which also expressed immunoreactivity for MC4-R were located in the paraventricular and arcuate nuclei of the hypothalamus. The majority of PRV positive neurons which were immunoreactive (IR) for OT were located in the paraventricular nucleus (PVN), medial preoptic area (MPOA), and lateral hypothalamus. PRV positive neurons were more likely to be IR for MC4-R than for OT. Scattered triple-labeled PRV/MC4-R/OT neurons were detected in the MPOA and the PVN. CONCLUSION: These data strongly suggest that MC4-R and, to a less extent, OT are involved in the efferent neuronal control of the clitoris and vagina, and consequently facilitate our understanding of how the melanocortinergic pathway regulates female sexual function.
INTRODUCTION: The clitoris and the vagina are the main peripheral anatomical structures involved in physiological changes related to sexual arousal and orgasm. Their efferent control and, more particularly, the neurochemical phenotype of these descending neuronal pathways remain largely uncharacterized. AIM: To examine if brain neurons involved in the efferent control of the clitoris and the vagina possess melanocortin-4 receptor (MC4-R) and/or contain oxytocin (OT). METHODS: Neurons involved in the efferent control of the vagina and clitoris were identified following visualization of pseudorabies virus (PRV) retrograde tracing. PRV was injected into the vagina and clitoris in adult rats in estrous. On the fifth day postinjection, animals were humanely sacrificed, and brains were removed and sectioned, and processed for PRV visualization. The neurochemical phenotype of PRV-positive neurons was identified using double or triple immunocytochemical labeling against PRV, MC4-R, and OT. Double and triple labeling were quantified using confocal laser scanning microscopy. MAIN OUTCOME MEASURE: Neuroanatomical brain distribution, number and percentage of double-labeled PRV/MC4-R and PRV-/OT-positive neurons, and triple PRV-/MC4-R-/OT-labeled neurons. RESULTS: The majority of PRV immunopositive neurons which also expressed immunoreactivity for MC4-R were located in the paraventricular and arcuate nuclei of the hypothalamus. The majority of PRV positive neurons which were immunoreactive (IR) for OT were located in the paraventricular nucleus (PVN), medial preoptic area (MPOA), and lateral hypothalamus. PRV positive neurons were more likely to be IR for MC4-R than for OT. Scattered triple-labeled PRV/MC4-R/OT neurons were detected in the MPOA and the PVN. CONCLUSION: These data strongly suggest that MC4-R and, to a less extent, OT are involved in the efferent neuronal control of the clitoris and vagina, and consequently facilitate our understanding of how the melanocortinergic pathway regulates female sexual function.
Authors: Davelene D Israel; Sharone Sheffer-Babila; Carl de Luca; Young-Hwan Jo; Shun Mei Liu; Qiu Xia; Daniel J Spergel; Siok L Dun; Nae J Dun; Streamson C Chua Journal: Endocrinology Date: 2012-03-09 Impact factor: 4.736
Authors: Denis Richard; Boris Monge-Roffarello; Kanta Chechi; Sébastien M Labbé; Eric E Turcotte Journal: Front Endocrinol (Lausanne) Date: 2012-02-27 Impact factor: 5.555