Retrograde endocannabinoid signalling via type-1 cannabinoid receptor (CB1) expressed in neuronal afferents of gonadotropin-releasing hormone (GnRH) neurons of the mouse brain

Abstract

Event Abstract Back to Event Retrograde endocannabinoid signalling via type-1 cannabinoid receptor (CB1) expressed in neuronal afferents of gonadotropin-releasing hormone (GnRH) neurons of the mouse brain Imre Farkas1*, Levente Deli1, Imre Kalló1, Erik Hrabovszky1, Csaba Fekete1, Suzanne M. Moenter2, Masahiko Watanabe3 and Zsolt Liposits1 1 Institute of Experimental Medicine, Hungarian Academy of Science, Department of Endocrine Neurobiology, Hungary 2 University of Virginia, Neuroscience Graduate Program , Departments of Medicine and Cell Biology, United States 3 Hokkaido University, School of Medicine, Department of Anatomy, Japan Cannabinoids have been shown to alter GnRH secretion and inhibit gonadal functions at the hypothalamic level. Immunocytochemistry demonstrated presence of CB1 in nerve fibers in the medial preoptic area (MPOA) and the organum vasculosum of the lamina terminalis (OVLT). In the present study, light and electron microscopic double labeling experiments demonstrated the apposition of CB1-immunoreactive nerve terminals to the dendrites and perikarya of fusiform GnRH neurons residing in the MPOA-OVLT region. Whole cell clamp recordings - carried out on acute preoptic slices of male GnRH-GFP transgenic mice - revealed GABA-A receptor-mediated miniature postsynaptic currents (mPSCs) in GnRH neurons. The administration of the CB1 agonist WIN55,212 (1 μM) significantly decreased the frequency (49.0 ± 10.79 % of the control, p<0.05, n=10) and increased the amplitude of the mPSCs (120.4 ± 5.44 %, p<0.05). The pre-incubation of slices with the CB1 antagonist AM251 (1 μM; 15 min before applying WIN55,212) prevented the effect of WIN55,212 (105.6 ± 8.08 % of the amplitude and 109.0 ± 20.90 % of the frequency of the AM251-control mPSCs, n=8). When AM251 was applied alone, the frequency of the mPSCs increased (162.8 ± 26.4 % of the control, p<0.05, n=9), however, their amplitude did not change (100.3 ± 8.23 %). The data suggest that endogenous cannabinoids released from GnRH neurons exert local and partly tonical actions on the afferent inputs to GnRH neurons via retrograde signalling utilizing CB1 present in the presynaptic GABAergic elements. Supported by grants from the EU FWP 6 (LSHM-CT-2003-503041) and OTKA (T73002). Conference: 12th Meeting of the Hungarian Neuroscience Society, Budapest, Hungary, 22 Jan - 24 Jan, 2009. Presentation Type: Poster Presentation Topic: Homeostatic regulatory mechanisms Citation: Farkas I, Deli L, Kalló I, Hrabovszky E, Fekete C, Moenter SM, Watanabe M and Liposits Z (2009). Retrograde endocannabinoid signalling via type-1 cannabinoid receptor (CB1) expressed in neuronal afferents of gonadotropin-releasing hormone (GnRH) neurons of the mouse brain. Front. Syst. Neurosci. Conference Abstract: 12th Meeting of the Hungarian Neuroscience Society. doi: 10.3389/conf.neuro.01.2009.04.010 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 25 Feb 2009; Published Online: 25 Feb 2009. * Correspondence: Imre Farkas, Institute of Experimental Medicine, Hungarian Academy of Science, Department of Endocrine Neurobiology, Budapest, Hungary, farkas@koki.hu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Imre Farkas Levente Deli Imre Kalló Erik Hrabovszky Csaba Fekete Suzanne M Moenter Masahiko Watanabe Zsolt Liposits Google Imre Farkas Levente Deli Imre Kalló Erik Hrabovszky Csaba Fekete Suzanne M Moenter Masahiko Watanabe Zsolt Liposits Google Scholar Imre Farkas Levente Deli Imre Kalló Erik Hrabovszky Csaba Fekete Suzanne M Moenter Masahiko Watanabe Zsolt Liposits PubMed Imre Farkas Levente Deli Imre Kalló Erik Hrabovszky Csaba Fekete Suzanne M Moenter Masahiko Watanabe Zsolt Liposits Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.