title: Medial Preoptic Regulation of the Ventral Tegmental Area Related to the Control of Sociosexual Behaviors.
abstract: During sociosexual encounters, different brain mechanisms interact to orchestrate information about the salience of external stimuli along with the current physiological and environmental conditions in order to process these in an optimal manner. One candidate neural system involves the potential interplay between the medial preoptic nucleus (POM) and mesolimbic reward circuitry. We present here evidence indicating that projections originating from the POM play a modulatory role on the mesolimbic reward circuitry related to male sexual behavior in Japanese quail (Coturnix japonica). First, we used an asymmetrical inactivation strategy where POM and ventral tegmental area (VTA) were unilaterally inactivated via the GABAAagonist muscimol, either in an ipsilateral or contralateral fashion. Ipsilateral injections of muscimol had negligible effects on both appetitive and consummatory sexual behaviors. In contrast, contralateral injections significantly impaired appetitive sexual behaviors but had no clear effect on consummatory sexual behaviors. Next, we labeled cells projecting from the POM to the VTA by stereotaxic injection into VTA of the retrograde tracer biotinylated dextran amine (BDA). Two weeks later, brains from males who had been allowed to interact freely with a female (15 min) or kept as controls were collected and fixed for double immunohistochemical labeling of BDA and the immediate early gene Fos. More retrogradely labeled BDA cells in POM expressed Fos after sociosexual interactions than in control conditions. Overall, these findings provide novel evidence for the interplay between POM and VTA in the modulation of appetitive but not consummatory sexual behaviors. Schematic representation of the putative role of the projection from the medial POM to the VTA in the regulation of appetitive and consummatory sexual behaviors. Unilateral inactivation of POM and VTA on (1) ipsilateral sides has negligible effects on both aspects of sexual behaviors, whereas (2) contralateral inactivation disrupts appetitive sexual behaviors.
authors.affiliation: Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, Maryland 21218; Department of Psychology, University of Maryland, College Park, College Park, Maryland 20742.
authors.forename: Onur
authors.initials: O
authors.lastname: Iyilikci
authors.affiliation: GIGA-Neurosciences, University of Liege , 4000 Liege, Belgium.
authors.forename: Jacques
authors.identifier: 0000-0001-9492-2126
authors.initials: J
authors.lastname: Balthazart
authors.affiliation: Department of Psychology, University of Maryland, College Park , College Park, Maryland 20742.
authors.forename: Gregory F
authors.identifier: 0000-0002-4784-0520
authors.initials: GF
authors.lastname: Ball
mesh_terms: D000818:Animals; D001070:Appetitive Behavior / Q000502:physiology; D030161:Avian Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D001710:Biotin / Q000031:analogs & derivatives; D002408:Catheters, Indwelling; D003370:Coturnix; D003911:Dextrans; D007839:Functional Laterality; D058785:GABA-A Receptor Agonists / Q000494:pharmacology; D007150:Immunohistochemistry; D008297:Male; D009118:Muscimol / Q000494:pharmacology; D009434:Neural Pathways / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D056347:Neuroanatomical Tract-Tracing Techniques; D056325:Neuronal Tract-Tracers; D011301:Preoptic Area / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D011963:Receptors, GABA-A / Q000378:metabolism; D012726:Sexual Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D012919:Social Behavior; D017557:Ventral Tegmental Area / Q000166:cytology / Q000187:drug effects / Q000502:physiology*
chemical_list: D030161:Avian Proteins; D003911:Dextrans; D058785:GABA-A Receptor Agonists; D056325:Neuronal Tract-Tracers; D016760:Proto-Oncogene Proteins c-fos; D011963:Receptors, GABA-A; C076397:biotinylated dextran amine; D009118:Muscimol; D001710:Biotin
keywords: medial preoptic nucleus; mesolimbic system; social behavior; sociosexual behavior