The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
Jacques Balthazart - One of the best experts on this subject based on the ideXlab platform.
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Male Sexual Behavior and Hormones in Non-Mammalian Vertebrates
Encyclopedia of Animal Behavior, 2020Co-Authors: Jacques Balthazart, Gregory F. BallAbstract:In most vertebrate species, Male Sexual Behavior is activated by the action of testosterone on the preoptic area and in many cases this Behavioral activation requires transformation of the steroid into estradiol and 5α-dihydrotestosterone. These metabolites, either alone or in synergy, act at the cellular level to produce changes in neuronal function that mediate Behavioral changes. Variation in plasma testosterone concentrations does not simply correlate in a positive manner with the degree of Behavioral activation. For example, in many species, testosterone cannot activate Male-typical Sexual Behaviors in feMales. This sex difference in the Behavioral consequences of testosterone results from organizational effects of sex steroids that irreversibly differentiate the brain during ontogeny so that Male brains will respond in adulthood to testosterone while feMale brains will not. Behavioral effects of testosterone are largely mediated by changes in the transcription of specific proteins, including enzymes that synthesize or catabolize neurotransmitters and their receptors. These changes in protein expression in turn produce changes in neurotransmission in a defined neuronal circuitry that supports Behavior expression. There are more recently described effects of steroids that do not involve protein transcription but rather involve actions at the neuronal membrane or direct changes in intracellular signaling cascades that also seem to contribute to the control of Male Sexual Behavior. These principles seem to apply to a wide range of non-mammalian vertebrate species though a number of specialized reproductive strategies that could be associated with exceptions to these general rules have also been described.
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Modulation of testosterone-dependent Male Sexual Behavior and the associated neuroplasticity
General and Comparative Endocrinology, 2013Co-Authors: Thierry Charlier, Aurore L. Seredynski, Neville-andrew Niessen, Jacques BalthazartAbstract:Steroids modulate the transcription of a multitude of genes and ultimately influence numerous aspects of reproductive Behaviors. Our research investigates how one single steroid, testosterone, is able to trigger this vast number of physiological and Behavioral responses. Testosterone potency can be changed locally via aromatization into 17β-estradiol which then activates estrogen receptors of the alpha and beta sub-types. We demonstrated that the independent activation of either receptor activates different aspects of Male Sexual Behavior in Japanese quail. In addition, several studies suggest that the specificity of testosterone action on target genes transcription is related to the recruitment of specific steroid receptor coactivators. We demonstrated that the specific down-regulation of the coactivators SRC-1 or SRC-2 in the medial preoptic nucleus by antisense techniques significantly inhibits steroid-dependent Male-typical copulatory Behavior and the underlying neuroplasticity. In conclusion, our results demonstrate that the interaction between several steroid metabolizing enzymes, steroid receptors and their coactivators plays a key role in the control of steroid-dependent Male Sexual Behavior and the associated neuroplasticity in quail.
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Steroid receptor coactivator 2 modulates steroid-dependent Male Sexual Behavior and neuroplasticity in Japanese quail (Coturnix japonica)
Journal of Neurochemistry, 2011Co-Authors: Neville-andrew Niessen, Gregory F. Ball, Jacques Balthazart, Thierry CharlierAbstract:J. Neurochem. (2011) 119, 579–593. Abstract Steroid receptor coactivators are necessary for efficient transcriptional regulation by ligand-bound nuclear receptors, including estrogen and androgen receptors. Steroid receptor coactivator-2 (SRC-2) modulates estrogen- and progesterone-dependent Sexual Behavior in feMale rats but its implication in the control of Male Sexual Behavior has not been studied to our knowledge. We cloned and sequenced the complete quail SRC-2 transcript and showed by semi-quantitative PCR that SRC-2 expression is nearly ubiquitous, with high levels of expression in the kidney, cerebellum and diencephalon. Real-time quantitative PCR did not reveal any differences between intact Males and feMales the medial preoptic nucleus (POM), optic lobes and cerebellum. We next investigated the physiological and Behavioral role of this coactivator using in vivo antisense oligonucleotide techniques. Daily injections in the third ventricle at the level of the POM of locked nucleic acid antisense targeting SRC-2 significantly reduced the expression of testosterone-dependent Male-typical copulatory Behavior but no inhibition of one aspect of the appetitive Sexual Behavior was observed. The volume of POM, defined by aromatase-immunoreactive cells, was markedly decreased in animals treated with antisense as compared with controls. These results demonstrate that SRC-2 plays a prominent role in the control of steroid-dependent Male Sexual Behavior and its associated neuroplasticity in Japanese quail.
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specific activation of estrogen receptor alpha and beta enhances Male Sexual Behavior and neuroplasticity in Male japanese quail
PLOS ONE, 2011Co-Authors: Aurore Seredynski, Gregory F. Ball, Jacques Balthazart, Thierry CharlierAbstract:Two subtypes of estrogen receptors (ER), ERα and ERβ, have been identified in humans and numerous vertebrates, including the Japanese quail. We investigated in this species the specific role(s) of each receptor in the activation of Male Sexual Behavior and the underlying estrogen-dependent neural plasticity. Castrated Male Japanese quail received empty (CX) or testosterone-filled (T) implants or were daily injected with the ER general agonist diethylstilbestrol (DES), the ERα-specific agonist PPT, the ERβ-specific agonist DPN or the vehicle, propylene glycol. Three days after receiving the first treatment, subjects were alternatively tested for appetitive (rhythmic cloacal sphincter movements, RCSM) and consummatory aspects (copulatory Behavior) of Male Sexual Behavior. 24 hours after the last Behavioral testing, brains were collected and analyzed for aromatase expression and vasotocinergic innervation in the medial preoptic nucleus. The expression of RCSM was activated by T and to a lesser extent by DES and PPT but not by the ERβagonist DPN. In parallel, T fully restored the complete sequence of copulation, DES was partially active and the specific activation of ERα or ERβ only resulted in a very low frequency of mount attempts in few subjects. T increased the volume of the medial preoptic nucleus as measured by the dense cluster of aromatase-immunoreactive cells and the density of the vasotocinergic innervation within this nucleus. DES had only a weak action on vasotocinergic fibers and the two specific ER agonists did not affect these neural responses. Simultaneous activation of both receptors or treatments with higher doses may be required to fully activate Sexual Behavior and the associated neurochemical events.
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Differential effects of central injections of D1 and D2 receptor agonists and antagonists on Male Sexual Behavior in Japanese quail
European Journal of Neuroscience, 2010Co-Authors: Hayley K. Kleitz-nelson, Jacques Balthazart, Charlotte A. Cornil, Gregory F. BallAbstract:A key brain site in the control of Male Sexual Behavior is the medial preoptic area (mPOA) where dopamine stimulates both D1 and D2 receptor subtypes. Research completed to date in Japanese quail has only utilized systemic injections, so much is unknown about the specific role played by dopamine in the brain and mPOA in particular. The present study investigates the role of D1 and D2 receptors on Male Sexual Behavior by examining how intracerebroventricular (ICV) injections and microinjections into the mPOA of D1 and D2 agonists and antagonists influence appetitive and consummatory aspects of Sexual Behavior in Male quail. Experiments 1 and 2 investigate the effects of ICV injections at three doses of D1 or D2 agonists and antagonists. Results indicate that D1 receptors facilitate consummatory Male Sexual Behavior while D2 receptors inhibit both appetitive and consummatory Behaviors. Experiment 3 examines the effects of the same compounds specifically injected in the mPOA and shows that in this region, both receptors stimulate Male Sexual Behaviors. Together, these data indicate that the stimulatory action of dopamine in the mPOA may require a combined activation of D1 and D2 receptors. Finally, the regulation of Male Sexual Behavior by centrally infused dopaminergic compounds in a species lacking an intromittent organ suggests that dopamine action on Male Sexual Behavior does not simply reflect the modulation of genital reflexes due to general arousal, but relates to the central control of Sexual motivation. Together, these data support the claim that dopamine specifically regulates Male Sexual Behavior.
Gregory F. Ball - One of the best experts on this subject based on the ideXlab platform.
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Male Sexual Behavior and Hormones in Non-Mammalian Vertebrates
Encyclopedia of Animal Behavior, 2020Co-Authors: Jacques Balthazart, Gregory F. BallAbstract:In most vertebrate species, Male Sexual Behavior is activated by the action of testosterone on the preoptic area and in many cases this Behavioral activation requires transformation of the steroid into estradiol and 5α-dihydrotestosterone. These metabolites, either alone or in synergy, act at the cellular level to produce changes in neuronal function that mediate Behavioral changes. Variation in plasma testosterone concentrations does not simply correlate in a positive manner with the degree of Behavioral activation. For example, in many species, testosterone cannot activate Male-typical Sexual Behaviors in feMales. This sex difference in the Behavioral consequences of testosterone results from organizational effects of sex steroids that irreversibly differentiate the brain during ontogeny so that Male brains will respond in adulthood to testosterone while feMale brains will not. Behavioral effects of testosterone are largely mediated by changes in the transcription of specific proteins, including enzymes that synthesize or catabolize neurotransmitters and their receptors. These changes in protein expression in turn produce changes in neurotransmission in a defined neuronal circuitry that supports Behavior expression. There are more recently described effects of steroids that do not involve protein transcription but rather involve actions at the neuronal membrane or direct changes in intracellular signaling cascades that also seem to contribute to the control of Male Sexual Behavior. These principles seem to apply to a wide range of non-mammalian vertebrate species though a number of specialized reproductive strategies that could be associated with exceptions to these general rules have also been described.
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Steroid receptor coactivator 2 modulates steroid-dependent Male Sexual Behavior and neuroplasticity in Japanese quail (Coturnix japonica)
Journal of Neurochemistry, 2011Co-Authors: Neville-andrew Niessen, Gregory F. Ball, Jacques Balthazart, Thierry CharlierAbstract:J. Neurochem. (2011) 119, 579–593. Abstract Steroid receptor coactivators are necessary for efficient transcriptional regulation by ligand-bound nuclear receptors, including estrogen and androgen receptors. Steroid receptor coactivator-2 (SRC-2) modulates estrogen- and progesterone-dependent Sexual Behavior in feMale rats but its implication in the control of Male Sexual Behavior has not been studied to our knowledge. We cloned and sequenced the complete quail SRC-2 transcript and showed by semi-quantitative PCR that SRC-2 expression is nearly ubiquitous, with high levels of expression in the kidney, cerebellum and diencephalon. Real-time quantitative PCR did not reveal any differences between intact Males and feMales the medial preoptic nucleus (POM), optic lobes and cerebellum. We next investigated the physiological and Behavioral role of this coactivator using in vivo antisense oligonucleotide techniques. Daily injections in the third ventricle at the level of the POM of locked nucleic acid antisense targeting SRC-2 significantly reduced the expression of testosterone-dependent Male-typical copulatory Behavior but no inhibition of one aspect of the appetitive Sexual Behavior was observed. The volume of POM, defined by aromatase-immunoreactive cells, was markedly decreased in animals treated with antisense as compared with controls. These results demonstrate that SRC-2 plays a prominent role in the control of steroid-dependent Male Sexual Behavior and its associated neuroplasticity in Japanese quail.
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specific activation of estrogen receptor alpha and beta enhances Male Sexual Behavior and neuroplasticity in Male japanese quail
PLOS ONE, 2011Co-Authors: Aurore Seredynski, Gregory F. Ball, Jacques Balthazart, Thierry CharlierAbstract:Two subtypes of estrogen receptors (ER), ERα and ERβ, have been identified in humans and numerous vertebrates, including the Japanese quail. We investigated in this species the specific role(s) of each receptor in the activation of Male Sexual Behavior and the underlying estrogen-dependent neural plasticity. Castrated Male Japanese quail received empty (CX) or testosterone-filled (T) implants or were daily injected with the ER general agonist diethylstilbestrol (DES), the ERα-specific agonist PPT, the ERβ-specific agonist DPN or the vehicle, propylene glycol. Three days after receiving the first treatment, subjects were alternatively tested for appetitive (rhythmic cloacal sphincter movements, RCSM) and consummatory aspects (copulatory Behavior) of Male Sexual Behavior. 24 hours after the last Behavioral testing, brains were collected and analyzed for aromatase expression and vasotocinergic innervation in the medial preoptic nucleus. The expression of RCSM was activated by T and to a lesser extent by DES and PPT but not by the ERβagonist DPN. In parallel, T fully restored the complete sequence of copulation, DES was partially active and the specific activation of ERα or ERβ only resulted in a very low frequency of mount attempts in few subjects. T increased the volume of the medial preoptic nucleus as measured by the dense cluster of aromatase-immunoreactive cells and the density of the vasotocinergic innervation within this nucleus. DES had only a weak action on vasotocinergic fibers and the two specific ER agonists did not affect these neural responses. Simultaneous activation of both receptors or treatments with higher doses may be required to fully activate Sexual Behavior and the associated neurochemical events.
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A Comparative Approach to the Study of Dopamine and Male Sexual Behavior: What Can Japanese Quail Teach Us? A Reply to Pfaus (2010)
Behavioral Neuroscience, 2010Co-Authors: Hayley K. Kleitz-nelson, Juan M Dominguez, Gregory F. BallAbstract:One of the most robust findings about dopamine (DA) is that the stimulation of dopaminergic systems promotes the activation of Male Sexual Behavior. The commentary by Pfaus (2010) included a thorough review of studies of DA and Male Sexual Behavior. We agree with him that the release of DA in the preoptic region in Male quail in response to feMales and in association with the exhibition of Male Sexual Behavior appears to be highly conserved and that it seems to have evolved very early in the evolutionary history of the vertebrate brain. However, additional data have been collected indicating that there may be significant species differences in the dopaminergic regulation of Male Behavior in quail compared with rats. In this response, we take the opportunity to make a few broader points about DA and Male Sexual Behavior in light of other studies that have been conducted in birds and introduce some interesting taxonomic variation that is still not well understood.
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Differential effects of central injections of D1 and D2 receptor agonists and antagonists on Male Sexual Behavior in Japanese quail
European Journal of Neuroscience, 2010Co-Authors: Hayley K. Kleitz-nelson, Jacques Balthazart, Charlotte A. Cornil, Gregory F. BallAbstract:A key brain site in the control of Male Sexual Behavior is the medial preoptic area (mPOA) where dopamine stimulates both D1 and D2 receptor subtypes. Research completed to date in Japanese quail has only utilized systemic injections, so much is unknown about the specific role played by dopamine in the brain and mPOA in particular. The present study investigates the role of D1 and D2 receptors on Male Sexual Behavior by examining how intracerebroventricular (ICV) injections and microinjections into the mPOA of D1 and D2 agonists and antagonists influence appetitive and consummatory aspects of Sexual Behavior in Male quail. Experiments 1 and 2 investigate the effects of ICV injections at three doses of D1 or D2 agonists and antagonists. Results indicate that D1 receptors facilitate consummatory Male Sexual Behavior while D2 receptors inhibit both appetitive and consummatory Behaviors. Experiment 3 examines the effects of the same compounds specifically injected in the mPOA and shows that in this region, both receptors stimulate Male Sexual Behaviors. Together, these data indicate that the stimulatory action of dopamine in the mPOA may require a combined activation of D1 and D2 receptors. Finally, the regulation of Male Sexual Behavior by centrally infused dopaminergic compounds in a species lacking an intromittent organ suggests that dopamine action on Male Sexual Behavior does not simply reflect the modulation of genital reflexes due to general arousal, but relates to the central control of Sexual motivation. Together, these data support the claim that dopamine specifically regulates Male Sexual Behavior.
Elaine M. Hull - One of the best experts on this subject based on the ideXlab platform.
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1 – Male Sexual Behavior
Hormones brain and behavior, 2020Co-Authors: Elaine M. HullAbstract:Male Sexual Behavior comprises a complex pattern of genital and somatomotor responses. Hormones act via receptors in brain, spinal, and peripheral sites to bias sensory inputs and motor outputs to favor Sexual responsiveness. Copulation includes mounts, intromissions, and ejaculations, followed by Sexual quiescence. After 6–12 ejaculations, Male rats become Sexually satiated. Neural controls include chemosensory inputs via the main and accessory olfactory systems to the medial amygdala, which transmits information directly and indirectly to the medial preoptic area (mPOA), which integrates sensory and hormonal information and elicits genital reflexes and copulatory patterns and contributes to Sexual motivation. Genital sensory input arrives via the central tegmental field/dorsolateral tegmentum (including the subparafasicular nucleus) directly or indirectly into the mPOA. Output from the mPOA is via the paraventricular nucleus and midbrain and brainstem sites. The mesocorticolimbic dopamine pathway contributes motivational fervor, and neural programs for erection and ejaculation reside in the lumbosacral spinal cord. Dopamine facilitates Male Sexual Behavior, whereas serotonin (5HT) is largely inhibitory, although stimulation of 5-HT1A receptors facilitates ejaculation. Norepinephrine has both stimulatory and inhibitory effects on copulation, via α1- and α2-adrenoceptors, respectively. Endogenous opioids play a complex modulatory role in all aspects of copulation. The brain areas that regulate Male Sexual Behavior also influence other social Behaviors.
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influences of dopamine and glutamate in the medial preoptic area on Male Sexual Behavior
Pharmacology Biochemistry and Behavior, 2014Co-Authors: Ryan G Will, Elaine M. Hull, Juan M DominguezAbstract:Abstract Several brain nuclei interact to orchestrate the appetitive and consummatory aspects of Male Sexual Behavior. Of these structures, the medial preoptic area (mPOA) of the hypothalamus is of particular interest, as it receives input from all sensory modalities, and damage to this region disrupts copulation in a wide variety of taxa. Furthermore, the mPOA is both responsive to gonadal hormones and involved in endocrine regulation. Neurochemical studies have demonstrated that both dopamine and glutamate levels rise in the mPOA in response to Sexual activity, while antagonism of these neurotransmitters impairs Male Sexual response. Here we review how dopamine and glutamate act in the mPOA to modulate Male Sexual Behavior.
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oxytocin in the medial preoptic area facilitates Male Sexual Behavior in the rat
Hormones and Behavior, 2011Co-Authors: Renu Bhatt, Katie B Picotte, Elaine M. HullAbstract:Oxytocin (OT) is a versatile neuropeptide that is involved in a variety of mammalian Behaviors, and its role in reproductive function and Behavior has been well established. The majority of pharmacological studies of the effects of OT on Male Sexual Behavior have focused on the paraventricular nucleus (PVN), ventral tegmental area (VTA), hippocampus, and amygdala. Less attention has been given to the medial preoptic area (MPOA), a major integrative site for Male Sexual Behavior. The present study investigated the effects of intra-MPOA administration of OT and (d(CH2)51, Tyr(Me)2, Thr4, Orn8, Tyr-NH29)-vasotocin, an OT antagonist (OTA), on copulation in the Male rat. The relationship between OT receptor (OTR) binding levels in the MPOA and Sexual efficiency was also explored. Microinjection of OT into the MPOA facilitated copulation in Sexually experienced Male rats, whereas similar injections of an OTA inhibited certain aspects of copulation but had no significant effect on locomotor activity in an open field. Contrary to expectation, Sexually efficient Males had lower levels of OTR binding in the rostral MPOA compared to inefficient animals. The present data suggest that OT activity in the MPOA is not necessary for the expression of Male Sexual Behavior but is sufficient to facilitate copulatory Behaviors and improve Sexual efficiency in Sexually experienced Male rats. These data also suggest that OTR activity in the MPOA stimulates anogenital investigation, facilitates the initiation of copulation, and plays a role in the sensitization effect of the first ejaculation on subsequent ejaculations.
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a role for hypocretin orexin in Male Sexual Behavior
The Journal of Neuroscience, 2007Co-Authors: John W Muschamp, Juan M Dominguez, Satoru M Sato, Rohyu Shen, Elaine M. HullAbstract:The role of hypocretin (orexin; hcrt/orx) neurons in regulation of arousal is well established. Recently, hcrt/orx has been implicated in food reward and drug-seeking Behavior. We report here that in Male rats, Fos immunoreactivity (ir) in hcrt/orx neurons increases markedly during copulation, whereas castration produces decreases in hcrt/orx neuron cell counts and protein levels in a time course consistent with postcastration impairments in copulatory Behavior. This effect was reversed by estradiol replacement. Immunolabeling for androgen (AR) and estrogen (ERα) receptors revealed no colocalization of hcrt/orx with AR and few hcrt/orx neurons expressing ERα, suggesting that hormonal regulation of hcrt/orx expression is via afferents from neurons containing those receptors. We also demonstrate that systemic administration of the orexin-1 receptor antagonist SB 334867 [N-(2-methyl-6-benzoxazolyl)-N″-1,5-naphthyridin-4-yl urea] impairs copulatory Behavior. One locus for the proSexual effects of hcrt/orx may be the ventral tegmental area (VTA). We show here that hcrt-1/orx-A produces dose-dependent increases in firing rate and population activity of VTA dopamine (DA) neurons in vivo. Activation of hcrt/orx during copulation, and in turn, excitation of VTA DA neurons by hcrt/orx, may contribute to the robust increases in nucleus accumbens DA previously observed during Male Sexual Behavior. Subsequent triple immunolabeling in anterior VTA showed that Fos-ir in tyrosine hydroxylase-positive neurons apposed to hcrt/orx fibers increases during copulation. Together, these data support the view that hcrt/orx peptides may act in a steroid-sensitive manner to facilitate the energized pursuit of natural rewards like sex via activation of the mesolimbic DA system.
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preoptic glutamate facilitates Male Sexual Behavior
The Journal of Neuroscience, 2006Co-Authors: Juan M Dominguez, Elaine M. HullAbstract:The medial preoptic area (MPOA) is a critical regulatory site for the control of Male Sexual Behavior. We first measured glutamate in 2 min microdialysate samples from the MPOA before, during, and after copulation by Male rats. There was a slight [∼140% of baseline (BL)] rise in extracellular glutamate when the feMale was presented, a significant increase (∼170% of BL) during periods of mounting and intromitting, and a very large increase in samples collected during ejaculation (∼300% of BL). A precipitous fall in levels occurred in the first postejaculatory sample; the magnitude of this fall was highly correlated with the length of the postejaculatory interval of quiescence. In experiment 2, we reverse-dialyzed a mixture of glutamate uptake inhibitors into the MPOA before and during mating; control animals received artificial CSF. The mixture increased extracellular glutamate (∼280% of BL), increased the number of ejaculations in the 40 min test, decreased ejaculation latency, and decreased the postejaculatory latency to resume copulation. These data, together with other findings that glutamate in the MPOA can elicit genital reflexes in anesthetized rats and that glutamate receptor antagonists in the MPOA impair copulation, strongly suggest that MPOA glutamate is a major facilitator of copulation and that the postejaculatory fall in glutamate regulates the postejaculatory interval.
Berend Olivier - One of the best experts on this subject based on the ideXlab platform.
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pharmacological studies on the role of 5 ht1a receptors in Male Sexual Behavior of wildtype and serotonin transporter knockout rats
Frontiers in Behavioral Neuroscience, 2020Co-Authors: Diana Carolina Esquivelfranco, Sietse F De Boer, Marcel D Waldinger, Berend Olivier, Jocelien D A OlivierAbstract:Brain serotonin (5-HT) neurotransmission plays an important role in Male Sexual Behavior and it is well established that activating 5-HT1AR in rats facilitates ejaculatory Behavior. However, the relative contribution of 5-HT1A somatodendritic autoreceptors and heteroreceptors in this pro-Sexual Behavior is unclear. Moreover, it is unclear whether the contribution of somatodendritic 5-HT1A autoreceptors and postsynaptic 5-HT1A heteroreceptors alter when extracellular 5-HT levels are chronically increased. Serotonin transporter knockout (SERT-/-) rats exhibit enhanced extracellular 5-HT levels and desensitized 5-HT1A receptors. These rats model neurochemical changes underlying chronic SSRI-induced Sexual dysfunction. We want to determine the role of presynaptic versus postsynaptic 5-HT1A receptors in the pro-Sexual effects of 5-HT1A receptor agonists in SERT+/+ and in SERT-/- rats. Therefore, acute effects of the biased 5-HT1A receptor agonists F-13714, a preferential 5-HT1A autoreceptor agonist, or F-15599, a preferential 5-HT1A heteroreceptor agonist, and S15535 a mixed 5-HT1A autoreceptor agonist/heteroreceptor antagonist, on Male Sexual Behavior were assessed. A clear and stable genotype effect was found after training where SERT+/+ performed Sexual Behavior at a higher level than SERT-/- rats. Both F-15599 and F-13714 induced pro-Sexual activity in SERT+/+ and SERT-/- animals. Compared to SERT+/+, the F13714- dose-response curve in SERT-/- rats was shifted to the right. SERT+/+ and SERT-/- rats responded similar to F15599. Within both SERT+/+ and SERT-/- rats the potency of F-13714 was much stronger compared to F-15599. S15535 had no effect on Sexual Behavior in either genotype. In SERT+/+ and SERT-/- rats that were selected on comparable low Sexual activity (SERT+/+ 3 or less ejaculations and SERT-/- 5 or less ejaculations in 10 weeks) S15535 also did not influence Sexual Behavior. The two biased compounds with differential effects on 5-HT1A auto- and hetero-receptors, exerted pro-Sexual activity in both SERT+/+ and SERT-/- rats. Applying these specific pharmacological tools has not solved whether pre- or post-synaptic 5-HT1A receptors are involved in pro-Sexual activity. Moreover, the inactivity of S15535 in Male Sexual Behavior in either genotype was unexpected. The question is whether the in vivo pharmacological profile of the different 5-HT1A receptor ligands used, is sufficient to differentiate pre-and/or post-synaptic 5-HT1AR contributions in Male rat Sexual Behavior.
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the serotonin transporter plays an important role in Male Sexual Behavior a study in serotonin transporter knockout rats
The Journal of Sexual Medicine, 2011Co-Authors: Johnny S W Chan, Marcel D Waldinger, Berend Olivier, Eelke M S Snoeren, Edwin Cuppen, Ronald S OostingAbstract:ABSTRACT Introduction Serotonin (5‐HT) is an important neurotransmitter for Sexual Behaviors. Heterozygous (+/−) serotonin transporter (SERT) rats and SERT knockout rats (−/−) have serotonergic disturbances with significant elevations of basal extracellular 5‐HT levels. Aim To investigate the putative role of the SERT in Male Sexual Behavior. Methods After extensive Sexual training, the effects of the 5‐HT 1A/7 receptor agonist ±8‐OH‐DPAT, the 5‐HT 1A receptor antagonist WAY100 635 and a combination of both on Sexual Behaviors of SERT −/− and SERT +/− knockout and wildtype (SERT +/+ ) Male Wistar rats were examined. Main Outcome Measures Male rat Sexual Behaviors of mounts, intromissions, and ejaculations. Results SERT −/− had lower basal ejaculation frequencies than SERT +/− and SERT +/+ animals. ±8‐OH‐DPAT enhanced Sexual performance in all three genotypes to the same extent. WAY100635 dose‐dependently inhibited Sexual Behavior in all three genotypes with significant dose to genotype interactions. WAY100635 exerted the strongest effects in SERT −/− animals. The combination of a dose range of ±8‐OH‐DPAT and a selected dose of WAY100635 revealed only partial antagonism by ±8‐OH‐DPAT of the Sexual inhibitory effects of WAY100635. Conclusions. Absence of the serotonin transporter reduces basal ejaculatory performance in Male rats. Pharmacological experiments suggest that separate pools of 5‐HT 1A receptors regulate different aspects of Sexual performance in Male rats. 5‐HT 7 receptors may play a minor role in the partial recovery of Sexual Behavior after combination of ±8‐OH‐DPAT and WAY100635. The SERT −/− rat may be a model for chronic SSRI treatment, delayed ejaculation, anorgasmia, and/or low libido. Chan JSW, Snoeren EMS, Cuppen E, Waldinger MD, Olivier B, and Oosting RS. The serotonin transporter plays an important role in Male Sexual Behavior: A study in serotonin transporter knockout rats.
Juan M Dominguez - One of the best experts on this subject based on the ideXlab platform.
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influences of dopamine and glutamate in the medial preoptic area on Male Sexual Behavior
Pharmacology Biochemistry and Behavior, 2014Co-Authors: Ryan G Will, Elaine M. Hull, Juan M DominguezAbstract:Abstract Several brain nuclei interact to orchestrate the appetitive and consummatory aspects of Male Sexual Behavior. Of these structures, the medial preoptic area (mPOA) of the hypothalamus is of particular interest, as it receives input from all sensory modalities, and damage to this region disrupts copulation in a wide variety of taxa. Furthermore, the mPOA is both responsive to gonadal hormones and involved in endocrine regulation. Neurochemical studies have demonstrated that both dopamine and glutamate levels rise in the mPOA in response to Sexual activity, while antagonism of these neurotransmitters impairs Male Sexual response. Here we review how dopamine and glutamate act in the mPOA to modulate Male Sexual Behavior.
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A Comparative Approach to the Study of Dopamine and Male Sexual Behavior: What Can Japanese Quail Teach Us? A Reply to Pfaus (2010)
Behavioral Neuroscience, 2010Co-Authors: Hayley K. Kleitz-nelson, Juan M Dominguez, Gregory F. BallAbstract:One of the most robust findings about dopamine (DA) is that the stimulation of dopaminergic systems promotes the activation of Male Sexual Behavior. The commentary by Pfaus (2010) included a thorough review of studies of DA and Male Sexual Behavior. We agree with him that the release of DA in the preoptic region in Male quail in response to feMales and in association with the exhibition of Male Sexual Behavior appears to be highly conserved and that it seems to have evolved very early in the evolutionary history of the vertebrate brain. However, additional data have been collected indicating that there may be significant species differences in the dopaminergic regulation of Male Behavior in quail compared with rats. In this response, we take the opportunity to make a few broader points about DA and Male Sexual Behavior in light of other studies that have been conducted in birds and introduce some interesting taxonomic variation that is still not well understood.
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a role for hypocretin orexin in Male Sexual Behavior
The Journal of Neuroscience, 2007Co-Authors: John W Muschamp, Juan M Dominguez, Satoru M Sato, Rohyu Shen, Elaine M. HullAbstract:The role of hypocretin (orexin; hcrt/orx) neurons in regulation of arousal is well established. Recently, hcrt/orx has been implicated in food reward and drug-seeking Behavior. We report here that in Male rats, Fos immunoreactivity (ir) in hcrt/orx neurons increases markedly during copulation, whereas castration produces decreases in hcrt/orx neuron cell counts and protein levels in a time course consistent with postcastration impairments in copulatory Behavior. This effect was reversed by estradiol replacement. Immunolabeling for androgen (AR) and estrogen (ERα) receptors revealed no colocalization of hcrt/orx with AR and few hcrt/orx neurons expressing ERα, suggesting that hormonal regulation of hcrt/orx expression is via afferents from neurons containing those receptors. We also demonstrate that systemic administration of the orexin-1 receptor antagonist SB 334867 [N-(2-methyl-6-benzoxazolyl)-N″-1,5-naphthyridin-4-yl urea] impairs copulatory Behavior. One locus for the proSexual effects of hcrt/orx may be the ventral tegmental area (VTA). We show here that hcrt-1/orx-A produces dose-dependent increases in firing rate and population activity of VTA dopamine (DA) neurons in vivo. Activation of hcrt/orx during copulation, and in turn, excitation of VTA DA neurons by hcrt/orx, may contribute to the robust increases in nucleus accumbens DA previously observed during Male Sexual Behavior. Subsequent triple immunolabeling in anterior VTA showed that Fos-ir in tyrosine hydroxylase-positive neurons apposed to hcrt/orx fibers increases during copulation. Together, these data support the view that hcrt/orx peptides may act in a steroid-sensitive manner to facilitate the energized pursuit of natural rewards like sex via activation of the mesolimbic DA system.
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preoptic glutamate facilitates Male Sexual Behavior
The Journal of Neuroscience, 2006Co-Authors: Juan M Dominguez, Elaine M. HullAbstract:The medial preoptic area (MPOA) is a critical regulatory site for the control of Male Sexual Behavior. We first measured glutamate in 2 min microdialysate samples from the MPOA before, during, and after copulation by Male rats. There was a slight [∼140% of baseline (BL)] rise in extracellular glutamate when the feMale was presented, a significant increase (∼170% of BL) during periods of mounting and intromitting, and a very large increase in samples collected during ejaculation (∼300% of BL). A precipitous fall in levels occurred in the first postejaculatory sample; the magnitude of this fall was highly correlated with the length of the postejaculatory interval of quiescence. In experiment 2, we reverse-dialyzed a mixture of glutamate uptake inhibitors into the MPOA before and during mating; control animals received artificial CSF. The mixture increased extracellular glutamate (∼280% of BL), increased the number of ejaculations in the 40 min test, decreased ejaculation latency, and decreased the postejaculatory latency to resume copulation. These data, together with other findings that glutamate in the MPOA can elicit genital reflexes in anesthetized rats and that glutamate receptor antagonists in the MPOA impair copulation, strongly suggest that MPOA glutamate is a major facilitator of copulation and that the postejaculatory fall in glutamate regulates the postejaculatory interval.
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dopamine the medial preoptic area and Male Sexual Behavior
Physiology & Behavior, 2005Co-Authors: Juan M Dominguez, Elaine M. HullAbstract:The medial preoptic area (MPOA), at the rostral end of the hypothalamus, is important for the regulation of Male Sexual Behavior. Results showing that Male Sexual Behavior is impaired following MPOA lesions and enhanced with MPOA stimulation support this conclusion. The neurotransmitter dopamine (DA) facilitates Male Sexual Behavior in all studied species, including rodents and humans. Here, we review data indicating that the MPOA is one site where DA may act to regulate Male Sexual Behavior. DA agonists microinjected into the MPOA facilitate Sexual Behavior, whereas DA antagonists impair copulation, genital reflexes, and Sexual motivation. Moreover, microdialysis experiments showed increased release of DA in the MPOA as a result of precopulatory exposure to an estrous feMale and during copulation. DA may remove tonic inhibition in the MPOA, thereby enhancing sensorimotor integration, and also coordinate autonomic influences on genital reflexes. In addition to sensory stimulation, other factors influence the release of DA in the MPOA, including testosterone, nitric oxide, and glutamate. Here we summarize and interpret these data.