The role of adrenoceptors in the central nervous system in male and female rat sexual behavior

Abstract

Three different phases can be distinguished in rats' sexual cycle, the introductory (precopulatory), the copulatory and the executive (ejaculatory) phases. In this review, a new analysis of existing pharmacological data is made, both in male and female rats, in which the different aspects of sexual behavior are taken into account. An effort is made to distinguish pharmacological effects on sexual behavior from a possible physiological role of noradrenaline. In addition, new data on the role of α2-adrenoceptors on female sexual behavior is presented. The new analysis suggests that noradrenaline has a stimulatory role on the executive phase of male sexual behavior, while the introductory and copulatory phases remain unaffected. Adrenoceptors play a role in the regulation of sexual behavior in the medial preoptic area and the lateral septum. In female rats, noradrenaline also does not play a vital role in the introductory phase. Only the lordosis behavior of the copulatory phase is sometimes affected by adrenergic agents, but only under a certain hormonal condition. The medial preoptic area, the ventromedial nucleus, the arcuate ventromedial nucleus and median eminence are involved in the regulation of female sexual behavior. The new data suggest that α2-adrenoceptors play no major role on any indices of female sexual behavior.

Prenatal Hypoxia Ischemia Increases Male Rat Sexual Behavior

“…The current study demonstrated that a single event of maternal hypoxia has a direct influence on sexual behavior. Prenatal hypoxia ischemia facilitation of sexual behavior in male rats was demonstrated by: (i) a significant reduction in mounting (tests 1 to 4, Figure 1A) and intromission latencies (tests 1 to 3, Figure 1B), which suggests enhanced arousal or motivational mechanisms [26][27][28][29][30][31][32][33][34][35]; (ii) a reduction in mount frequency (test 1, Figure 1D), an increase in copulatory efficiency (tests 3 and 4, Figure 1F) and a decrease in ejaculation latency (tests 3 and 4, Figure 1G), which suggests a decrease in the ejaculatory threshold [26,[28][29][30][31][32][33][34][35]; (iii) HI rats showed homosexual mounting behavior in conditions in which this behavior did not occur in control rats; and (iv) compared with controls, significantly more rats in the HI group not only mounted a receptive female but also fought trying to mount an unreceptive female. Hermans et al [18], employing a different model of prenatal hypoxia, reported that male rats that were prenatally exposed to hypoxia had significantly delayed initiation latencies of masculine sexual behavior and a decreased number of ejaculations.…”

“…Central regulation of sexual behavior is complex and involves various neurotransmitter systems and/or neuropeptides [26,28,29,[33][34][35]37,38,[40][41][42][43][44][45]. It has been established that central dopamine is a key neurotransmitter in the control of sexual function [26,28,29,37,38,[40][41][42].…”

Sexual dimorphisms in swimming behavior, cerebral metabolic activity and adrenoceptors in adult zebrafish (Danio rerio)

“…The noradrenergic functions are mediated via specific G-proteincoupled membrane receptors, the adrenoceptors [27], classified to α 1 , α 2 , β 1 , β 2 , β 3 -adrenoceptors, (ARs) subtypes in mammals [26,28], with both post-or pre-synaptic localization. Adrenoceptors have been associated to the released sex steroid hormones levels and in turn to a variety of essential sex-specific functions, like reproductive behavior and courtship in breeding season ewes [29] and in rat male female sexual behavior [30]. Indeed, adrenoceptors are known to display sex dimorphic pattern in brain areas of avian [31,32] and mammalian [33] species.…”

Female Reproductive Behavior

“…Systematic administration of an α2adrenoceptor agonist, for instance, does not have an effect on lordosis in female rats (Davis and Kohl, 1977). Similar lack of results were found with the administration of non-selective and selective α2-adrenoceptor antagonists: no effects were found on sexual incentive motivation, paracopulatory behavior and lordosis (Snoeren, 2015, Gonzalez et al, 1996, Davis and Kohl, 1977, Ventura-Aquino and Fernandez-Guasti, 2013. This suggests that, systemically, α2adrenoceptors are not involved in the regulation of female sexual behavior.…”

“…Adrenoceptors are located in the brain, spinal cord and periphery (Frankhuyzen andMulder, 1982, Nasseri andMinneman, 1987), and are localized both post-and presynaptically, as inhibitory receptors on non-adrenergic neurons (heteroceptors) and on the terminals and dendrites of the noradrenergic neurons themselves (autoreceptors) (Frankhuyzen andMulder, 1982, Nasseri andMinneman, 1987). Again, the different adrenoceptors seem to play diverse roles in female reproductive behavior (reviewed in (Snoeren, 2015).…”