Sexual behavior decreases pain sensitivity and stimulates endogenous opioids in male rats

doi:10.1016/0014-2999(81)90161-8

European Journal of Pharmacology

Volume 70, Issue 3, 26 March 1981, Pages 279-285

https://doi.org/10.1016/0014-2999(81)90161-8 Get rights and content

Abstract

In male rats copulation has antinociceptive effects as measured either by shock-induced vocalizations or hindlimb withdrawal to pinch. Prolonged mating reduces the content of endogenous opioids in midbrain but not in hypothamlamus or caudate nucleus. Blockage of opiate receptors with the narcotic antagonist naloxone (4 mg/kg) significantly extends the postejaculatory interval. The results indicate that mating is a biological stimulus for the release of endogenous opioids, possibly to (a) prevent intense sexual stimulation from becoming aversive, and (b) increase its reward value.

References (35)

R. Eibergen et al.
Acceleration and pacing of copulatory performance of male rats by repeated, aversive brain stimulation
Physiol. Behav.
(1975)
B.R. Komisaruk et al.
Suppression of a spinal and cranial nerve reflex by vaginal or rectal probing in rats
Brain Res.
(1971)
B.J. Meyerson et al.
β-endorphin and male sexula behavior
European J. Phamacol.
(1977)
B.M. Myers et al.
Facilitation by opiate antagonists of sexual performance in the male rat
Pharmacol. Biochem. Behav.
(1979)
H. Szechtman et al.
Plasma corticosterone levels during sexual behavior in male rats
Horm. Behav.
(1974)
R.J. Barfield et al.
Sexual behavior: stimulation by painful electric shock to skin in male rats
Sciences
(1968)
R.J. Barfield et al.
Sexual behavior: extreme reduction of the post-ejaculatory refractory period by posterior hypothalamic lesions in male rats
Science
(1975)
J.D. Belluzi et al.
Analgesia induced in vivo by central administration of enkephalin in rat
Nature
(1976)
J.D. Belluzi et al.
Enkephalin may mediate euphoria and drive-reduction reward
Nature
(1977)
T.K. Clark et al.
Sexual inhibition is reduced by rostral midbrain lesions in the male rat
Science
(1975)

G.L. Gessa et al.

Induction of copulatory behavior in sexually inactive rats by naloxone

Science

(1979)

R. Guillemin et al.

β-endorphin and adrenocorticotropin are secreted concomitantly by the pituitary gland

Science

(1977)

D.F. Hardy et al.

Effects of coital stimulation upon behavior of the female rat

J. Comp. Physiol. Psychol.

(1972)

L. Heimer et al.

Drastic changes in the mating behavior of male rats following lesions in the junction of diecephalon and mesencephalon

Experientia

(1964)

J. Hetta

Effects of morphine and naltrexone on sexual behavior of the male rat

Acta Pharmacol. Toxicol.

(1977)

A.C. Kinsey et al.

Sexual Behavior in the Human Female

(1973)

B.R. Komusaruk et al.

Antinociceptive effects of vaginal stimulation in rats: Neuphysiological and behavioral studies

Brain, Res.

(1977)

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Sexual and aggressive behaviors are vital for species survival and individual reproductive success. Although many limbic regions have been found relevant to these behaviors, how social cues are represented across regions and how the network activity generates each behavior remains elusive. To answer these questions, we utilize multi-fiber photometry (MFP) to simultaneously record Ca²⁺ signals of estrogen receptor alpha (Esr1)-expressing cells from 13 limbic regions in male mice during mating and fighting. We find that conspecific sensory information and social action signals are widely distributed in the limbic system and can be decoded from the network activity. Cross-region correlation analysis reveals striking increases in the network functional connectivity during the social action initiation phase, whereas late copulation is accompanied by a “dissociated” network state. Based on the response patterns, we propose a mating-biased network (MBN) and an aggression-biased network (ABN) for mediating male sexual and aggressive behaviors, respectively.
Sexual experience increases oxytocin, but not vasopressin, receptor densities in the medial preoptic area, ventromedial hypothalamus, and central amygdala of male rats
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Oxytocin (OT) and vasopressin (VP) are considered to be principal neurochemical substrates of bonding in monogamous species. We have reported previously that conditioning of a sexual partner preference in male rats resulted in conditioned activation of OT and VP neurons in hypothalamic paraventricular and supraoptc nuclei. Here we asked whether such conditioning would also alter OT or VP receptor densities. Sexually naïve male rats were assigned to one of three groups (n = 15/group). The Paired group received 9 copulatory training trials with sexually receptive females scented with a neutral almond odor. The Unpaired group received 9 copulatory training trials with unscented sexually receptive females. The Naïve group were not given sexual experience. Paired and Unpaired males were given a final test in an open field with two receptive females, one scented and the other unscented, to assess the development of conditioned ejaculatory preference (CEP), which was expressed significantly in the Paired group. Brains from rats in the three groups were then assessed for OT receptor (OTR) or VP1a receptor (VPR) densities within cortical, limbic and hypothalamic structures using autoradiography with selective ¹²⁵I-labeled receptor ligands. Sexual experience alone increased OTR significantly in the medial preoptic area (mPOA), ventromedial hypothalamus (VMH), and central nucleus of the amygdala (CeA) in both Paired- and Unpaired-trained males compared to sexually Naïve males. No differences were found for experience on VPR densities in any region. These data add to a growing body of evidence that sexual experience alters brain function and processing of sex-related cues, and suggest that enhanced activation of OTRs in the mPOA, VMH, and CeA by conditioned OT release in those regions may underlie CEP in the male rat.
Mating-induced analgesia is dependent of copulatory male pattern in high- and low- yawning male rats
2022, Physiology and Behavior
Citation Excerpt :
Male sexual behavior differs among mammalian species and can induce different endocrine, behavioral, and adaptive changes including alterations in pain sensation [9, 14, 20, 44].
Mating behavior in rodents can modulate pain sensations in both sexes. In males, the execution of mounts, intromissions, and ejaculations induced a progressive increase in their vocalization thresholds induced by tail shocks and other types of noxious stimuli.
We selectively inbred two sublines from Sprague-Dawley (SD) rats that differed in their spontaneous yawning frequency. The high-yawning (HY) subline had a mean of 20 yawns/h and a different pattern of sexual behavior characterized by longer interintromission intervals and more sexual bouts that delayed ejaculation. The low-yawning (LY) subline and SD rats yawned as a mean 2 and 1 yawns/h, respectively.
So, we determine mating-induced analgesia in HY, LY, and SD male rats by measuring vocalization thresholds in response to noxious electric tail shocks. Our results showed that the magnitude of mating-induced analgesia was lower in HY and LY rats with respect to SD rats. When the rats performed different components of male sexual pattern, both sublines exhibited a significantly lower increase in their vocalization thresholds with respect to SD rats—being sublines less responsive regarding mating-induced analgesia. Pain modulation mechanisms depend on responses to stress, so the low levels of analgesia obtained in the yawning sublines may be due either to differences in their response to stress in other paradigms, or to atypical performance of male sexual behavior during mating, an event which as a stressful event in rats.
Therefore, the yawning sublines are a suitable model for analyzing how a different temporal pattern in the display of male sexual behavior affects analgesia mechanisms. Our results concur with Wistar rats with different endophenotypes that could apply to humans as well.
Beyond Pain: A Study on the Variance of Pain Thresholds Within BDSM Interactions in Dominants and Submissives
2021, Journal of Sexual Medicine
BDSM is an acronym describing bondage and discipline, dominance and submission, and sadism and masochism. Afflicting or receiving pain is usually an important part of the BDSM interaction.
This research will focus on better understanding the aspect of pain within a BDSM interaction.
Submissive and dominant counterparts of 35 couples were recruited to participate in a BDSM interaction, of which 34 dominants and 33 submissives were included in the analyses. A non-BDSM interested control group (n = 27) was included to control for social interaction, of which 24 were included in the analyses.
This research investigates the differences in (i) baseline pain thresholds, (ii) the impact of a BDSM interaction on those thresholds, and (iii) threshold moderating factors like pain cognition between submissive and dominant BDSM participants and control individuals.
BDSM practitioners have a higher pain threshold overall and a BSDM interaction will result in a temporary elevation of pain thresholds for submissives. Additionally, pain thresholds in dominants will be dependent upon their fear of pain and tendency to catastrophize pain and submissives will experience less fear of pain than the control group.
By further enhancing our understanding of the mechanisms behind a BDSM interaction in this way, we aspire to relieve the stigma these practitioners still endure.
This is one of the first studies of its kind with a large sample size compared to similar research, which makes it a significant contribution to the field. It must be mentioned that there is a possible selection bias because recruitment was only done through the Flemish BDSM community and specifically those who visit clubs. Additionally, pain threshold remains a subjective measurement, which must be taken into account.
This study helps shed further light on the biological processes behind a BDSM interaction through pain threshold measurements.
Wuyts E, De Neef N, Coppens V, et al. Beyond Pain: A Study on the Variance of Pain Thresholds Within BDSM Interactions in Dominants and Submissives. J Sex Med 2021;18:556–564.
A mu-opioid feedback model of human social behavior
2021, Neuroscience and Biobehavioral Reviews
Since the discovery of pain relieving and rewarding properties of opiates such as morphine or heroin, the human mu-opioid system has been a target for medical research on pain processing and addiction. Indeed, pain and pleasure act mutually inhibitory on each other and the mu-opioid system has been suggested as an underlying common neurobiological mechanism. Recently, research interest extended the role of the endogenous mu-opioid system beyond the hedonic value of pain and pleasure towards human social-emotional behavior. Here we propose a mu-opioid feedback model of social behavior. This model is based upon recent findings of opioid modulation of human social learning, bonding and empathy in relation to affiliative and protective tendencies. Fundamental to the model is that the mu-opioid system reinforces socially affiliative or protective behavior in response to positive and negative social experiences with long-term consequences for social behavior and health. The functional implications for stress, anxiety, depression and attachment behaviors are discussed.
Endocannabinoids mediate long-lasting behavioural and physiological changes in male rats induced by the repeated activation of the mesolimbic system by copulation to satiety
2020, Behavioural Brain Research
Sexually satiated male rats exhibit long-lasting physiological changes, suggestive of brain plasticity, the most conspicuous of which are a sexual behaviour inhibition and a generalised drug hypersensitivity. Copulation activates the mesolimbic circuit increasing dopamine (DA) release in the nucleus accumbens (NAcc) and, enhanced midbrain DA neuron activity promotes endocannabinoid (eCB) release in the ventral tegmental area (VTA). The objective of this work was to explore the possible participation of DA and/or eCB transmission in the induction of these two long-lasting phenomena. To this aim we analysed the effect of blocking DA or CB1 receptors during the process of copulation to exhaustion, on the expression 24 h later, of the sexual inhibitory state and the hypersensitivity to two different drugs: 8-OH-DPAT, a 5-HT_1A receptor agonist, and yohimbine, an α₂-adrenoceptor antagonist. Blockade of DA receptors failed to prevent these phenomena, while blockade of CB1 receptors interfered with the appearance of the sexual inhibition and the hypersensitivity to both drugs in the sexually satiated animals. Specific blockade of CB1 receptors in the VTA during copulation to satiety mimicked these results, suggesting that both eCB-mediated effects were exerted in this brain region. It is concluded that eCBs play a role in the induction of behavioural and physiological changes, triggered by copulation to satiety, by acting at the VTA, while increased NAcc DA levels appear not to contribute to the changes induced by intense copulation. Results pose sexual satiety as a useful model for the study of brain plasticity phenomena induced by natural rewards.

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Regular paperSexual behavior decreases pain sensitivity and stimulates endogenous opioids in male rats

Abstract

Physiol. Behav.

Brain Res.

European J. Phamacol.

Pharmacol. Biochem. Behav.

Horm. Behav.

Sexual behavior: stimulation by painful electric shock to skin in male rats

Sciences

Sexual behavior: extreme reduction of the post-ejaculatory refractory period by posterior hypothalamic lesions in male rats

Science

Analgesia induced in vivo by central administration of enkephalin in rat

Nature

Enkephalin may mediate euphoria and drive-reduction reward

Nature

Sexual inhibition is reduced by rostral midbrain lesions in the male rat

Science

Induction of copulatory behavior in sexually inactive rats by naloxone

Science

β-endorphin and adrenocorticotropin are secreted concomitantly by the pituitary gland

Science

Effects of coital stimulation upon behavior of the female rat

J. Comp. Physiol. Psychol.

Drastic changes in the mating behavior of male rats following lesions in the junction of diecephalon and mesencephalon

Experientia

Effects of morphine and naltrexone on sexual behavior of the male rat

Acta Pharmacol. Toxicol.

Sexual Behavior in the Human Female

Antinociceptive effects of vaginal stimulation in rats: Neuphysiological and behavioral studies

Brain, Res.

Regular paper
Sexual behavior decreases pain sensitivity and stimulates endogenous opioids in male rats