Copulatory Tests Research Articles

Male Roman high and low avoidance rats show different patterns of copulatory behaviour: Comparison with Sprague Dawley rats

Roman high- (RHA) and low-avoidance (RLA) rats, selectively bred for, respectively, rapid vs. extremely poor acquisition of avoidant behaviour in the shuttle-box, display different coping strategies when exposed to aversive environmental conditions: RLA rats are reactive copers and show hyperemotional behaviour characterized by hypomotility and freezing, while RHA rats show a proactive coping behaviour aimed at gaining control over the stressor. RHA rats also display a robust sensation/novelty seeking profile, high baseline levels of impulsivity, and marked preference for, and intake of, natural and drug rewards. This study shows that the Roman lines also differ in sexual behaviour, a main source of natural reward. Thus, male RHA rats engaged in copulatory activity with a receptive female showing more mounts, intromissions and ejaculations in the first copulation test as compared with their RLA counterparts and Sprague Dawley rats used as an external reference strain. Such differences decreased only partially in subsequent copulation tests, with RHA rats always showing higher levels of sexual motivation and performance than RLA rats. Accordingly, analysis of copulatory parameters of five copulation tests performed at 3-day intervals confirmed that the Roman lines display different patterns of copulatory activity that persist after stabilization of copulatory behaviour by sexual experience. Finally, the weight of the testes, epididymides and seminal vesicles increased to a similar extent in both Roman lines after sexual activity. These results are discussed in terms of the relative contribution of differences in brain neurotransmission (mainly dopamine) and neuroendocrine function to the different patterns of copulatory behaviour of the Roman lines.

Somatosensory conditioning of sexual arousal and copulatory behavior in the male rat: A model of fetish development

Previous studies have established that neutral olfactory cues associated with sexual reward or inhibition become conditioned stimuli that direct male or female rats toward or away from potential sex partners bearing the cue. Here we examined the ability of a somatosensory cue to exert stimulus control over sexual arousal and copulation in male rats. In the first experiment, two groups of sexually naïve male rats had their first copulatory experiences with receptive females in bilevel chambers with or without a rodent jacket. On a final copulatory test, half of the rats in each group were tested with the jacket on or off. Rats trained and tested without the jacket copulated normally, as did rats trained and tested with the jacket on, and rats trained without the jacket but tested with the jacket on. However, significantly fewer rats trained with the jacket on but tested with the jacket off copulated to ejaculation, and those that did made significantly fewer anticipatory level changes and had fewer significantly longer mount, intromission, and ejaculatory latencies, and fewer ejaculations. In the second experiment, one group of sexually naïve males was given differential conditioning trials in bilevel chambers to associate the jacket on with sexual reward (copulation to ejaculation with a sexually receptive female) and the jacket off with sexual inhibition (thwarted copulatory attempts with a sexually nonreceptive female). A second group had the opposite order of association. A final test with receptive females was made for all males with the jacket on. Males trained to associate the jacket with excitation displayed normal copulation whereas males trained to associate the jacket with inhibition displayed significantly fewer anticipatory level changes and ejaculations, and had significantly longer ejaculation latencies. Thus, somatosensory cues can signal sexual excitation or inhibition in male rats depending on the conditioning history.

C‐fos down‐regulation inhibits testosterone‐dependent male sexual behavior and the associated learning

Environmental stimulation results in an increased expression of transcription factors called immediate early genes (IEGs) in specific neuronal populations. In male Japanese quail, copulation with a female increases the expression of the IEGs zenk and c-fos in the medial pre-optic nucleus (POM), a key nucleus controlling male sexual behavior. The functional significance of this increased IEG expression that follows performance of copulatory behavior is unknown. We addressed this question by repeatedly quantifying the performance of appetitive (learned social proximity response) and consummatory (actual copulation) sexual behavior in castrated, testosterone-treated males that received daily intra-cerebroventricular injection of an antisense oligodeoxynucleotide targeting c-fos or control vehicle. Daily antisense injections significantly inhibited the expression of copulatory behavior as well as the acquisition of the learned social proximity response. A strong reduction of the proximity response was still observed in antisense-treated birds that copulated with a female, ruling out the indirect effect of the absence of interactions with females on the learning process. After a 2-day interruption of behavioral testing but not of antisense injections, birds were submitted to a final copulatory test that confirmed the behavioral inhibition in antisense-injected birds. Brains were collected at 90 min after the behavioral testing for quantification of c-fos-immunoreactive cells. A significant reduction of the number of c-fos-positive cells in the POM but not in other brain regions was observed following antisense injection. Taken together, the data suggest that c-fos expression in the POM modulates copulatory behavior and sexual learning in male quail.

A small cohort of FRUM and Engrailed-expressing neurons mediate successful copulation in Drosophila melanogaster

BackgroundIn Drosophila, male flies require the expression of the male-specific Fruitless protein (FRUM) within the developing pupal and adult nervous system in order to produce male courtship and copulation behaviors. Recent evidence has shown that specific subsets of FRUM neurons are necessary for particular steps of courtship and copulation. In these neurons, FRUM function has been shown to be important for determining sex-specific neuronal characteristics, such as neurotransmitter profile and morphology.ResultsWe identified a small cohort of FRUM interneurons in the brain and ventral nerve cord by their co-expression with the transcription factor Engrailed (En). We used an En-GAL4 driver to express a fruM RNAi construct in order to selectively deplete FRUM in these En/FRUM co-expressing neurons. In courtship and copulation tests, these males performed male courtship at wild-type levels but were frequently sterile. Sterility was a behavioral phenotype as these En-fruMRNAi males were less able to convert a copulation attempt into a stable copulation, or did not maintain copulation for long enough to transfer sperm and/or seminal fluid.ConclusionsWe have identified a population of interneurons necessary for successful copulation in Drosophila. These data confirm a model in which subsets of FRUM neurons participate in independent neuronal circuits necessary for individual steps of male behavior. In addition, we have determined that these neurons in wild-type males have homologues in females and fru mutants, with similar placement, projection patterns, and neurochemical profiles.

1031 ASSOCIATION BETWEEN SERUM LEPTIN LEVEL AND SEXUAL BEHAVIOR IN PSYCHOLOGICALLY STRESSED MALE RATS

You have accessJournal of UrologySexual Function/Dysfunction/Andrology: Basic Research (II)1 Apr 20131031 ASSOCIATION BETWEEN SERUM LEPTIN LEVEL AND SEXUAL BEHAVIOR IN PSYCHOLOGICALLY STRESSED MALE RATS Yoshiji Miwa, Masaya Seki, and Osamu Yokoyama Yoshiji MiwaYoshiji Miwa Fukui, Japan More articles by this author , Masaya SekiMasaya Seki Fukui, Japan More articles by this author , and Osamu YokoyamaOsamu Yokoyama Fukui, Japan More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.616AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Chronic psychological stress has been linked to a number of negative health consequences, including effects on the cardiovascular, endocrine, immune, and reproductive systems. Recently it has been reported that despite a decrease in both body weight gain and adipose tissue weight, chronic restraint stress evoked low-grade inflammation in murine adipose tissue, similar to that seen in metabolic syndrome. This inflammatory change involved the induction of proinflammatory adipokines and a decrease in adiponectin. Leptin, a protein hormone produced by adipose tissue, plays a role in regulating energy intake and expenditure, and facilitating sexual behavior. The aim of this study was to investigate the association between serum leptin level and sexual behavior in psychologically stressed male rats. METHODS Adult male Wistar-Kyoto rats were divided into 2 groups: a control group (n=16) and a psychological stress loading group (PS, n=16). The PS rats were exposed to psychological stress for 2 hours per day for 10 consecutive days, and the control rats were exposed to clean and empty cages (sham stress) for 2 hours per day for 10 consecutive days. Psychological stress was induced by the communication box. After the last stress loading, their copulatory behavior with receptive females was tested. During the test, the mount latency, intromission latency, and ejaculation latency were recorded. Prolonged latencies show sexual behavior to be reduced. Immediately after the copulation test, blood samples were collected and serum leptin, corticosterone, total testosterone, free testosterone, LH, FSH and estradiol levels were determined. RESULTS The PS rats had significantly longer latencies, lower leptin level, and higher corticosterone level than did the control rats (p<0.01, 0.001 and 0.019, respectively). There was a significant negative correlation between latencies and serum leptin level. CONCLUSIONS These results show that psychologically suppressed masculine sexual behavior could be associated with decreased serum leptin level caused by stress-induced dysfunctional adipose tissue. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e422 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Yoshiji Miwa Fukui, Japan More articles by this author Masaya Seki Fukui, Japan More articles by this author Osamu Yokoyama Fukui, Japan More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Effect of Dapoxetine on Ejaculatory Performance and Related Brain Neuronal Activity in Rapid Ejaculator Rats

A brain network specifically activated when ejaculation occurs has been described in rats. Increasing serotonin (5-hydroxytryptamine [5-HT]) tone impairs ejaculation and chronic 5-HT selective serotonin reuptake inhibitors (SSRIs) are known to inhibit ejaculation. However, efficacy of acute treatment with SSRI varies from one compound to another. The SSRI dapoxetine has been reported to delay ejaculation when given on demand to men with premature ejaculation (PE), although the mechanism of action is unclear. Effects of acute SSRIs on activity of the brain ejaculation circuit in relation with ejaculation have never been examined. To test the effects of acute administration of the short half-life SSRI dapoxetine on ejaculatory performance and activity in brain ejaculation circuit in rapid ejaculator rats taken as PE model. Standard copulatory test was used to attribute one sexual category (sluggish, middle, or rapid) to male rats on the basis of their ejaculatory performance. Parameters of sexual, including ejaculatory, behavior, and Fos level of expression in discrete brain areas were assessed in the three sexual categories and in rapid category following acute oral treatment with dapoxetine. Ejaculation frequency (EF) and latency (EL) were measured as primary end points of ejaculatory behavior. Density of Fos-immunopositive cells in specific brain areas of brain stem, hypothalamus, and thalamus was determined as marker of neuronal activity. EL and Fos level of expression in hypothalamic and thalamic structures were found related. Dapoxetine acute oral administration (300 mg/kg) to rapid ejaculator rats resulted in (i) diminution of ejaculatory performance (lengthened EL and decreased EF); and (ii) modulation of Fos level of expression in hypothalamic and thalamic nuclei of the brain ejaculatory circuit. Acute treatment with dapoxetine, which reduced ejaculatory performance in rapid ejaculator rats, was also accompanied with changes in neuronal activity in components of the brain ejaculatory network.

Effect of dexmedetomidine on ejaculatory behavior and sexual motivation in intact male rats

Premature ejaculation is the most common sexual disorder in young men. Consequently, there is an intense search for efficient and safe pharmacological treatments. Insofar, almost no effective treatment with acute effects is available. In this study, we evaluated the effects of the noradrenergic α2 receptor agonist dexmedetomidine on sexual incentive motivation and copulatory behavior in male rats. Sexual incentive motivation was tested in a large rectangular arena connected to two small incentive stimulus cages containing either a male or sexually receptive female rat. There was no sexual interaction possible between the experimental subjects and the incentives during this test. Approach to the incentives constituted the measure of sexual incentive motivation. After the sexual incentive motivation test, the subjects were tested for copulatory behavior in a regular copulation test for 30min. Doses of 0.1 and 1μg/kg of dexmedetomidine (i.p.) had no effect on any of the indices of locomotor activity or on parameters of sexual incentive motivation. With regard to copulatory behavior, it was found that the dose of 1μg/kg prolonged the latency to the first ejaculation, while the latency to second ejaculation showed a tendency to increase. The absence of an effect on indices of sexual incentive motivation or general activity showed that the actions of dexmedetomidine in this study were limited to ejaculatory mechanisms. Insofar as the ejaculation latency in the male rat is predictive of prolonged ejaculation latency in men, it can be proposed that dexmedetomidine is of potential utility for the treatment of premature ejaculation.

Dopamine D1 receptors and phosphorylation of dopamine- and cyclic AMP-regulated phosphoprotein-32 in the medial preoptic area are involved in experience-induced enhancement of male sexual behavior in rats.

The medial preoptic area (MPOA) is an integral site for male sexual behavior. Dopamine is released in the MPOA before and during copulation and facilitates male rat sexual behavior. Repeated sexual experience and noncopulatory exposures to an estrous female facilitate subsequent copulation. However, the neurobiological mechanisms that mediate such enhancement remain unclear. Here, we examined the role of dopamine D₁ receptors in the MPOA in experience-induced enhancement of male sexual behavior in rats. In experiment 1, microinjections of the D₁ antagonist SCH-23390 into the MPOA before each of seven daily 30-min noncopulatory exposures to a receptive female impaired copulation on a drug-free test on Day 8, compared to vehicle-treated female-exposed animals. Copulatory performance in drug-treated animals was similar to that of vehicle-treated males that had not been preexposed to females. This effect was site specific. There were no group differences in locomotor activity in an open field on the copulation test day. In experiment 2, a separate cohort of animals was used to examine phosphorylation of dopamine- and cAMP-regulated phosphoprotein (DARPP-32) in the MPOA of animals with acute and/or chronic sexual experience. DARPP-32 is a downstream marker of D₁ receptor signaling and substrate of cAMP-dependent protein kinase (PKA). Western immunoblot analysis revealed that p-DARPP-32 expression was greatest in the MPOA of males that received both acute and chronic sexual experience, compared to all other mated conditions and naïve controls. These data suggest that D₁ receptors in the MPOA contribute to experience-induced enhancement of male sexual behavior, perhaps through a PKA regulated mechanism.

Analysis of sexual behaviour in male rabbits across successive tests leading to sexual exhaustion

Various parameters of sexual behaviour were studied in ten male rabbits daily tested with sexually receptive females (ovariectomized, given estradiol benzoate s.c. 5 µg/day). The aim of this study was to analyse rabbit sexual behaviour during successive tests leading to sexual exhaustion. We allowed copulation ad libitum and determined if sexual satiety was reached within a day and sexual exhaustion across several days. The pair was allowed to copulate freely until the male failed to show sexual interest in that female for 30 minutes. The female was then removed and replaced by another; this procedure was repeated using as many does as needed, until the male showed no interest in any female for 2 hours. Scent-marking (chinning) was also recorded, before and after the copulation test. This whole procedure was repeated daily until the male showed no sexual behaviour at all on a given day. Within a test, copulation ad libitum led to a gradual increase in the time interval between successive mounts and ejaculations, regardless of the day of testing. Such increments predicted that the buck was reaching sexual satiety. The “miss” rate (i.e., the proportion of mounts that did not culminate in ejaculation) significantly increased from a median of 25 on the first day to 55 on the last day of testing. The mean time to reach copulatory inactivity decreased from 4 hrs on the first day to 1 hr on the last day. The total number of ejaculations within a test decreased from an average of 22 to 6 (first vs last day, respectively) and the number of chin marks was reduced by 69% compared with pre-mating values, regardless of the day of testing. All bucks eventually stopped copulating after a variable number of days (range=2-15 days). We concluded that, following copulation ad libitum with several females, male rabbits reach sexual satiety (i.e., they are unable to continue copulating on the same day) and, after several days, they also attain sexual exhaustion, a state in which copulation is totally arrested for at least 24 hours. Some behavioural parameters can be used as reliable predictors that a buck is approaching sexual satiety and sexual exhaustion.

The Dose‐Dependent Effect of Chronic Administration of Haloperidol, Risperidone, and Quetiapine on Sexual Behavior in the Male Rat

Antipsychotic drug-induced sexual dysfunction is a common and problematic side effect, which may diminish quality of life and lead to treatment noncompliance. Up to date, there is still a scarcity of basic research regarding the chronic effects of most antipsychotic agents on sexual behavior. The present study investigated the effect of a range of doses of three antipsychotic drugs (haloperidol, risperidone, and quetiapine) on male rat sexual competence following chronic administration. Twelve groups of Sprague-Dawley rats (n = 7 each) received by gavage haloperidol (0.25, 0.5, or 1 mg/kg), risperidone (0.125, 0.25, or 0.5 mg/kg), quetiapine (10, 20, and 40 mg/kg) or vehicle (distilled water) in the corresponding control groups, respectively, once daily for 21 days. Sexual function was evaluated by the copulatory behavior test 10 hours after the last dose. The male rat behavioral parameters of copulatory test. Sexual function was widely and significantly suppressed by high dose haloperidol (1 mg/kg) after 21 days administration compared with the control group, which included both frequency and latency of intromission and ejaculation. Only ejaculation latency was significantly impaired after administration with 0.5 mg/kg haloperidol. Compared with the control group, high dose risperidone (0.5 mg/kg) significantly decreased the frequency of mounting. There were no significant changes in sexual behavior with the lower doses of either haloperidol or risperidone. Sexual behavior was not influenced by any dose of quetiapine. Haloperidol and risperidone, but not quetiapine, could impair sexual competence in a dose-related manner in male rats.

Manipulation of the microbiota of mass-reared Mediterranean fruit flies Ceratitis capitata (Diptera: Tephritidae) improves sterile male sexual performance

The sterile insect technique (SIT) is a method of biological control whereby millions of factory reared sterile male insects are released into the field. This technique is commonly used to combat the Mediterranean fruit fly (Ceratitis capitata, Diptera: Tephritidae). Sterile medfly males are less competent in attracting and mating with wild females, a property commonly linked to the irradiation process responsible for the sterilization. As bacteria are important partners in the fly's life cycle, we used molecular analytical methods to study the community structure of the gut microbiota in irradiated male medflies. We find that the sterilizing irradiation procedure affects the gut bacterial community structure of the Mediterranean fruit fly. Although the Enterobacteriaceae family remains the dominant bacterial group present in the gut, the levels of Klebsiella species decreases significantly in the days after sterilization. In addition, we detected substantial differences in some bacterial species between the mass rearing strain Vienna 8 and the wild strain. Most notable among these are the increased levels of the potentially pathogenic species Pseudomonas in the industrial strain. Testing the hypothesis that regenerating the original microbiota community could result in enhanced competitiveness of the sterile flies, we found that the addition of the bacterial species Klebsiella oxytoca to the postirradiation diet enables colonization of these bacteria in the gut while resulting in decreased levels of the Pseudomonas sp. Feeding on diets containing bacteria significantly improved sterile male performance in copulatory tests. Further studies will determine the feasibility of bacterial amelioration in SIT operations.

Effects of exercise on male copulatory behavior after β-adrenoreceptor blockade

Chronic activity-wheel running enhances male copulation and is associated with brain noradrenergic adaptations that may be modulated by the neuropeptide galanin (GAL). When injected into the medial pre-optic area (MPOA) of the hypothalamus, norepinephrine facilitates, and the β-adrenoreceptor antagonist propranolol inhibits, male copulation. The present experiment tested whether chronic exercise mitigates copulatory decrements induced by adrenergic blockade in the MPOA. It was hypothesized that 3 weeks of activity-wheel running would (1) reverse deficits in male copulatory performance and (2) increase GAL mRNA in the MPOA after β-adrenoreceptor blockade with propranolol. Materials and methods Long–Evans male rats were randomly assigned to three experimental groups: sedentary/propranolol, activity-wheel/propranolol, and home-cage control. Animals were chronically administered propranolol in saline vehicle (6 μm/day) via an osmotic mini-pump connected to a cannula implanted into the third ventricle. After 3 weeks of activity-wheel running, rats underwent copulatory testing. After rapid decapitation 24 h later, rat brains were analyzed utilizing in situ hybridization histochemistry for GAL mRNA in the MPOA. Results Chronic exercise mitigated reductions in the percentage of males that intromitted and ejaculated after propranolol treatment, but there was no effect of exercise on GAL mRNA. Conclusion The findings are consistent with noradrenergic adaptations in the MPOA that facilitate male copulation after wheel running independently of GAL mRNA expression.

Perineal striated muscles: Anatomy, spinal motoneurons, and participation on copulatory behavior in male rabbits (Oryctolagus cuniculus)

Despite the importance of rabbits in reproductive studies, little information is available on the anatomy and participation of the striated-perineal muscles in male copulatory behavior. In our study, we describe the gross anatomy of two striated-perineal muscles: the ischiocavernosus (ICm) and the bulbospongiosus (BSm). Both muscles have their origin at the ischiadic arc, but the ICm is inserted into the penile crura and the BSm onto the ligamentum suspensorium of the penis. The motoneurons of both muscles were identified using retrograde labeling with horseradish peroxidase coupled to wheat-germ agglutinin. Motoneurons were dispersed in the lower-lumbar and upper-sacral spinal-cord segments, instead of being aggregated in the neuronal nucleus as in other species: the rat, mouse, gerbil, cat, and man. Bilateral dennervation of the ICm or BSm or both in sexually experienced male rabbits did not affect copulatory variables measured at 10, 20, and 30 days after surgery. However, muscular dennervation produced extravaginal ejaculations in 42% of copulatory tests and no ejaculation in 7% of tests, although male pelvic thrusting occurred. These results suggest the participation of the ICm and BSm perineal muscles in penile orientation during copulation but not in seminal emission as described in other mammalian species.

Sleep deprivation affects sexual behavior and tyrosine hydroxylase (TH) levels in sexually experienced male rats

Paradoxical sleep deprivation (PSD) produces alterations in dopaminergic systems and also modifies sexual behavior. In this work we evaluated PSD effects on the sexual response and tyrosine hydroxylase (TH) expression in dopaminergic pathways related to sexual behavior of naive and sexual experienced rats. Male Wistar rats had their sexual behavior evaluated in 6 copulatory tests, with a 4 days interval. In these tests, the animals interacted with a receptive female and parameters that compose each component of the male sexual reply (initiation, arousal and ejaculation) were evaluated. After the 5th test, the animals were randomly divided in 2 groups, control and PSD, and 96 h later they were submitted to the last copulatory test. PSD facilitated the excitatory and the ejaculatory component, increasing the copulatory efficiency. In addition, reduced mount frequency and ejaculation latency were observed. The temporal patterning of the sexual behavior was modified, with reduction in the number of mount bouts. PSD per se was not able to modify TH levels, but in PSD sexual trained rats, an increase in the number of TH-immunoreactive cellular bodies in all dopaminergic areas evaluated was detected. Our data suggest that PSD facilitates the sexual response and this facilitation combined to sexual training could be the consequence of increased TH levels in dopaminergic pathways related to sexual reply.

The effect of acute bupropion on sexual motivation and behavior in the female rat

Recent clinical studies have suggested that the atypical antidepressant, bupropion (Wellbutrin), may stimulate sexual desire in women. Two experiments were conducted, testing the effect of acute bupropion administration on the sexual motivation and copulatory behavior of female rats. In the first experiment, 63 sexually-experienced, female Long–Evans rats were tested in a runway for their motivation to approach an empty goalbox, a nonestrous female, and an adult male. Both latency to approach and time spent in close proximity to the targets were used as dependent variables. Subjects were tested in both a nonestrous (OVX) and estrous (OVX + 15 μg estradiol + 500 μg progesterone) state, and following administration of 0.0, 7.5, or 15 mg/kg bupropion hydrochloride (subcutaneous, 45 min prior to testing). Results indicated that pre-treatment with ovarian hormones significantly increased the sexual motivation of the subjects. Bupropion treatment had no significant effect, either stimulatory or inhibitory, on subjects' socio-sexual motivation. In the second experiment, 60 female subjects were paired with an adult male for a thirty-minute copulatory test. Subjects were tested under one of three hormonal conditions: nonestrous (no hormones), 15 μg estradiol, or 15 μg estradiol + 500 μg progesterone. Subjects were also pre-treated with either physiological saline or 15 mg/kg bupropion. Results indicated that while hormonal administration had a strong effect on female sexual behavior, bupropion treatment did not significantly affect either lordosis or the emission of hop-darts. Males paired with bupropion-treated females successfully achieved a greater number of ejaculations and demonstrated significantly shortened post-ejaculatory intervals. It is possible that bupropion treatment enhanced female attractiveness.

The Effects of Activity-Wheel Running After β-Adrenoreceptor Blockade on Copulatory Behavior and Galanin mRNA in the Medial Preoptic Area and Locus Coeruleus in Male Rats

Copulatory performance of male rats is facilitated by acute injection of nor adrenaline, and inhibited by β-adrenoreceptor blockade, in the medial preoptic area (MPOA). Studies in our laboratory have shown that chronic activity-wheel running is associated with enhanced male copulation and noradrenergic adaptations that are plausibly modulated by the neuropeptide galanin (GAL). The purpose of this experiment was to investigate whether three weeks of activity-wheel running would increase male copulatory performance and GAL mRNA in the MPOA and locus coeruleus (LC) after β-adrenoreceptor blockade with propanolol. MATERIALS AND METHODS: Long-Evans rats (N=48) were assigned in a 2 exercise condition (wheel running vs. sedentary) × 2 drug treatment (propanolol vs. saline) factorial design or to a home cage control group (n=7). Animals were chronically administered saline or propanolol in saline vehicle (6um/day) via an osmotic mini-pump connected to a cannula implanted into the third ventricle. After three weeks of activity-wheel running, rats underwent copulatory testing. 24 hours later, after rapid decapitation, rat brains were analyzed utilizing in-situ hybridization histochemistry for GAL mRNA in the MPOA and LC. RESULTS: There was a main effect of drug treatment on GAL mRNA in the MPOA (p <.05) but no other main effects or interactions between drug treatment and wheel running. Contrary to expectations, animals treated with saline had lower GAL mRNA in the MPOA compared with the propanolol and home cage groups, which did not differ. Similarly, wheel running was lower by week 3 in animals treated with saline compared to propanolol (p <.03). Despite abnormally low rates of copulation in the saline groups, the percentage of wheel runners treated with propanolol that achieved an ejaculation (50 %) was higher compared to other experimental groups (7%), (Z = 2.85, P < .05). CONCLUSION: Propanolol treatment appeared to normalize expression of the gene that encodes prepro-galanin in the MPOA after chronic cerebroventricular saline administration. Similarly, propanolol treatment normalized ejaculation rate, but not other features of male copulatory performance, after chronic wheel running.

Effects of aqueous extract of Alpinia calcarata rhizomes on reproductive competence of male rats

This study examined the effects of rhizomes of Alpinia calcarata Roscoe (Zingiberaceae) on male sexual competence and fertility, using a hot water extract (HWE) and rats. Different doses of HWE (150, 250 and 500 mg/kg) were orally administrated to male rats and their sexual behaviour was monitored (for 15 min) 3 h later using receptive females. Fertility was determined in a separate group (with the highest dose) using a noncompetitive copulation test. In the sexual behaviour study, the HWE impaired the number of rats ejaculating and markedly prolonged the latency for ejaculation. Further, the number of rats mounting and intromitting, and the latencies for mounting and intromission were inhibited. Collectively, these observations indicate a strong aphrodisiac action. The other parameters remained unchanged indicating non-impairment in libido, sexual arousability, sexual vigour and sexual performance or penile erectile ability. However, a slight impairment was evident in sexual motivation (with the highest dose) in a partner preference test. In the fertility test, HWE induced profound oligozoospermia but fertility was uninhibited. The highest dose of HWE also elevated the serum testosterone level and the number of spontaneous penile erections rapidly and markedly. Further, the HWE was nontoxic. It is concluded that A. calcarata rhizomes possess a strong and safe oral aphrodisiac activity.

Sexual fetishism in a quail (Coturnix japonica) model system: Test of reproductive success.

In the present study, the authors explored the reproductive consequences of fetishistic behavior in a previously developed animal model of sexual fetishism (F. Köksal et al., 2004). Male domesticated quail (Coturnix japonica) received sexual conditioning trials in which a terrycloth object (the conditioned stimulus [CS]) was paired with the opportunity to copulate with a female quail (the unconditioned stimulus). Approximately half of the male quail came to copulate with the CS object and were considered to have developed fetishistic behavior. Each of the male quail was then tested with a female quail, whose eggs were incubated to determine rates of fertilization. The CS object was present for 30 s before and during the copulation test. Fetishistic male quail were slower to achieve cloacal contact with the female quail and showed less efficient copulatory behavior. However, they fertilized a greater proportion of eggs than nonfetishistic male quail. These results are unexpected from previous studies of the relationship between reproductive success and copulatory behavior and are discussed in terms of how fetishistic behavior directed toward an inanimate object may modify male-female interactions.

Female meadow voles, Microtus pennsylvanicus, cause their mates to ejaculate outside their reproductive tract

We report the first case of sperm wasting produced by females running away just before a male ejaculates. Consequently, males ejaculate outside the reproductive tract of the female. This behavior was observed at least once in 32.14% of 112 copulatory tests of meadow voles, Microtus pennsylvanicus. We found a negative correlation between percentage of external ejaculations experienced by males and the number of sperm allocated within the female reproductive tract. Thus, females may limit the fertilizing capacity of non-preferred males by causing them to ejaculate externally. The occurrence of external ejaculations was not affected by cues of other males, male body mass, female sexual experience, or male sexual experience. Our results expand the growing view that females may be active participants in copulatory behavior and largely determine the fate and use of sperm.

Classical conditioning increases reproductive success in Japanese quail, Coturnix japonica

We examined the adaptive significance of learning by determining whether classical conditioning increases reproductive success. Male and female quail received conditioning trials in which a small light (conditioned stimulus or CS) signalled access to a copulation partner. After this learning experience, pairs of subjects received a single 2-min (experiment 1) or 5-min (experiment 2) copulation test during which both the female and the male, only the female, only the male, or neither bird received the conditioned stimulus signalling access to a copulation partner. Signalling the copulatory episode for both the female and the male significantly increased the percentage of fertilized eggs that were produced and increased the efficiency of the copulatory behaviours that occurred. Presenting the CS to just one or the other sexual partner had no effect. These findings demonstrate that classical conditioning can enhance reproductive success, but the effect requires that both the male and the female be able to anticipate a sexual encounter.