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At least 145 records · Page 8Linked to original sources

PubMed1999

Sexual behavior and extragroup copulations in a wild population of common marmosets (Callithrix jacchus).

Sexual behavior and mating patterns are described for 3 free-ranging groups of common marmosets living in a coastal forest in northeastern Brazil. Each group contained 2 breeding females. Within groups, sexual behavior was generally restricted to breeding females and a single behaviorally dominant male. Of 101 mounts and copulations, 24 involved pairings of individuals from 2 different groups. Extragroup sexual behavior was performed by both breeding and nonbreeding group members, and 65% of all adults mounted or copulated with an extragroup individual at least once. Sexual behavior occurred throughout the female reproductive cycle but was significantly more frequent during an 11-day 'conception period'. Thus, while female marmosets show no physical signs of estrus, both males and females likely do have some information about the timing of ovulation. Mating patterns in this population included both polygyny and monogamy and varied between groups and over time.

Animals↗

PubMed1977

Effects of repeated morphine administration on copulation and on the hypothalamic-pituitary-gonadal axis of male rats.

Adult male rats were administered morphine twice a day for 45 days and the effects of morphine on the copulation rate, the weight of various organs, and on the hypothalamic-pituitary-gonadal axis were examined. Morphine administered rats showed a loss of weight, hypertrophy of the adrenals, decreased weight of accessory sex organs, low sperm count, and decreased copulation rate. The contents of the luteinizing hormone releasing hormone in the hypothalamus and the luteinizing hormone in the pituitary remained unchanged. Serum luteinizing hormone and testosterone levels decreased, but serum follicle-stimulating hormone levels increased. These results suggest that morphine inhibits the hypothalamic-pituitary-gonadal axis and causes a diminution in the number of fertilizations of the partner females.

Animals↗

PubMed1992

Effect of (-)-para-fluoro-deprenyl on survival and copulation in male rats.

Six-month old male rats were treated with 0.25 mg/kg, s.c., (-)p-fluoro-deprenyl (n = 40) or salt solution (n = 20) three times a week for 25 months. Three of the 20 saline-treated and 15 of the 40 drug-treated males survived (p = 0.05). Sexual activity of the survivors was tested at the end of the experiment. Three of the (-)p-fluoro-deprenyl-treated 31-month-old males proved to be sexually fully active, though, Wistar rats lose their ability to ejaculate by completing their second year of life. Non-copulator, 13 month old male rats were treated instead of the usually used 0.25 mg/kg dose with 0.01 mg/kg, s.c., (-)deprenyl (n = 9), (-)p-fluoro-deprenyl (n = 9) and salt solution (n = 9), three times a week, for 82 weeks and mating activity was tested weekly. The lifespan of the non-copulators was very short: 102 weeks for saline (n = 9), 106 weeks for (-)deprenyl (n = 8) and 104 weeks for (-)p-fluoro-deprenyl (n = 7). Survival was lightly changed by this very small dose treatment, one (-)deprenyl-treated male and two (-)p-fluoro-deprenyl-treated rats remained alive. The copulatory activity, however, was substantially improved.

Animals↗

PubMed1979

[Supression by copulation of the inhibitory effect of p-chlorophenylalanine on rat ovulation (author's transl)].

The effect of copulating on reflex ovulation was studied in rat. The effect of PCPA (300 mg/kg, i.p.) on ovulation and reproduction was compared by evaluating number of oocytes in tubes, histologic features of ovaries, vaginal cycle, insemination, fertilization and number of embryos per rat. PCPA, administered on 9th and 16th h of the estrus phase, totally inhibits ovulation, stimulates reproductive behaviour and prolongs the estrogenic phase. When the animals are kept in copulatory conditions for 16 or 46 hours, the inhibition induced in ovulation disappears to the extent that 60% of the rats become pregnant though the number of embryos is under that of the control group. The farther the treatment with PCPA within the same cycle in the ovulatory period, the greater the inhibitory effect on ovulation is and the lesser the neutralizing effect produced by reflexes related to copulation. Administration of PCPA at the 16 hour of the diestrus causes a greater increase in the average number of embryos-as compared to administration at the 9 hour. In periods longer than 48 hours before ovulation, the inhibition brought about by PCPA is not suppressed by copulatory conditions kept for 16 or 24 hours and is only neutralized if they are kept during a complete cycle. Those treated with PCPA in the diestrus phase and maintained in copulatory conditions for 46 hours, present a higher average of embryos than those maintained in similar conditions for 16 hours.

Animals↗

PubMed1997

Copulation and sexual congress of Leptorhynchoides thecatus (Acanthocephala).

Pairs of the acanthocephalan Leptorhynchoides thecatus from laboratory infections were observed copulating at 21 days, 5 wk, and 12 wk postinfection (PI) in green sunfish, Lepomis cyanellus. Additionally, copulating pairs of worms from natural infections were observed. In each instance of paired males and females, the male was in 1 pyloric cecum of the fish and the female in another. Each had its posterior end protruding into the intestinal lumen at the point from which the ceca arise. The completely extruded bursa of the male fully enclosed the posterior end of the female in a firm attachment. In 1 instance at 5 wk PI, 2 males were observed in copula. One male had its copulatory bursa completely retracted, and the copulatory bursa of the other male was positioned just as though the mate were a female. Based on these and previous findings, it is concluded that male acanthocephalans mate indiscriminately and often throughout their lives. Habitation of ceca maximizes sexual congress because individuals often are positioned with their posterior ends extending into the intestinal lumen within the small area from which ceca originate. Emigration to find a mate is unnecessary.

Acanthocephala↗

PubMed1982

[Experiments in vitro with Litomosoides carinii (Nematoda: Filarioidea) II. Influence of different sera on the release of microfilariae and experiments on the readiness for copulation of the worms (author's transl)].

When fetal calf serum or human serum is added to the culture medium Tc 199, adult females of Litomosoides carinii release the same amount of microfilariae in vitro as after addition of cotton rat serum. In contrast, in media with serum of Meriones unguiculatus or Mastomys natalensis only a few microfilariae are released; moreover, addition of Mastomys serum immobilizes them. When males and females are kept together, the same amount of microfilariae is released as compared with single females. Worms 4 weeks of age (i.e., about 2 weeks before copulation) maintained in medium Tc 199 with 33% cotton rat serum do not mate (no insemination of the females). However, the females live 18 days (harmonic mean) in vitro and grow on average 5 mm in length (28%) and the males roll up their tails in characteristic manner. Worms 5 or 6 weeks of age kept in pairs for 45 to 6 days in vitro were implanted into cotton rats. In vivo they grew to normal length, copulated and delivered microfilariae into the circulating blood. Females implanted solely into the recipient grew as well but remained sterile; this means that no insemination took place in vitro.

Animals↗

PubMed1981

Duration of copulation and fertility in the mink, Mustela vison.

In mink, restricting the duration of copulation (<or=6 min) results in reduced fertility, either due to too few spermatozoa being ejaculated or defective sperm transport (4). The objective of the present work was to determine the effect on fertility of prolonging mating using a sterile male. When copulation was restricted to 5 min, only 3/14 mink whelped, and in 2 of the 3 cases the litter size was well below normal. The use of a vasectomized male, either before or after the intact male, caused a significant increase both in whelp rate (21/24) and litter size. The beneficial effect of the vasectomized male was still present after 4 hr. It is concluded that in short matings, defective sperm transport is the major factor limiting fertility and that the duration of coitus affects the efficiency of sperm transport.

Journal Article↗

PubMed2006

Courtship and copulation in the adult male green anole: effects of season, hormone and female contact on reproductive behavior and morphology.

Interactions among reproductive season, testosterone (T) and female presence were investigated on the structure and function of forebrain and neuromuscular systems controlling courtship and copulation in the green anole lizard. Under breeding (BS) or non-breeding (NBS) environmental conditions, male green anoles were implanted with either T or blank capsules and exposed to one of three female stimulus conditions: physical, visual or no female contact. T and at least visual exposure to females increased courtship displays (extension of a throat fan, or dewlap), and these effects were greater during the BS than NBS. T also facilitated copulation, and did so to a greater extent in the BS. The hormone increased soma size in the preoptic area (POA) and amygdala (AMY), and in the AMY the effects were greater in the BS than NBS. Cross-sectional areas of copulatory organs and associated muscle fibers were enhanced by T, and more so in the BS than NBS. However, no effects on morphology of dewlap motoneurons or muscles or copulatory motoneurons were detected. Thus, (1) changes in behavior and neural and/or muscular morphology are not always parallel and (2) differences in responsiveness to T exist across seasons and among tissues.

Amygdala↗

PubMed1999

Juvenile hormone titers in virgin and mated Choristoneura fumiferana and C. rosaceana females: assessment of the capacity of males to produce and transfer JH to the female during copulation.

We used a radioimmunoassay (RIA) to assess the effect of mating on juvenile hormone (JH) titer in females of the tortricid moths Choristoneura fumiferana and C. rosaceana. Virgins had undetectable levels of JH in their hemolymph on the 5th day of the pupal stage but titers rose to 1-4 and 0.2-0.5 ng JH II eq./ml, respectively, after emergence. On days 1, 3 and 5 following copulation, females of both species had higher JH titers than virgins of the same ages, with the greatest difference between virgin and mated females observed on day 3 for C. fumiferana and on day 5 for C. rosaceana. This increase was apparently not the result of a male-to-female transfer of JH during copulation since: (i) the accessory sex glands (ASGs) of males of both species displayed a very limited ability to convert JH acid into JH, (ii) ASGs produced no JH when incubated in vitro in the presence of L-[methyl-(3)H]-methionine, (iii) ASGs of males injected with L-[methyl-(3)H]-methionine 24 h prior to dissection contained no JH-associated radioactivity, and (iv) freshly formed spermatophores dissected out of females mated to similarly injected males contained no trace of radioactive JH. In addition, the JH content of ASGs and spermatophores, as measured by RIA, was not higher than that of virgin-female hemolymph, on a per-mg basis. However, in contrast with earlier findings in other species of moths, the CA of male C. fumiferana and C. rosaceana maintained in vitro in the presence of tritiated methionine produced and released JH I, JH II and JH III in quantities and proportions similar to those reported for female glands.

Journal Article↗

PubMed2000

Brain control of mating behavior in the male cricket Gryllus bimaculatus DeGeer: the center for inhibition of copulation actions.

We re-examined the functional role of the brain and suboesophageal ganglion (SOG) in inhibiting mating behavior in the male cricket Gryllus bimaculatus DeGeer. Experiments were conducted by using mimetic stimulation to elicit copulation actions. To induce a change in the male internal state from a sexually responsive state to a sexually unresponsive state in the mating stage, noxious stimulation, head injury and leg pinching were used. Males that sustained a head injury became sexually unresponsive but became responsive as soon as the brain was removed, while males that underwent the same treatment remained unresponsive after the SOG was destroyed by sectioning. The inhibitory effects of the brain were also demonstrated by the fact that further removal of the SOG in the decerebrated males did not change their copulatory responsiveness, while removal of the brain in SOG-sectioned males markedly increased copulatory responsiveness. Furthermore, decerebrated males did not become sexually unresponsive by leg pinching, while SOG-sectioned males that had recovered sexual responsivenss, did. These results suggest that the brain, and not the SOG, plays a key role in the inhibition of copulation in the male cricket during the mating stage.

Journal Article↗

PubMedDate not supplied

[The role of testosterone undecanoate in correcting disorders of the copulative function].

Testosterone andecanoate (andriol) was used for treatment of copulative dysfunction in 18 young and middle-aged males in a dose 160 mg/day (a 10-12-day treatment course) or 40-80 mg/day (up to 6 week maintenance course). Clinical responses concerning such sexual symptoms as libido, erection, ejaculation and orgasm were achieved in most of the patients. Pretreatment blood levels of testosterone were not decreased. The treatment aroused these levels which persisted higher that pretreatment ones for 3 months. Estradiol was slightly higher after the treatment. Andriol is recommended for treatment of copulative dysfunction in young and middle-aged males.

Adult↗

PubMed1993

Estrus termination following copulation in female guinea pigs.

In the female guinea pig, estrus is inhibited after copulation. This study explored the role of the endocrine status of the male on the termination of the lordosis response in females. Ovariectomized females were treated with estradiol benzoate and progesterone to induce estrus and were then mated with males when the males were intact, castrated, and castrated and treated with testosterone propionate (TP). Lordosis responses were recorded prior to and following mating. Females who received an ejaculation from a castrated male remained sexually receptive longer than the females mated with intact males, or those males that were castrated and treated with TP. These results support the hypothesis that the factor(s) responsible for termination of estrus in females are found in the ejaculate of the male and are testosterone dependent.

Animals↗

PubMed1989

The effects of intrathecal administration of the dopamine agonist apomorphine on penile reflexes and copulation in the male rat.

Relatively high doses of systemically administered apomorphine inhibit penile reflexes. It is possible that these inhibitory effects are due, at least in part, to actions of apomorphine on the lumbosacral spinal cord. The present experiments examined this possibility by injecting apomorphine (10 and 50 micrograms/5.0 microliters vehicle) into the lumbosacral subarachnoid space through chronic, indwelling cannulae. Such injections impaired ex copula penile reflexes, slowed the rate of copulation, and decreased the number of intromissions preceding ejaculation. These results suggest that lumbosacral cord dopamine receptors may normally regulate male sexual performance.

Animals↗

PubMed1976

Deleterious effects of copulation in Drosophila females as a function of growth temperature of both sexes.

In Drosophila females, copulation always results in a reduction of longevity but the gravity of the phenomenon varies according to growth temperature. The harmful effect of adult males, or aggressiveness, is maximum when growth took place at a middle temperature. Female sensitivity, on the other hand, is at a maximum when larvae were reared at exteme, low or high, temperatures.

Aggression↗

PubMed1975

Copulation in spiders: experimental evidence for fatigue effects and bilateral control of palpal insertions.

Male lycosid spiders were prevented from using one palp during the first third of copulation by a sling that we then cut to free the palp. Initial insertion durations of the treated palp were significantly shorter than those shown concurrently by the much-used normal palp; they showed temporal patterning unaffected by use of the normal palp. Data indicate that there are relatively independent control mechanisms for each palp and support the hypothesis that fatigue causes the increased duration of successive palpal insertions. Our data also suggest that normal matings terminate due to maximal use of either palp by the male.

Animals↗

PubMed1991

Microinjection of the dopamine antagonist cis-flupenthixol into the MPOA impairs copulation, penile reflexes and sexual motivation in male rats.

Microinjection of the dopamine antagonist cis-flupenthixol into the medial preoptic area was previously shown to impair male rat copulatory behavior. The present experiments provide further evidence of cis-flupenthixol's inhibitory effects on male sexual behavior. Following microinjections of moderate to high doses of cis-flupenthixol, males exhibited slower copulatory rates and fewer ejaculations in copula, fewer ex copula erections and penile movements, and reduced sexual motivation in an X-maze. Locomotion in the X-maze was not significantly affected. Microinjections of the inactive isomer trans-flupenthixol produced no change in any behavioral measure, indicating that cis-flupenthixol's effects were receptor mediated. We suggest that dopamine receptors in the MPOA influence copulation primarily by regulating reflexive and motivational factors, but not locomotion.

Animals↗

PubMed1992

Opposite influence of medial preoptic D1 and D2 receptors on genital reflexes: implications for copulation.

Dopamine D1 and D2 receptors may synergize with or oppose each other's effects. We suggest that stimulation of D1 and D2 receptors in the medial preoptic area (MPOA) of male rats have opposing effects on genital reflexes. In Experiment 1 a D1 agonist injected into the MPOA increased the number of ex copula erections but decreased the number of seminal emissions. In Experiment 2 a D1 antagonist had the opposite effects (decreased erections and increased seminal emissions), as had a D2 agonist previously. We also suggest that D1 and D2 mechanisms in the MPOA have different thresholds of activation. In Experiment 3 a low dose of the mixed D1/D2 agonist apomorphine increased erections and anteroflexions, an effect blocked by the D1 antagonist. In Experiments 3 and 4 a high dose of apomorphine increased seminal emissions, an effect blocked by the D2 antagonist. Thus, low levels of dopaminergic stimulation may facilitate erections and anteroflexions (controlled by the parasympathetic system and striated muscles) via D1 receptors; higher or more prolonged stimulation may shift to seminal emission (controlled by the sympathetic system) via D2 receptors. This may explain the progression from erectile to ejaculatory mechanisms during copulation.

Animals↗

PubMed1977

Social-olfactory experience and initiation of copulation in the virgin male rat.

Two experiments examined the role of olfactory sensation for initiation of normal copulatory behavior of mature male rats. Experiment 1 compared copulatory performance of peripherally anosmic social isolates with that of intact isolate controls. The results revealed significantly lower mounting, intromission, and ejaculation frequencies of the anosmic group and suggested that nonolfactory cues attain significance via an associative-learning process. Experiment 2 compared three social isolate groups of mature males with varying sexual experience prior to anosmia. Four 1-hr tests were conducted at 5-day intervals. The results indicated comparable copulatory performance of the experienced groups and absence of copulation by the majority of the nonexperienced group. With a 12-day continuous exposure to intact females, all noncopulators eventually impregnated. The results are discussed with reference to the requirement of social experience for initiation of normal sexual performance in the male rat.

Animals↗