Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Copulation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,189 records · Page 66Linked to original sources

Mosquitoes: female monogamy induced by male accessory gland substance.

Male accessory glands were implanted in virgin females of Aedes aegypti. When exposed to males, females copulated readily but were not inseminated; they remained sterile for life. Extract from one male could sterilize more than 64 females. The active principle may be a protein or peptide. Intraspecific transplant prevented insemination in 12 species, including Aedes, Anopheles, and Culex; interspecific transplant gave partial protection.

Aedes↗

Mole rat spalax ehrenbergi: mating behavior and its evolutionary significance.

Mating behavior of the subterranean mole rat, Spalax ehrenbergi, consists of three distinct stages-agonistic, courtship, and copulation. Spalax sexual behavior reflects certain cricetid affinities, some features general in rodents, and others presumably related to its subterranean, territorial life. Within four groups of Spalax ehrenbergi, each with different numbers of chromosomes, recently found in Israel, mating behavior seems to provide partial reproductive barriers. Selective matings between chromosome forms may complement a cytologic isolating mechanism to prevent widespread natural hybridization.

Animals↗

Intromission pattern and species vaginal code in relation to induction of pseudopregnancy.

Mechanical stimulation was used to mimic normal vaginal stimuli during copulation in the mouse; the number and rate of intromissions were crucial influences on reproductive success. The best combinations for the mechanical induction of pseudopregnancy were comparable to those male behaviors normally seen during mating. The behavior of the male coincides with a species-related vaginal code, increasing chances for reproductive success between cospecifics.

Animals↗

Sexual behavior: ultrasonic postejaculatory song of the male rat.

During the refractory period that follows ejaculation, the male rat regularly emits 22-kilohertz vocalizations. These cease after about three-fourths of the total period has elapsed, and this corresponds to an "absolute refractory period" during which the male cannot spontaneously initiate copulation. Similar 22-kilohertz vocalizations occur in other social contexts, and in general they appear to be desist-contact signals.

Animals↗

Anosmia in male rhesus monkeys does not alter copulatory activity with cycling females.

Three adult male rhesus monkeys were tested daily with intact adult female partners over the course of four or five mentstrual cycles. The males were made permanently anosmic by chemical ablation of the olfactory epithelium after the second or fourth cycle was completed. All males continued to display typical cycles of copulation with their partners after the anosmia procedures, with the shortest latencies to ejaculation occurring during the periovulatory phase of the partner's ovulatory cycle. Hence, female attractivity and cyclic copulatory performance of rhesus monkeys are not dependent upon olfactory signals.

Animals↗

Mating in bighorn sheep: multiple creative male strategies.

Rocky Mountain bighorn rams obtained copulations by defending single estrous ewes (tending), fighting tending rams for temporary access to defended ewes (coursing), or moving and holding ewes away from other rams beyond the periphery of a traditional tending area (blocking). Coursing and blocking illustrate a feature of many male alternative mating strategies: the ability of males regularly to create mating opportunities.

Aggression↗

Cooperative display and relatedness among males in a lek-mating bird.

Long-tailed manakins mate in leks and cooperate in multiyear male-male partnerships. An alpha male is responsible for virtually all mating, whereas a beta male assists in the courtship displays. Such altruism by the beta male poses a problem for evolutionary theory because most theoretical treatments and empirical examples of cooperative behavior involve kin selection or reciprocity. Here it is shown that alpha and beta partners are not relatives and that reciprocity is not involved. Instead, direct, though long-delayed benefits to beta males are demonstrated, which include rare copulations, ascension to alpha status, and female lek fidelity. These benefits maintain this unusual form of male-male cooperation.

Alleles↗

Influence of ginseng on mating behavior of male rats.

Experiment on the mating behavior of male albino rats paired with receptive females established that in comparison with control animals, males under the influence of ginseng (a) began ejaculation earlier and repeated the action more often in a 45-minute observation period and (b) deposited more copulation plugs in 10 days. The data suggest that ginseng facilitates the mating behavior of male rats.

Animals↗

Penile pressures and muscle activity associated with erection and ejaculation in the dog.

A needle-tipped polyvinyl catheter or subminiature pressure transducer was implanted in the corpus cavernosum penis (CCP), corpus spongiosum penis (CSP), or bulbus glandis to determine the pressure during coitus in 42 dogs. Silver ring electrodes were implanted in the ischiocavernosus (IC) and bulbospongiosus (BS) muscles to monitor the electromyographic (EMG) activity of these muscles. The CCP pressure increased from 26 mmHg in the quiescent state to 161 mmHg at mild erection of the penis in the presence of a receptive female. During the intromission phase of coitus, the mean peak CCP pressure was 5,296 mmHg in the dogs with implanted catheters and 7,434 mmHg in the dogs with implanted transducers. The CCP pressure peaks during intromission were more in phase with the contractile activity of the IC muscles than with the BS muscles. Anesthesia of IC muscles with lidocaine significantly reduced the CCP pressures and the dogs with low pressures were unable to copulate because of insufficient erection for intromission, which indicated that the IC muscles were the source of energy for the high CCP pressure. The mean peak CSP and bulbus glandis pressures during the intromission phase of coitus were 579 and 1280 mmHg, respectively. The contractile activity of the BS muscles was in phase with the CSP pressure peaks. Anesthesia of BS muscles with lidocaine reduced the peak CSP and bulbus glandis pressures during attempted coitus. The mean rupture pressure of the CCP was 86,615 mmHg.

Anesthesia, Local↗

Sexual swellings of female gibbons.

Female gibbons were observed for labial swellings from March 2002 to August 2003. Data were collected on length of time each female was swollen, changes in swelling period as females matured, and cycle length (number of days between onsets of consecutive swellings). Data were also collected on the behaviour of the males when the females were swollen. There was a significant relationship between age of the female gibbon and number of days she had labial swelling. There was no significant relationship between the age of the gibbon and the cycle length, nor between species (Hylobates agilis albibarbis and Hylobates muelleri) and number of days swollen. Copulation was more common when females were swollen. Swelling in female gibbons may be related to copulatory behaviour and serve to provide the male with some certainty of paternity through fertilisation insurance.

Anal Canal↗

Effects of methaqualone on social-sexual behavior in monkeys (M. mulatta) II. Simultaneously dosed subjects.

In a previous publication, we reported on the effects of 10 mg/kg i.m. injections of methaqualone on behavioral changes in treated animals and untreated members of a well-established colony of 10 rhesus monkeys (Macaca mulatta). The drug showed a biphasic effect, causing more passive behaviors in the first 80-100 min postinjection, followed by either aggression or increased sexual activity. After approximately 2 h, the social status and behavior of all animals returned to predrug levels. In general, affiliative activities increased under the influence of the drug, phenomena somewhat parallel tho those described among humans taking methaqualone in group settings. We also speculated that the drug may have an aphrodisiac potency. In the present experiments, 3 animals were caged together and injected simultaneously with the dose used earlier: an adult but naive male, who had been caged alone for infancy; an adult and subadult female, the 2 latter having had extensive social experience. After establishing baseline behaviors, five experiments with methaqualone were conducted, each lasting 2 h; and after the 2nd and 4th experiments, saline controls were carried out. There was a continuous increase from experiment to experiment in the affiliative behaviors of the animals; but during the saline trials, their behaviors returned nearly to those exhibited during baseline studies. Under the influence of methaqualone, the naive male attempted to copulate, which he achieved by the 4th drug trial; and at the same time he established his dominance. The conclusion was reached that methaqualone, indeed, has aphrodisiac potency, best measured by the time the male spent with erection under the influence of the drug, as compared with no erection during the baseline studies or the saline trials. The biphasic effect of methaqualone on behavior reported in the previous review [1] was also observed during the present experiments.

Agonistic Behavior↗

Immobilization does not inhibit the post-coital ovulatory surge of luteinizing hormone in the rabbit.

Heparinized blood samples were obtained through an indwelling catheter in the central ear artery from sexually mature female New Zealand white rabbits after copulation. Immediately after 1 or 2 matings the female was transferred to a restraining cage; blood samples were taken at intervals while the animal was completely immobilized for 3-5 h or was only immobilized for blood withdrawal. Ovulation was detected by the presence of corpora lutea at laparotomy the following day. Plasma was analyzed for LH by established radioimmunoassay procedures. Immobilization did not inhibit ovulation or the pre-ovulatory surge of LH in either group. These data suggest that immobilization cannot inhibit the reflex release of LH in the female rabbit.

Animals↗

Activation of masculine sexual behavior by intracranial estradiol benzoate implants in male rats.

Intracranial implants of estradiol benzoate (EB) were used to explore sites of action for the activation of masculine copulatory behavior in castrated male rats. In experiment 1, 27 or 30 gauge implants were placed unilaterally throughout the hypothalamus and preoptic area. Dihydrotestosterone (DHT) was administered subcutaneously (s.c.) to each male. 25 of 42 males with EB implants located in the medial anterior hypothalamic-preoptic area (AHPOA) exhibited ejaculatory patterns on at least 40% of the post-implantation tests. In contrast, only 4 of 18 of the males with implants located posterior to the anterior hypothalamic area displayed this level of response. This difference in the proportion of animals responding for each implant group was statistically significant. Seminal vesicle weights were not correlated with the occurrence of copulation. In experiment 2, either EB-filled or empty cannulae were placed unilaterally in the AHPOA. Half of the males of each group also received DHT s.c. Intracranial EB in conjunction with DHT s.c. resulted in a significantly greater frequency of ejaculatory response than any other treatment. Despite significant differences among the groups in seminal vesicle weights, there was no correlation with occurrence of ejaculatory behavior. These results are consistent with the hypothesis that testosterone (T) exerts its effects upon masculine sexual behavior via conversion to estradiol (E2); and that the principal neural site of action is the AHPOA.

Animals↗

Effect of embryonic treatment with estradiol or testosterone on sexual differentiation of the quail brain. Critical period and dose-response relationships.

Japanese quail eggs were injected with estradiol benzoate (EB) after 10, 11, 12, 13, or 14 days of incubation, or were injected on day 10 with one of six dosages of EB or seven dosages of testosterone propionate (TP). EB injected on day 10 of 11 demasculinized the males; as adults they were incapable of copulating in response to exogenous TP. EB injected on day 13 or 14 was without effect, and EB injected on day 12 caused slight demasculinization. The critical period for sexual differentiation of the brain appears to end after about 12 days of incubation in this species. As little as 1 microgram EB reduced masculine sexual behavior. Injection of TP at dosages equal to or greater than 100 micrograms also demasculinized male quail.

Animals↗

Effects of intraventricular infusions of 6-hydroxydopamine (6-OHDA) on pituitary LH release and ovulation in the rabbit.

Repeated infusions of 6-hydroxydopamine (6-OHDA) into the third ventricle of the rabbit brain in dosages shown to depress hypothalamic norepinephrine (NE) by more than 80% failed to block the copulation-induced ovulatory surge of LH release from the adenohypophysis in estrogen-primed, multiparous New Zealand White does. Only when infusion of the neurotoxin produced a basal hypothalamic lesion did it intercept the coital stimulus and prevent LH release. In 5 rabbits the initial infusion of 6-OHDA stimulated an LH surge presumably by activating NE release from noradrenergic nerve endings. The failure of chronic depletion of hypothalamic NE to prevent coitally-induced LH release suggests that the transmitter may normally play only a modulatory role in hypothalamopituitary activation in the reflex ovulator, as has also been proposed for its function in cyclic ovulation in the rat. The results suggest that alternative systems may be brought into play to subserve reproductive mechanisms when hypothalamic NE is chronically depleted.

Animals↗

Influence of male aggression on mating of gorillas in the laboratory.

The frequency of sexual interactions between oppositely-sexed pairs of gorillas tested in the laboratory was directly related to the frequency of male aggression directed toward the female. The data suggest that male aggression stimulated female presenting and copulation, and accounted for mating temporally dissociated from the periovulatory period. Among the great apes tested in the laboratory, the male primarily accounts for mating that is unlikely to contribute to reproduction.

Aggression↗

Breeding season influxes and the behaviour of adult male samango monkeys (Cercopithecus mitis albogularis).

Troops comprising a high density population of samango monkeys (Cercopithecus mitis) in Natal province, South Africa, experienced an influx of adult males during the breeding season. Observation of one troop revealed that these males competed with one another and with two resident males for access to receptive females. Although both sexes initiated copulation, attempts to do so were more often successful if female-initiated. Males did not interact with non-receptive females and there were no recorded attempts at infanticide. Male-male interactions were agonistic in the presence of receptive females and neutral at other times. No ritualized displays of dominance and subordinance were seen. The significance of these observations for male reproductive strategies is discussed.

Animals↗

Social relationships between immigrant and resident bonobo (Pan paniscus) females at Wamba.

Social relations and behaviours of adolescent female pygmy chimpanzees (Pan paniscus) that migrated between unit groups were studied at Wamba, Zaïre. Each immigrant female selected one particular resident female, a 'specific senior female' (SSF) and frequently approached and followed her. Affinitive behaviours (e.g. grooming, genitogenital rubbing) were frequently performed between the immigrant and her SSF. Most affinitive behaviours were more likely to be initiated by the immigrant than by her SSF. The immigrant's relationship with her SSF seemed to facilitate the immigrant's integration into the new unit group. Resident males actively approached and mated with the immigrant females. Copulation also appeared to further the immigrant's stable relationship with the resident males.

Agonistic Behavior↗