Social variables influence female sexual behavior in the musk shrew (Suncus murinus)

The role of social variables in the mediation of sexual behavior was examined in the female musk shrew (Suncus murinus). Two social variables were manipulated: amount of reproductive experience and exposure to male-related chemical cues. Virgin females took significantly longer to achieve receptivity than did sexually experienced females. In addition, exposure to soiled bedding taken from a male's cage for 24-hr prior to testing reduced receptivity latencies in all females. Even a brief (30 min) exposure to male-related cues was effective in facilitating receptivity in virgins. The converse was noted for female aggressive behavior. Virgin females attacked more frequently than experienced females, and preexposure to male-related cues reduced aggressiveness. These findings suggest that social variables play an important role in female sexual behavior in this primitive eutherian mammal.     

Amphetamine and morphine produce a conditioned taste and place preference in the house musk shrew (Suncus murinus)

Rats have been shown to avoid consuming a flavor, but prefer a location, previously paired with amphetamine or morphine. A series of 4 experiments evaluated the hedonic properties of amphetamine and morphine in the house musk shrew (Suncus murinus), an insectivore that (unlike rats) is capable of vomiting when exposed to toxins. Unlike rats, amphetamine (20 mg/kg) and morphine (20 mg/kg) produced both a conditioned sucrose (0.3 M) and saccharin (0.1%) preference in shrews (administered intraperitoneally), when measured by both a 1- and a 2-bottle test. At the same dose, both drugs also produced a place preference in shrews. These results suggest that the potential of rewarding drugs to produce taste avoidance may vary on the basis of the ability of the species to vomit.     

Male-related chemical cues promote sexual receptivity in the female musk shrew

The role of conspecific chemical cues in the activation of sexual behavior was investigated in the female musk shrew (Suncus murinus). In Experiment 1, virgin female musk shrews were exposed to either clean cages or cages recently vacated by an adult male. Regardless of whether the male used for the sexual behavior test was "familiar" to the female (having spent the 24 h exposure in his vacant cage) or "unfamiliar," females exposed to male-related cues received mounts from males significantly sooner than females exposed to clean cages. In Experiment 2, females housed for 24 h in a cage soiled by an adult male allowed males to mount significantly sooner than females housed in a cage soiled by a castrated male, another female, or a clean cage. These results demonstrate that chemical cues, produced exclusively by adult males, promote sexual receptivity in female musk shrews.     

Monoaminergic mediation of female sexual behavior.

Lordotic behavior was facilitated in estrogen-primed female rats by direct application of progesterone or serotonergic or beta-adrenergic receptor blockers to specific telencephalic, anterior hypothalamic-medial preoptic, or posterior hypothalamic sites. Blockade of the alpha-adrenergic system was ineffective in facilitating lordosis, as was the application of the active drugs to control sites in the thalamus or basal ganglia. Female soliciting behavior was not evoked by any of the treatments. It is concluded that the lordotic behavior component of the female rat's estrous behavior pattern is inhibited by a specific central monoaminergic system that also responds to progesterone. Soliciting behavior appears to be mediated by systems that are anatomically, and possibly neurochemically, separable from those regulating lordosis.     

Role of the ultrasonic vocalization of the female rat (Rattus norvegicus) in sexual behavior

Both male and female rats vocalize ultrasonically during mating. Whereas male calls are known to facilitate female proceptive behavior, the female mating call has not been studied beyond spectrographic analysis. In this article, a series of experiments were done to examine the effects of the female's mating call on rat mating behavior. In the first experiment, females copulated with intact males before and after surgical devocalization. In the second experiment, intact females copulated twice with a male: once when they were able to hear and once when they were temporarily deafened with a medical ear mold. In the third experiment, tape recorded ultrasounds were placed in the presence of devocalized females while they were copulating with intact males. In the control condition, tape hiss was presented. In each experiment, it was observed that the female darted more if communication were disrupted (i.e., female devocalized or male deafened). Playback partially reduced darting to control levels. No other behavior was affected consistently across all experiments. Female calls might facilitate self-regulation of mating behavior, or they might focus the male's attention on her proceptive behaviors. It is also possible that the female calls could alter the stimulus properties of the male's behavior, indirectly affecting her own behavior.     

Effects of fluprazine (DU 27716) upon aggressive and sexual behavior of testosterone-treated female rats

Female rats, chronically treated with Testosterone Propionate (TP), were injected with Fluprazine (DU 27716) or saline and tested for social aggression, masculine and feminine sexual behavior. Fluprazine-treated females were less aggressive than saline-treated females, as indicated by a shift from offensive to less offensive parameters of aggression. At the same time, mounting in Fluprazine-treated females was almost totally abolished, both in aggression tests and in tests for sexual behavior. Feminine sexual responses increased during aggressive encounters but were slightly inhibited when females were confronted with sexually active males. Females treated with Fluprazine and tested for mounting with a receptive female showed a substantial increase of offensive aggression directed at the receptive stimulus female. It is concluded that Fluprazine does not selectively inhibit offensive aggression in TP-treated female rats.     

Social isolation inhibits male-like sexual behavior in female hamsters

In the female golden hamster, Mesocricetus auratus, group housing permits the expression of male-like behavioral patterns including mounting and pelvic thrusting toward an estrous stimulus female. Sixty percent of females housed in groups of five showed these behaviors, while singly housed females were rarely observed to show mounting or thrusting. Females weaned at 19 or 35 days of age did not differ in their tendencies to show male-like behavioral patterns. Virtually all observations of mounting and pelvic thrusting behaviors were made on days when the females being tested were in behavioral estrus. These findings differ from previous studies which have reported that masculine behavioral patterns are rare in normal female hamsters. In previous studies females that were evaluated were typically not in behavioral estrus and were not housed for long periods of time with other intact females. Social factors interact with hormonal state to contribute to the expression of male-like behaviors in female hamsters.     

Effects of female odors on the sexual behavior of male hamsters

A series of experiments was undertaken to investigate the effects of removal of several scent glands and scent-producing organs of female hamsters on the copulatory performance of male hamsters. In the first experiment it was shown that males engage in less copulatory activity toward females lacking vaginal secretions than toward females with these odors. Eliminating visual cues by observing pairs under infrared illumination did not change the performance of males toward these two kinds of females. The results of Experiment 2 indicated the importance of flank, ear, and Harderian glands as well as vaginal secretions--males showed the highest levels of copulatory behavior toward females with a full complement of odors and the lowest levels toward those lacking three of four sources of scent. Similar results were obtained in the third experiment in which anesthetized females were used as stimulus animals to increase the importance of chemical cues and to reduce variability due to the behavior of females. The sexual behavior of males was greatest toward females with all sources of scent present, lower toward those lacking vaginal secretions, and still lower toward those lacking vaginal secretions and other sources of odors. In the fourth experiment we asked whether any one of the nonvaginal scent glands was particularly important in stimulating male sexual behavior, but we found no differences in male performance toward females that lacked vaginal secretions or that in addition lacked one of the other scent glands. In the fifth experiment males displayed higher levels of sexual behavior toward vaginectomized females than toward vaginectomized females that had been deodorized by a cleaning procedure, again indicating the importance of nonvaginal odors in stimulating copulatory performance. Thus these experiments demonstrate the importance of vaginal secretions in the sexual arousal of male hamsters, a role for nonvaginal odors in sexual arousal of males, and the lack of necessity of these odors for male copulatory behavior. These results have implications for theories of olfactory communication in mammals and for interpretations of experiments in which lesions of the olfactory system lead to deficits in male copulatory performance.     

Differential influence of stereoisomers of estradiol on sexual behavior of female hamsters

Morphological and behavioral responses to estradiol-17 beta (E2-17 beta) and estradiol-17 alpha (E2-17 alpha) were examined in a series of three experiments. The E2-17 beta augmented uterine growth in hamsters to a greater extent than did E2-17 alpha. Lordosis in ovariectomized adults was elicited by treatment with E2-17 beta but not with E2-17 alpha (each tested in combination with progesterone). When administered neonatally only E2-17 beta disrupted estrous cyclicity in the intact female and induced the ability to mount in ovariectomized, androgen-treated adults. These results suggest the existence of a stereospecific response to estrogenic stimulation in neural tissue comparable with that occurring in the uterus.     

Central progesterone induces female sexual behavior in estrogen-primed intact males rats

Progesterone induced high levels of female lordotic behavior in 10 of 17 intact, estrogen-primed male rats when it was applied directly to the medial preoptic-anterior hypothalamic area. All 17 males previously had shown lordosis when the serotonergic antagonist methysergide was applied to the same central sites. Few males responded to systemic progesterone and none to intracralial cholesterol. Intradiencephalic Metycaine, a local anesthetic, induced lordosis in eight male that previously had responded to central progesterone. These data indicate that estrogen and progesterone act synergistically to induce lordosis in male rats when progesterone is administered directly to sensitive brain sites.     

The influence of male and female best friends on adolescent sexual behavior

Using panel data from a junior high school system in an urban area of Florida, we examine whether adolescents' best same-sex and best opposite-sex friends' sexual intercourse behavior increases the likelihood that respondents who are virgins at round 1 will make the transition to intercourse between rounds of our study. We find no significant influence effects of friends of either sex for black males or females, or white males. In contrast, white females are influenced by the sexual behavior of both their best female friend and best male friend. A virgin white female whose best friends of both sexes were sexually experience at round 1 was almost certain to have sexual intercourse within the two years of our study.     

Mesencephalic participation in the control of sexual behavior in the female rat

Electric stimuli applied to both pudendal nerves evoked field potentials, unit responses, and multiunit responses in the ventrolateral midbrain, in and around the peripeduncular nucleus. Bilateral lesions placed in this region suppressed sexual behavioral responses (lordosis and courting behavior) of ovariectomized rats primed with 5, 10, 100, and 1,000 microgram of estradiol benzoate and 2 mg of progesterone per kilogram of body weight. It is proposed that the region in question represents a relay station for the integration of sensory and endocrine information concerned in the control of receptive sexual behavior in the female rat.     

Early intervention for female sexual identity disturbance: Self-monitoring of play behavior

This study is the first experimental demonstration of sex-typed play behavior change in a young girl with sexual identity disturbance. The 8-year-old child was treated with a self-monitoring procedure combined with a behavioral prompting technique that was gradually faded out. Self-monitoring in the clinic resulted in a high, stable rate of appropriate sex-typed play, and this effect generalized to a different set of sex-typed toys over time. The treatment effects did not generalize to the home environment. The self-regulation intervention was subsequently adapted to the home setting, resulting in a replication of the treatment effects across settings. After the removal of the self-monitoring interventions, a high level of feminine sex-typed play persisted. Pretreatment, posttreatment, and follow-up psychological testing demonstrated a reversal of a pronounced cross-gender identity to a normal female sexual identity.This study was supported by United States Public Health Service research grant MH29945 awarded to Dr. Rekers at the Logos Research Institute, Inc., by the National Institute of Mental Health. Appreciation is expressed to Dr. Vernon Van de Riet for his independent clinical psychological diagnosis.     

The impact of depressive symptomatology on risky sexual behavior and sexual communication among African American female adolescents

Adolescents, particularly African American adolescents, are at high risk for sexually transmitted infections (STIs). The association between psychosocial factors and risky sexual behavior has been well established. However, only a small number of studies have examined the relationship between depressive symptomatology among African American female adolescents, specifically over time. The present study examined depressive symptoms as a predictor of risky sexual behavior, sexual communication, and STIs longitudinally among African American female adolescents between the ages 15 and 21. Binary generalized estimating equation models were conducted assessing the impact of depressive symptoms at baseline on risky sexual behavior and STIs over six- and 12-months follow-up. Age, intervention group, and baseline outcome measures were entered as covariates. The results indicated that high levels of depressive symptoms predicted no condom use during last sexual encounter and multiple sexual partners over six-months follow-up. Depressive symptoms also predicted having a main partner with concurrent partners, high fear of communication about condoms, and sex while high on alcohol or drugs over six- and 12-months follow-up. These findings could be used to inform HIV/STI prevention intervention programs and clinicians providing regular health care maintenance to African American female adolescents engaging in risky sexual behavior.