Differential rates of exhaustion and recovery of several parameters of male rat sexual behavior.

Sexual exhaustion of the male rat was studied with respect to several copulatory measures. The ejaculatory latency, intercopulatory interval, and intromission frequency demonstrate a U-shaped curve, exhibiting high values for the initial ejaculatory series, falling to a minimum at an intermediate ejaculatory series, and again increasing at exhaustion. The absolute refractory period of the postejaculatory interval (measured at vocalization termination) increases linerly, whereas the relative refractory period (the remaining portion of the postejaculatory interval) is a postively accelerating function. Partial recovery tests demonstrated that the preejaculatory measures and absolute refractory period have substantially returned to baseline values by Day 6, while the relative refractory period is still extended. The significance of these data to the theoretical modeling of sexual behavior is discussed.     

Pharmacological and physiological aspects of sexual exhaustion in male rats

The present article reviews the current findings on the interesting phenomenon of sexual satiety. Knut Larsson in 1956 reported on the development of sexual exhaustion in the male rat after repeated copulation. We have studied the process and found the following results. (1) One day after 4 hours of ad libitum copulation, two-thirds of the population showed complete inhibition of sexual behavior, while the other third displayed a single ejaculatory series from which they did not recover. (2) Several pharmacological treatments, including 8-OH-DPAT, yohimbine, naloxone and naltrexone, reverse this sexual satiety, indicating that the noradrenergic, serotonergic and opiate systems are involved in this process. Indeed, direct neurochemical determinations showed changes in various neurotransmitters during sexual exhaustion. (3) Given enough stimulation, by changing the stimulus female, sexual satiety was prevented, suggesting that there are motivational components of the sexual inhibition that characterizes sexual exhaustion. (4) The GABA antagonist bicuculline, or the electrical stimulation of the medial preoptic area, did not reverse sexual exhaustion. These data suggest, on the one hand, that sexual exhaustion and the postejaculatory interval (which is shortened by bicuculline administration) are not mediated by similar mechanisms and, on the other, that the medial preoptic area does not regulate sexual satiety. (5) The androgen receptor density in brain areas closely related to the expression of masculine sexual behavior, such as the medial preoptic nucleus, was drastically reduced in sexually exhausted animals. Such reduction was specific to certain brain areas and was not related to changes in the levels of androgens. These results suggest that changes in brain androgen receptors account for the inhibition of sexual behavior present during sexual exhaustion. (6) The recovery process of sexual satiety after 4 hours of ad libitum copulation reveals that, after 4 days, only 63% of the males are able to show sexual behavior while after 7 days all animals display copulatory activity.     

Sexual harassment in the context of double male dominance

It has been suggested that numerically male-dominated workplaces propagate cultural norms that support sexual bravado, sexual posturing, and the denigration of feminine behaviour (Sbraga & O'Donohue, 2000 Sbraga, T. P. and O'Donohue, W. 2000. Sexual harassment. Annual Review of Sex Research, 11: 258–285. [Taylor & Francis Online] , [Google Scholar]). These cultural norms are features of normative male dominance, which have been shown to increase the risk of sexual harassment. This implies that the effect of numerical male dominance on sexual harassment may be mediated by the level of normative male dominance in the work environment. The aim of this study was to test this assumption. Our sample consisted of 1295 police women, who filled out an Internet questionnaire. The results suggest that normative male dominance indeed mediates the relation between numerical male dominance and sexual harassment. We add to the sexual harassment literature by building on Gruber's concept of double dominance. Our study helps to make clear why women are at greater risk of sexual harassment in work situations where men outnumber women than in more gender-balanced workplaces.     

Sexual reinforcement in the female rat.

Sexual reinforcement in the female rat was studied in a preparation that allowed continuous operant responding for access to a male rat leading to intromission. Experiment 1 used a high operant level nose-poke response to test the possible reinforcing effects of some components of access to a male. A simple tone stimulus used as a conditioned reinforcer and two odor stimuli, target male bedding and emulsified preputial gland, were tested. None of these contingent events altered responding above or below operant level. Access to the male, which was always accompanied by intromission, immediately increased response rate when it was made contingent upon the nose-poke response. Performance on fixed-ratio schedules was erratic, and response rate was low in comparison to typical food-reinforced responding. An interresponse-time analysis indicated, however, that some effect of the ratio contingency may have been present. In Experiment 2, several modifications of the procedure were tested with the objective of creating a more tractable preparation for behavior analysis. Response type and the hormone delivery method were changed, and 2 target males were used instead of 1. The latter tripled the average number of reinforcers earned in a single session. Differences between sexual and other reinforcers are discussed in terms of procedural, quantitative, and motivational aspects of the sexual reinforcement procedure.     

Self-stimulation and mating behavior in the male rat

Abstract.— A presumed relationship between selfstimulation of the brain and sexual behavior was studied in two experiments. In the first experiment the male rat was allowed self-stimulation during a period of 5 minutes and thereafter transferred to a mating cage with a female. No effects of the self-stimulation were recorded in the mating behavior. In the second experiment the male was allowed one intromission and thereafter presented with a lever for self-stimulation, still having access to the female. The sexual responses were completely inhibited, and selfstimulation at normal rate resumed. It was concluded that there is no necessary link between self-stimulation of the brain and sexual behavior.     

Sexual identity development among ethnic sexual-minority male youths

The current research explores how ethnicity influences sexual identity development. Among 139 sexual-minority male youths, measures of sexual identity development assessed the timing and sequencing of developmental milestones, disclosure of sexual identity to others, internalized homophobia, and same- and opposite-sex relationship histories. Findings demonstrated that participants, regardless of ethnicity, experienced most identity milestones at developmentally appropriate ages, had moderately low levels of internalized homophobia, and became romantically and sexually involved with other males during adolescence. Differences across ethnic groups were found in the timing and sequencing of certain milestones, disclosure of sexual identity to family members, and romantic and sexual involvement with females.     

Sexual free behavior in male rats (Rattus norvegicus).

Male rats (Rattus norvegicus) were given continuous access to estrous female rats for 24 hr each day for 10 days. During the first 12 hr, the rats achieved an average of 10 ejaculations, followed by a 1- to 2-day recovery period with little sexual activity. During the last 7 days, the rats maintained a reasonably stable equilibrium level of 3 ejaculations per day. These occurred predominantly during the dark phase of the diurnal cycle, they frequently occurred in a cluster, and they usually occurred shortly after the introduction of a novel estrous female. Except for quantitative differences, these results are generally consistent with conventional research but systematically extend the generality of the results to the context of the free behavior situation. The availability of sexual activity had no appreciable effect on food and water intake, but it did decrease the amount of running activity.     

Sexual addiction and compulsion: recognition, treatment, and recovery

The management of patients with compulsive sexual behavior requires an understanding of the profile of the sexually compulsive or addicted patient. This article summarizes patient characteristics and their implications for treatment. Data from a study of the recovery of 957 patients who had problematic, sexually excessive behavior are presented. Spanning 5 years, the study shows six distinct stages patients experienced and the clinical activities that were most useful to them. A trajectory of a typical diagnosis and treatment path is provided, as well as important resources for physicians and patients.     

Relationship between mousekilling and conspecific aggression in the male rat

In order to investigate the relationships between mousekilling and conspecific aggression, behavioral variables of killer and nonkiller rats were compared in a “resident-intruder” paradigm, in resident as well as in intruder animals. The occurrence of offensive items (offensive sideways, attack) was significantly higher in killer rats when they were residents; their corresponding opponents displayed more defensive behaviors. No significant difference in aggressive behaviors was noted when the comparison was done in the intruders. These results and those of previous studies suggest that there is a correlation between mousekilling and intraspecific offensive behaviors. Some similarities in the situations where both behaviors are elicited–eg, introduction of an unfamiliar intruder into a familiar environment–may contribute to the existence of such a correlation and the possibility of common mechanisms underlying both behaviors is discussed.     

Sexual experience and preference for males or females in the female rat

The influence of sexual experience on preference behavior was investigated in adult female rats. In the first experiment, preference behavior for sexually active males versus estrous females was investigated in female rats who were experienced with mounting behavior. Preference of these mount experienced females was compared to preference of females who were naive in this respect. Mount experience with estrous females induced a female-directed preference in ovariectomized female rats, irrespective of whether the females were treated with OIL or with testosterone-propionate (500 micrograms TP, injected once 48 h prior to testing). Sexually naive, OIL-treated females did not show a preference for males or females, but TP induced a preference for a male. Individual differences in mount frequency were not correlated with preference behavior. In the second experiment, the influence of experience with feminine sexual responses on preference behavior was investigated. OIL-treated and TP-treated females oriented equally toward males and females when they had been given the opportunity to copulate with males prior to the preference tests. The results strongly suggest that prior sexual experience is an important determinant of preference behavior. The female's behavior during sexual interactions was, however, not predictive of later preference.     

Job stressors, emotional exhaustion, and need for recovery: A multi-source study on the benefits of psychological detachment

This paper examines psychological detachment (i.e., mentally “switching off”) from work during non-work time as a partial mediator between job stressors and low work-home boundaries on the one hand and strain reactions (emotional exhaustion, need for recovery) on the other hand. Survey data were collected from a sample of protestant pastors (N = 136) and their spouses (N = 97). Analyses showed that high workload, emotional dissonance, and low spatial work-home boundaries were related to poor psychological detachment from work during non-work time. Poor psychological detachment in turn predicted high levels of emotional exhaustion and need for recovery. Psychological detachment was a partial mediator between job stressors and strain reactions. This study avoids same-source bias and demonstrates the importance of psychological detachment in the stressor–strain relationship.