Attraction of beagles to conspecific urine, vaginal and anal sac secretion odors

Attraction of male and female Beagles to conspecific urine, vaginal and anal sac secretion odors was examined in four experiments. Males spent more relative time investigating female urine odors than odors of vaginal or anal sac secretions. Sexually experienced males, but not sexually inexperienced ones, spent more time investigating estrous than diestrous female urine and vaginal odors. Anal sac secretions from estrous bitches were not more attractive to males than those from diestrous bitches. Estrous females spent no more time than diestrous ones in the investigation of male anal sac secretion and urine odors. Male urine and anal sac secretions elicited little investigation from male conspecifics. Females spent more time investigating female urine odors than female anal sac or vaginal secretion odors, and exhibited a slight general preference for diestrous over estrous stimuli. A positive correlation between the odor investigation times of this study and investigation times of comparable animals to conspecifics in a social situation suggests odor preferences are relatively good indicators of social preferences, and vice versa, in this breed.     

Neonatal organization of adult partner preference behavior in male rats

Male rats were castrated or sham castrated shortly after birth. Castrated males were then injected every other day on days 0-10 with testosterone propionate (TP, 0.5 mg), dihydrotestosterone propionate (DHTP, 0.5 mg) or the oil vehicle (0.05 ml); sham-castrated males received oil injections. In adulthood, when substituted with DHT, DHT + E2, or T (silastic implants), sexual partner preference was measured in an automated open field (AOF), in which wire mesh prevented sexual interaction with incentives, and in a 3-compartment box (3-CB), in which sexual interaction with tethered incentives was possible. Choices were an estrous female and a nonestrous female or an estrous female and a sexually active male. In adulthood, following long-term treatment with DHT or DHT + E2, the males did not show any partner preference when sexual interaction with incentives was prevented. Following sexual experience with an estrous female these males preferred the estrous over the nonestrous female, although this change could also be due to long-term hormone treatment. In the 3-CB, a clearcut preference emerged for the estrous female over the nonestrous conspecific, although the neonatally DHTP- or oil-treated males scored lower than the neonatally TP-treated or control males. Six weeks after removal of the hormone implants, when tested in the 3-CB (estrous female vs. active male), the males showed no partner preference. Unexpectedly the control males showed a low preference for the active male. Three weeks T-treatment made all males show a preference for the estrous female (in 3-CB).(ABSTRACT TRUNCATED AT 250 WORDS)     

Sexual behavior of the naive male mouse as affected by the presence of a male and a female performing mating behavior.

Sexually naive male mice allowed to observe conspecifics engaged in copulation later exhibited a preference (p<0.01) for the odor of estrous females over that of diestrous females. They also mounted estrous females more frequently than diestrous females (p<0.001). Naive males observing noncopulating pairs or isolated females exhibited a preference (p<0.01) for the odor of diestrous females over that of estrous females but showed no difference in mounting behavior in the presence of estrous versus diestrous females.     

Sex-dependent antidepressant effects of lower doses of progesterone in rats

Major depression is more prevalent among women than men, and progesterone might be involved in the mechanisms that generate these differences. Progesterone is clinically used for women in several reproductive events, but its antidepressant effect is unclear. Animal studies showed the interference of progesterone on depressive behaviors of rodents, but they are inconclusive, and no study compared different treatment durations. This study investigated the antidepressant effect of low doses of progesterone in male and female rats under acute or chronic administration. Male and female Wistar rats in different phases of the estrous cycle were acutely administered different doses of progesterone (0.0, 0.4. 0.8 and 1.2 mg/kg) and tested in the forced swimming test (FST). The lowest dose of progesterone (0.4 mg/kg) was chronically administered during two complete estrous cycles and diestrous II female and male rats were tested in the FST. Progesterone decreased depressive-like behaviors only in chronically treated diestrous II female rats and increased immobility in male rats. This low dose of progesterone did not interfere in the hormonal cycling in female rats. Results also showed that diestrous II female rats had greater immobility than male rats in the FST. The greater immobility of diestrous II female rats shows that rats in this estrous phase present more depressive-like behaviors that may be associated with their lower serum levels of progesterone. We showed that progesterone chronically administered at low doses reverses these depressive-like behaviors and has an antidepressant effect during the diestrous II phase of the estrous cycle.     

On the organization of partner preference behavior in female Wistar rats

The possible prenatal organizing effects of testosterone (T) on adult sexual partner preference, i.e., sexual orientation in female rats, were studied through prenatal exposure (days 11-22) of female fetuses to the antiandrogens flutamide (Sch 13521; 4'-nitro-3'-trifluoromethylisobutyranilide; 5 or 10 mg/day; Experiment 1) or anandron [RU 23908; 5,5-dimethyl-3-(4-nitro-3-(trifluoromethyl)phenyl)- 2,4-imidazolidinedione; 35 mg/kg/day; Experiment 2]. The neonatal organizing effects of T were further studied by giving T, dihydrotestosterone (DHT) or oil within 9 h after birth to female pups (Experiment 3). In adulthood sexual orientation was ascertained, after ovariectomy followed by hormone treatment, in an automated open field (AOF), with stimulus animals behind wire mesh, and in a 3-compartment box (3-CB), with stimulus animals tethered. When given the choice between an estrous female and a sexually active male in the AOF, flutamide females, as well as controls, preferred the male partner. After long-term T treatment and 3 weekly pair-tests with an estrous female, flutamide females as well as controls switched their preference to the estrous female partner. In anadron females similar results were obtained. Thus the prenatal antiandrogens had no significant effect on sexual orientation in female rats. This suggests that adult sexual orientation in female rats is not organized prenatally through endogenous T. The change in preference after sexual experience corroborates earlier findings from our laboratory. When given the choice between an estrous female and a sexually active male in the 3-CB (sexual interaction with incentives possible), neonatally DHTP-treated females preferred the male; neonatally TP- or oil-treated females showed no preference.(ABSTRACT TRUNCATED AT 250 WORDS)     

Estrous cycle in ob/ob and ovariectomized female mice and its relation with estrogen and leptin

Hormones like leptin and estrogen have been suggested to increase energy expenditure and modulate estrous cycle. The aim of this study was to investigate the stages of estrous cycle in mouse models with contrasting leptin and estrogen levels. Estrous cycle of wild type (WT), WT ovariectomized (OVX), ob/ob and ob/ob OVX was observed by obtaining vaginal smear and staining with Papanicolaou (PAP) procedure. Quantitative analysis showed cellular morphology and predominance of cellular content across the estrous cycle. Microscopical and quantitative counts showed a 4-5 day regular cycle in WT mouse, WTOVX were acyclic, infertile and hardly showed any cells, ob/ob and ob/ob OVX were both acyclic, infertile and were at persistent estrous or persistent metaestrous phase. Enzyme-Immunometric Assay results showed that leptin levels were about 3 fold higher in WTOVX than WT mouse (p < 0.0001) with β-estradiol values being negligible in WTOVX. The β-estradiol levels for ob/ob and WT were similar. These results suggest that although leptin and estrogen play an important role in the estrous cycle, they are not the sole factor influencing the cycle. It is probable that in the absence of leptin and decrease in sex steroid hormones with increase in acyclicity, the central nervous system probably interprets the circulation as absence of energy stores and shuts down reproduction indicated by the changes in the estrous cycle.     

Exposure to PCB 77 affects partner preference but not sexual behavior in the female rat

In rats, exposure to the polychlorinated biphenyl congener 3, 4, 3′, 4′-tetrachlorobiphenyl (PCB 77) affects the brain and behavior of the offspring as well as the maternal behavior of the dams. In the present study, a cross-fostering design was used to examine the effects of pre- and/or postnatal exposure to PCB 77 on sexual behavior and partner preference in female rats, and to determine the role of altered maternal behavior in the mediation of these effects. Pregnant rats were treated with oil or PCB dissolved in oil (2 mg/kg b.w.) on gestation days 6-18 and then given pups that had been exposed to either the oil vehicle or PCB during gestation. As adults, the female offspring were tested for partner preference (that is, whether they preferred to spend time with a sexually receptive female or a sexually active male) and sexual behavior. None of the treatments affected female sexual behavior. However, both double exposure and postnatal exposure diminished the animals' preference for a male over a female stimulus, but partner preference was not affected by prenatal exposure alone. There were no significant correlations between the changes in partner preferences due to PCB exposure and the amount of maternal grooming and licking received by the treated litters. Thus, female partner preference is affected by early PCB exposure, and the effects depend upon whether the exposure is in utero or via lactation and may be independent of any effects of the PCB on maternal care.     

Female hamster preference for odors is not regulated by circulating gonadal hormones

Proceptive and receptive behaviors of female rodents, such as golden hamsters, are often regulated by changes in circulating levels of ovarian hormones. However, less is known about how ovarian hormones might regulate female hamster's attraction and preference for volatile odor from males. To evaluate this, we assessed female preference by recording investigation and proximity to male and female volatile odorants in a Y-maze across all days of the estrous cycle (Experiments 1 and 2) or following ovariectomy (Experiment 3). In Experiment 1, female subjects were tested four times, once on each day of their estrous cycle. Females showed a preference for male odors on diestrus day 1 and to a lesser degree on proestrus, but showed no preference on the day of behavioral estrus. Irrespective of cycle day, preference was apparent in the first few days of testing and disappeared by the fourth day, suggesting that repeated testing attenuated female preference. To avoid this problem, in Experiment 2 each animal was tested only on one day of the 4-day estrous cycle. Female preference for male volatile odors over those from females was observed on each day of their estrous cycle, including estrus. Moreover, following gonadectomy (Experiment 3) female hamsters still preferred male volatile odors to those of females. Taken together, this suggests that circulating levels of gonadal hormones do not influence preference for male volatile odors in female hamsters.     

Fluoxetine does not prevent interspecific mating between two hamster species

In a recent study we showed that female Syrian hamsters (Mesocricetus auratus) from a laboratory stock readily mated with male Turkish hamsters (M. brandti). We hypothesized that captivity and/or unconscious selection of the most receptive females by researchers or animal caretakers results in heightened female sexual receptivity and reduces the tendency to reject heterospecific males. To test this hypothesis, we decided to decrease female receptivity by injection of fluoxetine, which increases the levels of serotonin in a number of brain loci, including areas involved in mediating sexual behavior, and determine whether such a decrease in receptivity would result in better discrimination of heterospecific males and rejection of such males as mates. We treated estrous female Syrian hamsters with 20 mg/kg fluoxetine or vehicle and paired them with both a conspecific and a heterospecific male (Turkish hamster) in two sequential tests. All females showed similar behavior — they exhibited lordosis toward both conspecific and heterospecific males. We did not observe any sign of aggression. Latency to display lordosis and the duration of lordosis were not affected by fluoxetine. Fluoxetine thus did not have an effect on the behavior of females toward conspecific or heterospecific males. Independent of treatment (fluoxetine or vehicle injection), females did display lordosis significantly faster and for a longer duration in the presence of a conspecific male, even though these differences were small.     

Sexual function,satisfaction with life and menopausal symptoms in middle-aged women

Purpose

To assess sexual function, satisfaction with life (SWL), and menopause-related symptoms among mid-aged Spanish women.

Materials and methods

Cross-sectional study of 260 women, aged 40–59, attending the public gynecology consultations completed the 14-item Changes in Sexual Functioning Questionnaire (CSFQ-14), the SWL Scale (SWLS), the Menopause Rating Scale (MRS), and a socio-demographic questionnaire.

Results

Median [inter quartile range] age was 47 [8.0] years, 87.7% had a stable partner, 27.0% were postmenopausal, and 53.9% had increased body mass index (BMI). The prevalence of sexual dysfunction was 46.5% (CSFQ-14 score ≤ 41). Postmenopausal status was associated with lower CSFQ-14 scores (worse sexual function) and severe menopausal symptoms whereas there were not significant differences in SWLS scores. CSFQ-14 scores correlated with SWLS (p < 0.04), and inversely correlated with menopausal symptoms (p < 0.02). Multiple linear regression analysis model predicted 26.6% of the total CSFQ-14 score variance, and higher scores (better sexual function) were correlated with better SWL, and inversely correlated to female age and worse menopausal symptoms. A second model predicted 38.4% of the SWLS score variance. The SWLS score correlated with the total CSFQ-14 score and BMI, and inversely correlated with economical problems, female tobacco use, lack of healthiness, menopausal symptoms, not having a partner, and partner's lack of healthiness.

Conclusions

Lower sexual function was related to low SWL, age and menopausal symptoms while low SWLS score was related with economical problems, smoking, menopausal symptoms, and partner factors.     

The effects of sexual experience and estrus on male-seeking motivated behavior in the female rat

Ovariectomized (OVX) female rats were trained to traverse a straight alley and return to a goal box where they had previously encountered a male rat, a female rat or an empty goal box. The time required to run the alley was used as an index of the subjects' motivation to re-engage the goal box target. Subjects were tested in both estrus and non-estrus, first sexually naïve and then again after sexual experience. Female rats ran most quickly for a male target, most slowly for an empty goal box, and at intermediate speeds for a female target. Sexual experience tended to slow run times for all but male targets. Estrus enhanced approach behavior for males and an empty goal box, but tended to slow the approach toward females, both before and after sexual experience. This latter finding was further investigated in a second experiment in which sexually naïve OVX females were tested during estrus and non-estrus in a locomotor activity apparatus, a runway with an empty goal box, and an open field. Estrus produced no changes in spontaneous locomotion either in the activity box or the open field, but decreased run times in the alley and increased the number of center-square entries in the open-field. Thus, estrus produces increases in sexual motivation that selectively enhance exploratory, presumably male-seeking behavior, but not simple spontaneous locomotion.     

The staggerer gene curtails the reproductive life span of females

Three studies were undertaken to investigate some features of the reproductive activity of female staggerer mice of the C57BL/6 strain. It was found that in the staggerer female, (1) vaginal opening and onset of vaginal estrous cycling were delayed; (2) the vaginal estrous cycle was irregular and characterized by abnormally prolonged diestrous and estrous phases, and (3) the reproductive life span of the mutant female was confined to a 3-month period after puberty. The abnormalities observed in sexual functions suggest a specific influence of the staggerer gene on reproductive activity.This work was supported by grants from the Centre National de la Recherche Scientifique (France) and the Naturvetenskapliga Forskningsrådet (Sweden).     

Effects of prenatal stress on sexual partner preference in mice

Three-month old, male Swiss Webster mice were born to either control dams or dams who had been prenatally stressed with light, heat, noise and handling during the last week of gestation. As adults, male offspring were tested on sexual partner preference and sexual behavior (mounting, intromissions and lordosis) with a sexually experienced male stimulus animal and a stimulus estrous female. In comparison to males born to control dams, prenatally stressed males showed a sexual partner preference for the sexually active male as demonstrated by a negative partner preference score, more and longer visits to the male's compartment, fewer and shorter visits to the female's compartment and longer latencies to and lower frequencies of mounts and intromissions of females. In addition, stressed males showed a greater frequency of lordosis and a higher lordosis quotient than did control males. This study is the first to investigate the effects of prenatal stress alone, without hormonal manipulation, on sexual partner preference using both a partner preference paradigm and measures of sexual behavior such as mounting, intromissions and lordosis. These findings support the suggestion that prenatal stress alone is enough to significantly affect sexual partner preference in male mice.     

Intracerebroventricular infusion of the galanin antagonist M40 attenuates heterosexual partner preference in ferrets.

Gonadectomized, estradiol-treated male and female ferrets (Mustela furo) received intracerebroventricular (i.c.v.) infusions of 4 doses of the galanin receptor antagonist M40 or galanin and were allowed to approach breeding male or female ferrets that were placed behind wire mesh barriers in the goal boxes of a T maze. After i.c.v. infusion of saline, subjects strongly preferred to approach stimulus ferrets of the opposite sex. Male and female subjects approached these preferred stimulus animals on significantly fewer trials after i.c.v. infusion of the 2 highest doses of M40, whereas this drug failed to affect males' coital behavior in separate tests with an estrous female. Endogenous galanin may facilitate neural reward mechanisms that control heterosexual partner preference in both sexes.     

Assessment of subjective sleep disturbance and related factors during female mid-life with the Jenkins Sleep Scale

Objective

To assess sleep disturbance and related factors among mid-aged women.

Methods

This was a cross-sectional study in which 288 women (40–59 years) were requested to complete the Jenkins Sleep Scale (JSS), the 12-item General Health Questionnaire (GHQ-12), the Menopause Rating Scale (MRS) and a general socio-demographic questionnaire containing female and partner data.

Results

Median [interquartile range] age of the whole sample was 47 [8] years. A 62.2% of women were rural residents, 21.2% were postmenopausal, 20.1% were receiving psychotropic drugs, 64.2% had abdominal obesity (waist ≥ 88 cm), and 9.7% reported intimate violence. A 12.8% had an abnormal GHQ-12 score (total score ≥ 3) whereas 14.2% had severe menopause-related symptoms (total MRS score ≥ 17). The prevalence of disturbed sleep (JSS score ≥ 12) was 37.5%. JSS scores displayed significant differences in relation to menopausal status, presence of stress urinary incontinence, use of psychiatric treatment, intimate partner violence, self-perception of healthiness, and partner factors (perception of healthiness, educational level, and regular exercise). Higher JSS scores (disturbed sleep) positively correlated with GHQ-12 and MRS scores, number of co-morbid conditions, body mass index, and female and partner age. Multiple linear regression analysis found that JSS scores correlated positively with somatic MRS scores and with intimate violence, and inversely with partner educational level (r² = 0.375, p < 0.05).

Conclusion

In this mid-aged female sample, disturbed sleep was related to somatic menopause-related symptoms, intimate violence and partner educational level.     

Bilateral damage to the sexually dimorphic medial preoptic area/anterior hypothalamus of male ferrets causes a female-typical preference for and a hypothalamic Fos response to male body odors

Previous studies showed that bilateral lesions of the male ferret's preoptic area/anterior hypothalamus (POA/AH), centered in the sexually dimorphic nuclei present in this region, caused subjects to seek out a same-sex male, as opposed to a female conspecific. Male subjects with POA/AH lesions (which were also castrated and given estradiol) displayed female-typical receptive behavior in response to neck gripping by a stimulus male, implying that subjects' approaches to a same-sex conspecific were sexually motivated. We asked whether the effect of POA/AH lesions on males' partner preference reflects a shift in the central processing of body odorant cues so that males come to display a female-typical preference to approach male body odorants. Sexually experienced male ferrets in which electrolytic lesions of the POA/AH caused bilateral damage to the sexually dimorphic male nucleus (MN) resembled sham-operated females by preferring to approach body odors emitted from anesthetized male as opposed to female stimulus ferrets confined in the goal boxes of a Y-maze. This lesion-induced shift in odor preference was correlated with a significant increase in the ability of soiled male bedding to induce a Fos response in the medial POA of males with bilateral damage to the MN-POA/AH. No such partner preference or neural Fos responses were seen in sham-operated males or in other groups of males with POA/AH lesions that either caused unilateral damage or no damage to the MN-POA/AH. Male-typical hypothalamic processing of conspecifics' body odorants may determine males' normal preference to seek out odors emitted by female conspecifics, leading to mating and successful reproduction.     

Role of androgen, estrogen and sexual experience on the female rat's partner preference

Virgin ovariectomized rats were implanted with Silastic tubings containing estradiol (E2, 5 mm), testosterone (T, 30 mm), dihydrotestosterone (DHT, 30 mm), or injected daily SC with the synthetic nonaromatizable androgen, methyltrienelone (R 1881, 5 mg.kg-1) daily for three weeks. Animals were tested for partner preference behavior (staying in the vicinity of a sexually active male, an estrous female or staying elsewhere) before and after they had been tested for feminine and masculine sexual behavior. All naive androgen-treated groups showed a male-oriented preference, while the naive E2-treated females did not show any consistent partner preference. Sexual experience abolished the male-directed orientation of the androgen-treated groups while E2 treatment induced a male-directed orientation. E2-treated females spent significantly longer time elsewhere in both tests compared to the other groups which might be due to insufficient levels of E2. Feminine sexual behavior was seen after treatment with E2 or T but not after treatment with DHT or R 1881. It was concluded, 1) that the effect of treatment with an androgen on the partner preference behavior differs according to whether the females are virgins or sexually experienced, and 2) the effect of the hormone treatment on the partner preference behavior is independent of whether the hormone stimulates feminine sexual behavior.     

Partner preference in male hamsters: steroids, sexual experience and chemosensory cues

This study investigated the effects of gonadal steroids on sexual motivation in male Syrian hamsters, using partner preference as a model. Male hamsters were assigned to 5 groups: control (n=4), Intact-->Orchx (n=8), Orchx-->Orchx+T (n=7), olfactory bulbectomy (BulbX, n=5), and vomeronasal organ lesion (VnoX, n=8). Each male was tested for partner preference before and after sexual experience. Unlike rats, sexually-inexperienced gonad-intact male hamsters preferred the receptive female to a stimulus male. However, sexual experience did not enhance preference for the stimulus female. Castration (Orchx) reduced sexual motivation: Orchx males showed no significant preference for the stimulus female. Subsequently, intact males were castrated (Intact-->Orchx) and Orchx males received a testosterone implant (Orchx-->Orchx+T) to determine the time course of gonadal hormones on partner preference and mating behavior. Partner preference changed significantly in both groups within 6 weeks. In Intact-->Orchx males, preference for the stimulus female decreased while Orchx-->Orchx+T males increased their preference for the stimulus female. However, significant changes in mating behavior preceded the alterations in partner preference. Chemosensory cues are also important for partner preference. After BulbX, preference for the stimulus female significantly decreased. However, VnoX failed to block partner preference. These results show that partner preference may be even more dependent on testosterone than is sexual behavior. Furthermore, while chemosensory cues are essential for sexual motivation, the vomeronasal organ is not required for partner preference.     

Contribution of anal scent gland and urinary odorants to mate recognition in the ferret

Previous research [J. Neurosci. 21 (2001) 5832-5840] showed that ferrets of both sexes require olfactory signals to identify opposite-sex mating partners at a distance. The present experiments assessed the contributions of anal scent gland and urinary odorants to these preferences. Sexually experienced, ovohysterectomized female and castrated male ferrets were injected daily with estradiol benzoate and testosterone propionate, respectively. When tested in an airtight Y-maze, subjects of both sexes preferred to approach volatile odors emitted from opposite- versus same-sex stimulus ferrets that were anesthetized and placed in the goal boxes, regardless of whether the anal scent glands of stimulus ferrets had been surgically removed or left intact. Subjects of each sex showed an equal preference to approach volatile odors emitted from anesthetized opposite-sex ferrets that were scent-gland intact as opposed to descented. Female subjects preferred to approach volatile anal scent gland odorants, as well as urinary odorants from male, as opposed to female conspecifics. Male subjects preferred to approach volatile anal scents from females versus males; however, males showed no preference for female over male urinary odorants. Our results suggest that anal scent gland odorants are sufficient, but not required, for mate recognition in the ferret. Instead, a combination of body odorants including, but not restricted to, those derived from anal scent gland secretions apparently underlie olfactory sex discrimination and partner preference in this carnivore.     

Involvement of neuronal nitric oxide synthase in cognitive impairment in isoflurane-treated rats

The underlying causes of post-operative cognitive dysfunction (POCD) in elderly patients remain to be elucidated. In order to explore possible contributory mechanisms, we tested the effects of isoflurane anesthesia on (i) expression of hippocampal neuronal nitric oxide synthase (nNOS) and (ii) the relationship of changes in nNOS expression to cognitive dysfunction in isoflurane-treated aged rats. Our results indicate that isoflurane treatment leads to significant changes in correct reactions (F = 28.35, p < 0.001), initiative avoidances (F = 29.33, p < 0.001), and total reaction time (TRT) (F = 6.99, p < 0.05) of treated rats in the Y-maze test. Isoflurane-treated rats had fewer correct reactions and initiative avoidances in the Y-maze test 24 and 48 h after 2 h of isoflurane anesthesia compared with control group rats (p < 0.05). TRTs to complete 20 trials of the Y-maze test increased significantly 48 h after 2 h anesthesia. The number of nNOS-positive hippocampal neurons decreased 24 h after anesthesia, corresponding to an increased mean immunostaining grey-scale value. These data show that isoflurane causes a transient decrease in expression of hippocampal nNOS in aged rats during early post-anesthesia stages, and that the transient decrease of nNOS is closely correlated with cognitive impairment in isoflurane-treated aged rats.