Sexual behavior in adult gonadectomized female pseudohermaphrodite, female, and male rhesus macaques (Macaca mulatta) treated with estradiol benzoate and testosterone propionate.

Studied the sexual behavior of gonadectomized adult rhesus macaques given no hormonal treatment, treated with estradiol benzoate (EB; 20 μg/day), or treated with testosterone propionate (TP; 10 mg/day). Six experimentally produced female pseudohermaphrodites, 9 long-term castrated males, and 7 ovariectomized females were given 36 pair tests of 10-min duration with 6 ovariectomized, estrogen-primed female partners. 12 tests were given under each treatment condition. Yawning was the only behavior that showed a significant effect across treatments for hermaphrodites and females; the yawning rate was greater with TP treatment. The number of tests during which hermaphrodites showed erections increased significantly under TP treatment. Only one hermaphrodite mounted, but none achieved intromission or ejaculated. Males displayed several significant treatment effects, including increased mounting, intromitting, and ejaculating frequencies under TP treatment. EB had little effect on any of the behaviors in any group. Rates of aggression and grimacing were greater among hermaphrodites than among males and females. Males displayed significantly greater rates of sexual behavior than hermaphrodites or females. As infants and juveniles, these hermaphrodites had displayed social and sexual behaviors characteristic of males; however, as mature adults, their behavior and responsiveness to TP at a dose capable of activating a high level of sexual behavior in castrated males gave little evidence of masculinization. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modifications induced by neonatal steroids in reproductive organs and behavior of male rats.

112 3-day-old male Sprague-Dawley rats were injected neonatally with .01, .1, 1, 10, 100, or 1,000 μg of estradiol benzoate (EB), 10,000 μg of testosterone propionate (TP), or sesame oil; they were subsequently examined for testicular, penile, and accessory organ development. Sexual behavior was evaluated during therapy with fluoxymesterone (FM) and then with TP. EB in dosages greater than 1.0 μg delayed testicular descent, reduced the size and hormone responsiveness of reproductive organs, and decreased sexual behavior in a dose-dependent manner. The 10,000 μg dosage of neonatal TP delayed testicular descent and reduced sexual behavior to levels near those of the 10–200 μg EB groups, but it produced no significant penile or accessory organ changes. Neither reduced peripheral organ development nor inhibited neonatal testicular secretions fully explain reductions in male behavior following large dosages of neonatal TP. Neonatal androgen may reduce the responsiveness of CNS neurons governing male sexual behavior after being converted to estrogen or by directly altering steroid receptor systems. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Steroidal modulation of scent investigation and marking behaviors in male and female ferrets (Mustela putorius furo).

Gonadectomized male and female ferrets (Mustela putorius furo) given either testosterone propionate (TP) or oil vehicle preferred to investigate the side of a test cage previously soiled by a breeding male or female as opposed to a clean side. Male and female ferrets receiving TP showed more urogenital wiping than oil-treated animals in either side of the test cage. In a 2nd experiment, ferrets treated sequentially with TP, oil, and estradiol benzoate (EB) were given simultaneous access to sides of a test cage previously soiled by either a breeding female or male. Either EB or TP treatment of females and TP treatment of males facilitated the investigation of odors of opposite-sex ferrets. Females given TP and males given either TP or EB showed increased urogenital wiping in both sides of the test cage. Sex steroids modulate scent investigation and marking in adult ferrets in a sexually differentiated fashion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differences in the sexual conditioned behavior of male and female Japanese quail (Coturnix japonica).

The conditioned responses of male and female Japanese quail (Coturnix japonica) were compared in a Pavlovian conditioning procedure in which presentation of a brief conditioned stimulus was immediately followed by the release of a copulation partner. Male quail vigorously approached the conditioned stimulus and were much more likely to enter the compartment housing their copulation partner than were female birds (Experiment 1). In females, sexual conditioning resulted in increased squatting (Experiment 2). This response was the reflection of sexual behavior rather than more general social behavior (Experiment 3). These findings provide the first definitive evidence of sexual learning in female quail and are consistent with the interpretation that sexual conditioning increases sexual arousal or receptivity in both sexes but the increase has different behavioral manifestations in male and female quail. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contextual conditioning and the control of copulatory behavior by species-specific sign stimuli in male Japanese quail.

Three experiments were conducted to identify species-specific sign stimuli sufficient to elicit copulatory behavior in male Japanese quail and to determine how learning is involved in the control of behavior by these sign stimuli. In Exp 1, sexually experienced Ss were tested for copulatory behavior with a live female quail and with a model consisting of a female quail's head and neck mounted in front of a foam pad. Comparable levels of copulatory behavior were observed in the two tests, indicating that static visual cues provided by a female quail's head and neck are sufficient to elicit copulatory behavior in this species. Exp 2 showed that male birds that previously received numerous opportunities to copulate with a live female quail in the test situation were significantly more likely to copulate with the head?+?neck model than were sexually inexperienced Ss. Exp 3 showed that prior sexual experience with live quail facilitated responding to the head?+?neck model only if the sexual experience was provided in the same place where Ss were later tested with the model. This finding suggests that sexual experience facilitates control of copulatory behavior by species-specific sign stimuli through contextual conditioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of testosterone propionate administered perinatally on sexual behavior of female ferrets.

Conducted an experiment with 25 female and 8 male albino ferrets ( Mustela furo ). Females that received injections of testosterone propionate (TP) early in postnatal life displayed significantly more masculine behavior than did control females when gonadectomized and administered either TP or estradiol benzoate in adulthood. This increased masculine response potential was not correlated with the effects of early TP treatment on phallic development. In contrast to results obtained in most other species, perinatal administration of TP to females failed to disrupt their ability to display the behavior that is characteristic of the sexually receptive animal in estrus. When estrogenic stimulation was provided in adulthood, the receptive behavior of 3 groups of perinatally androgenized females was indistinguishable from that of both male and female controls. However, after gonadectomy and administration of TP, control males and females that had received TP prenatally plus on Day 3 were significantly more receptive than were control females. The induction of receptivity by TP was significantly inhibited by simultaneous administration of the antiestrogen MER-25. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sexual fetishism in a quail (Coturnix japonica) model system: Test of reproductive success.

In the present study, the authors explored the reproductive consequences of fetishistic behavior in a previously developed animal model of sexual fetishism (F. K?ksal et al., 2004). Male domesticated quail (Coturnix japonica) received sexual conditioning trials in which a terrycloth object (the conditioned stimulus [CS]) was paired with the opportunity to copulate with a female quail (the unconditioned stimulus). Approximately half of the male quail came to copulate with the CS object and were considered to have developed fetishistic behavior. Each of the male quail was then tested with a female quail, whose eggs were incubated to determine rates of fertilization. The CS object was present for 30 s before and during the copulation test. Fetishistic male quail were slower to achieve cloacal contact with the female quail and showed less efficient copulatory behavior. However, they fertilized a greater proportion of eggs than nonfetishistic male quail. These results are unexpected from previous studies of the relationship between reproductive success and copulatory behavior and are discussed in terms of how fetishistic behavior directed toward an inanimate object may modify male-female interactions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aromatase inhibition blocks the activation and sexual differentiation of appetitive male sexual behavior in Japanese quail

Two experiments investigated the role of estrogens in the activation and sexual differentiation of appetitive sexual behavior (ASB) in Japanese quail (Coturnix japonica) as measured by a learned social proximity response. Injection of the aromatase inhibitor R767 13 in castrated, testosterone (T)-treated male quail completely suppressed ASB, confirming that, like consummatory sexual behavior, ASB is mediated by T aromatization. ASB is not observed in female quail, even if they are treated with T as adults. The role of embryonic estrogens in the sexual differentiation of ASB was tested by blocking estrogen synthesis in ovo. Control male and T-treated female quail deprived of estrogens during embryonic life learned the social proximity response used to assess ASB, whereas control female quail did not, despite the presence of high T. Thus, ASB is demasculinized by the action of embryonic estrogens during ontogeny as is consummatory behavior.     

Determinants of social proximity in Japanese quail (Coturnix coturnix japonica): Male behavior.

Studied social proximity in 6 experiments, using a total of 64 Japanese quail. Following opportunity to copulate with a female housed in an adjacent compartment, males spent 64% of their time near a window that provided visual access to the female (Exp I). This social proximity behavior persisted for at least 2 wks of continual exposure to the window despite lack of further physical access to the female (Exp II) and was evident at all daylight hours (Exp III). Females stimulated more proximity behavior in male conspecifics than did other males or birds (e.g., yellow ducklings, parakeets) of other species (Exps IV and V). The females did not have to be previous sexual partners, familiar, sexually experienced, or reproductively competent to stimulate proximity behavior in males (Exps IV and V). Exp VI demonstrated that the social proximity behavior was primarily a response to the visual aspects of the females. Results are discussed in relation to mate-guarding and surveillance behavior, and implications of the data for sexual classical conditioning of male Japanese quail are noted. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Control of reproductive behavior by sex steroids in male quail.

Conducted 2 experiments on the ability of different sex steroids to stimulate crowing, strutting, and copulation. Exp I with 32 male Japanese quail was designed to maximize crowing. Intact untreated males and castrated males treated with 2 dosages of testosterone propionate (TP), with 2 dosages of dihydrotestosterone propionate (DHTP), or with oil were tested. The DHTP-treated males crowed extensively; TP-treated males crowed, but to a lesser extent than DHTP-treated males. In Exp II (30 Ss), which was designed to maximize strutting and copulation, males with photically regressed testes were treated with DHTP, DHTP?+?estradiol benzoate (EB), or EB alone and were tested with female partners. The DHTP-treated males did not copulate, but 2 birds strutted. The EB-treated males copulated but did not strut. Males receiving DHTP?+?EB strutted and copulated. These results suggest that (a) copulation in quail may involve conversion of testosterone to estrogen by the brain; (b) crowing and strutting may involve conversion of testosterone to dihydrotestosterone by the brain; and (c) in quail, the different components of male reproductive behavior show divergent patterns of hormone responsiveness, and thus the neural tissues underlying these behaviors have different molecular requirements for activation by steroids. (42 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Is sexual motivational state linked to dopamine release in the medial preoptic area?

The medial preoptic area (mPOA) is a key site for the dopaminergic enhancement of male sexual behavior. Dopamine release increases in the rat mPOA with mating, supporting the critical stimulatory role played by preoptic dopamine on male sexual behavior. However, it has been questioned whether dopamine is specifically related to the occurrence of male sexual behavior and not simply involved in general arousal. To address this question, we asked whether dopamine release in the mPOA is linked to the production of male sexual behavior in Japanese quail (Coturnix japonica), a species that exhibits a much shorter temporal pattern of copulation than rats and does not have an intromittent organ, resulting in a very different topography of their sexual response. Extracellular samples from the mPOA of adult sexually experienced male quail were collected every 6 min before, during, and after exposure to a female using in vivo microdialysis and analyzed using high-performance liquid chromatography with electrochemical detection. Extracellular dopamine significantly increased in the presence of a female and returned to baseline after removal of the female. However, quail that failed to copulate did not display this increased release. These findings indicate that it is not solely the presence of a female that drives dopamine release in males, but how a male responds to her. Furthermore, in quail that copulated, dopamine release did not change in samples collected during periods of no copulation. Together, these findings support the hypothesis that dopamine action in the mPOA is specifically linked to sexual motivation and not only to copulatory behavior or physical arousal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Methamphetamine impairs sexual motivation but not sexual performance in male Japanese quail.

The present study investigated the effects of chronic pre-exposure to methamphetamine on sexual motivation and performance in male Japanese quail. Quail were pre-exposed to methamphetamine (1.0 or 3.0 mg/kg ip) or saline (ip) once daily for 10 days and locomotor activity was measured. After a 10 day washout period, sexual motivation was measured in a straight-arm runway with visual access to a female at one end. Three to 5 hr after sexual motivation tests, males were allowed to copulate with a receptive female quail and copulatory behavior was assessed. Tests were conducted once per day for 10 days. Results showed that males pre-exposed to methamphetamine had decreased locomotor activity compared to saline controls. Males pre-exposed to METH later ran slower toward a female in the runway and spent less time near her. In contrast, methamphetamine pre-exposed males showed similar copulatory behavior as saline pre-exposed males. The findings suggest that chronic pre-exposure to methamphetamine may impair sexual motivation but not sexual performance. The findings are discussed from a comparative perspective and with regard to their clinical relevance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of novelty on the reproductive behavior of male Japanese quail (Coturnix coturnix japonica).

In Exp I, 8 sexually deprived male Japanese quail were exposed to 1 of 7 female Japanese quail until they satisfied a 20-min sexual satiation criterion. The female was then replaced with a novel female or was allowed to remain in the test cage undisturbed. Introduction of the novel female did not reinvigorate sexual behavior above levels observed when the female was allowed to remain undisturbed. In Exp II, with 9 males and 15 females, males that were not sexually deprived were tested in the presence of 2 females. During experimental tests, 1 of the females was novel and the other was familiar. During control tests, both of the females were familiar. The presence of a novel female increased overall levels of male sexual behavior and also increased the number of males engaged in reproductive behavior. However, the enhanced sexual behavior was not differentially directed toward the novel or familiar female. Implications of these findings for the mating system of Japanese quail and for studies of the role of novelty in sexual behavior are discussed. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Male-female differences and the influence of neonatal and adult testosterone on intraspecies aggression in rats.

Tested Sprague-Dawley male and female albino rats for intraspecies aggression without the use of shock. In the 1st experiment, 6 male pairs showed more biting attacks, offensive sideways movements, and self-grooming than did 6 female pairs; male pairs also showed more stereotyped defensive/submissive behaviors and were wounded more frequently. The 2nd experiment with 103 Ss examined the effects of neonatal castration and testosterone propionate (TP) on fighting. Males castrated at birth attacked other males less frequently than did controls when tested with TP treatment as adults. The TP given at birth to neonatally castrated males restored attacks to control levels. Females given TP as neonates did not differ from either male or female controls. Other aggressive/defensive behaviors, however, did not show this pattern. Results suggest that while the presence of testosterone during a brief postnatal period and during adulthood is necessary for attack behavior to occur, other related behaviors may not be affected in a similar manner. (11/2 p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hormonal basis of sexual differentiation in the Japanese quail.

On the 10th day of incubation, Japanese quail eggs (Coturnix coturnix japonica) either were injected with testosterone propionate (TP), estradiol benzoate (EB), or oil, or were not injected. When sexually mature, all Ss were examined for a variety of sexually dimorphic behavioral and physical characteristics, both masculine and feminine. They were then exposed to a short photoperiod (causing gonadal regression), treated with either TP or EB, and examined again. Either androgen or estrogen administered before hatching demasculinized males but did not masculinize females or defeminize either sex. In contrast, early sex hormones masculinize and/or defeminize mammals. This difference is discussed in relation to other differences in avian and mammalian sexuality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gonadal hormone activation of male courtship ultrasonic vocalizations and male copulatory behavior in castrated male deer mice (Peromyscus maniculatus bairdi).

Examined the influence of testosterone (T), a 5-alpha-reduced metabolite of T (dihydrotestosterone), and an aromatized metabolite of T (estradiol) on 35-kHz ultrasonic calling and copulatory behavior by 72 male deer mice. Daily treatment with T propionate (TP), dihydrotestosterone propionate (DHTP), or estradiol benzoate (EB) restored ultrasonic calling in long-term castrated Ss. Both TP and DHTP restored copulatory behavior, but EB was ineffective. Synergism of EB and DHTP action was observed; when subthreshold doses of EB (1 μg/day) and DHTP (50 μg/day) were administered in combination, ultrasonic calling and copulatory behavior were activated. In relation to other comparative findings, results indicate that the degree to which male sexual behavior is facilitated by 5-alpha-reduced androgens and/or estrogens is influenced by the species and the particular pattern of masculine behavior under consideration. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differential effects of beta-endorphin and Met- and Leu-enkephalin on steroid hormone-induced lordosis in ovariectomized female rats

The effect of intrathirdventricular (I.T.V.) injections of beta-endorphin, anti-beta-endorphin antiserum, Met-enkephalin, Leu-enkephalin, and naloxone on the initial activation and final development of steroid hormone-mediated induction of female sexual receptivity was studied in ovariectomized female rats. The lordosis response to male mounts in ovariectomized rats after subcutaneous (S.C.) estradiol benzoate (EB) and progesterone (Prog) priming was facilitated by beta-endorphin, and Met-enkephalin (10 microg x 5 microl(-1)), but inhibited by Leu-enkephalin, when the peptides were injected into the third ventricle at the time of S.C. EB priming. A lower dose Met-enkephalin had no effects. Lordosis behavior in steroid hormone-primed rats was significantly facilitated when I.T.V. injections of Met-enkephalin were given 1 h prior to behavioral testing (47 h after EB priming). At 1 h prior to behavioral testing (47 h after EB priming), I.T.V. injection of beta-endorphin significantly inhibited lordosis behavior, especially at the higher dose of beta-endorphin (10 microg x 5 microl(-1)). Under those conditions, Leu-enkephalin had no effect. Lordosis behavior of ovariectomized female rats receiving S.C. steroid hormones and I.T.V. injection of anti-beta-endorphin antiserum was significantly inhibited when anti-beta-endorphin antiserum was injected at the time of EB priming. However, lordosis was significantly facilitated when anti-beta-endorphin antiserum was injected 1 h prior to the behavior testing (47 h after EB priming). In contrast, I.T.V. injection of the opioid antagonist naloxone given either at the time of EB priming or 1 h prior to behavioral testing (47 h after EB priming) decreased lordosis behavior. The present results suggest that 1) beta-endorphin, Met-enkephalin, and Leu-enkephalin have differential effects in the control of lordosis behavior; 2) the opioidergic systems may modulate initial-stage and final-stage estrogen-induced lordosis behavior; and 3) the opioidergic systems could be divided into the endorphinergic modulation-type and enkephalinergic modulation-type, based on their effects on lordosis behavior.     

A New Model for Sexual Conditioning: The Ring Dove (Streptopelia risoria).

Sexual conditioning investigations have primarily used rats and domestic quail as subjects. Although much has been learned from such experiments, the relative simplicity of rat and quail reproductive behavior prohibits investigation of certain experimental questions about sexual conditioning. In contrast, the reproductive behavior of male and female ring doves (Streptopelia risoria) is complex, involving courtship, bonding, and parental care. In the present experiment, male ring doves that were presented with a visual conditioned stimulus paired with access to their pair-bonded mate (the unconditioned stimulus) showed sexual conditioned responding in the presence of the conditioned stimulus. These results represent the first evidence of sexual conditioning in ring doves and illustrate the potential of ring doves as a useful model for future sexual conditioning investigations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dopamine release in the medial preoptic area is related to hormonal action and sexual motivation.

To help elucidate how general the role of dopamine (DA) release in the medial preoptic area (mPOA) is for the activation of male sexual behavior in vertebrates, we recently developed an in vivo microdialysis procedure in the mPOA of Japanese quail. Using these techniques in the present experiment, the temporal pattern of DA release in relation to the precopulatory exposure to a female and to the expression of both appetitive and consummatory aspects of male sexual behavior was investigated. Extracellular samples from the mPOA of adult sexually experienced male quail were collected every 6 min before, while viewing, while in physical contact with, and after exposure to a female. In the absence of a precopulatory rise in DA, males failed to copulate when the barrier separating them from the female was removed. In contrast, males that showed a substantial increase in mPOA DA during precopulatory interactions behind the barrier, copulated with females after its removal. However, there was no difference in DA during periods when the quail were copulating as compared to when the female was present but the males were not copulating. In addition, we show that precopulatory DA predicts future DA levels and copulatory behavior frequency. Furthermore, the size of the cloacal gland, an accurate indicator of testosterone action, is positively correlated with precopulatory DA. Taken together, these results provide further support for the hypothesis that DA action in the mPOA is specifically linked to sexual motivation as compared to copulatory behavior per se. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sexual dimorphism in the social proximity behavior of Japanese quail (Coturnix coturnix japonica).

Previous research by the present authors (see record 1986-16367-001) showed that after opportunity for copulation, male Japanese quail spent about 75% of their time throughout daylight hours near a window that provided visual access to a female conspecific. In Exp I of the present study, 8 female Japanese quail typically spent less than 20% of their time near a window that provided visual access to 1 of 8 male conspecifics under comparable conditions. In Exp II, using the same Ss, a small clear plastic cage was placed in a large test arena, and Ss were observed when the cage was either empty or contained a sexual partner. Males tended to remain much closer to the cage when it contained a female conspecific than when it was empty. In contrast, the presence of a male did not significantly attract females to the cage area. These findings demonstrate strong sexual dimorphism in the social proximity behavior of Japanese quail. Results are discussed in terms of implications concerning the social structure of Japanese quail and implications for studies of sexual classical conditioning. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)