Appetitive as well as consummatory aspects of male sexual behavior in quail are activated by androgens and estrogens.

Appetitive male sexual behavior was measured in male quail with the use of a learned social proximity procedure that quantified the time spent by a male in front of a window providing a view of a female that was subsequently released into the cage, providing an opportunity for copulation. The learned response is not acquired by castrated males but can be acquired when castrates are treated with testosterone (T) or with the synthetic estrogen diethylstilbestrol or with the endogenous estrogen 17β-estradiol. Only birds that become sexually active acquire the response. Conversely, birds in which the consummatory copulatory behavior is disrupted by treatment with the antiestrogen tamoxifen lose the anticipatory response. These results demonstrate that appetitive sexual behavior is, like copulation, activated by T and by estrogens. This suggests that intracerebral aromatization of T also plays a critical role in the activation of this behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intermanual differences on motor and psychomotor tests in alcoholics: no evidence for selective right-hemisphere dysfunction

The effects of pharmacological manipulations of dopaminergic transmission on appetitive and consummatory aspects of male sexual behavior were investigated in castrated male Japanese quail treated with exogenous testosterone. Appetitive male sexual behavior was assessed by measuring a learned social proximity response and consummatory behavior was assessed by measuring copulatory behavior per se. The nonselective dopamine receptor agonist, apomorphine, inhibited in a dose-dependent manner both components of male sexual behavior. Two indirect dopamine agonists were also tested. Nomifensine, a dopamine re-uptake inhibitor, decreased appetitive sexual behavior but increased the frequency of mount attempts, a measure of consummatory sexual behavior. Amfonelic acid, a compound that enhances dopaminergic tone by a complex mechanism, increased aspects of both appetitive and consummatory behaviors. These data suggest that, in quail, as in rodents, increases in dopaminergic tone facilitate both appetitive and consummatory aspects of male sexual behavior. Apomorphine may be inhibitory in quail because it acts primarily on D2-like receptors, unlike in rats, where it stimulates sexual behavior and acts primarily on D1-like receptors at low doses but interacts with D2-like receptors at higher doses. This is supported by the observation that stereotyped pecking, a behavior stimulated selectively in quail by D2 agonists, was increased by apomorphine but not by the two indirect agonists. The observed partial dissociation between the effects of these dopaminergic agonists on appetitive and consummatory sexual behaviors suggests that these two components of male sexual behavior may be controlled by the action of dopamine through different neuronal systems.     

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)     

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)     

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)     

Dietary phytoestrogens dampen female sexual behavior in mice with a disrupted aromatase enzyme gene.

Aromatization of testosterone (T) to estradiol (E2) during perinatal development in male rodents plays a significant role in sexual differentiation of the brain and adult behaviors. Exposure to estrogens during development can enhance masculine behaviors in adult females and reduce expression of female-typical behaviors in adult males. Previous studies have shown that, in addition to naturally occurring estrogens, dietary phytoestrogens can affect sexual differentiation. To distinguish between the effects of endogenous T-derived E2 and exogenous phytoestrogens, the authors used an aromatase knockout (ArKO) mouse that cannot produce E2 but is responsive to E2 via estrogen receptors α and β. Dams and their litters were maintained either on a standard mouse chow that was rich in phytoestrogens or on a chow nearly devoid of phytoestrogens. Mice were maintained on their perinatal diets after weaning. Adults of both sexes were gonadectomized and tested for lordosis behavior. In the ArKO females raised on a diet high in phytoestrogens, lordosis was reduced in comparison with females of both genotypes on the low phytoestrogen diet. The authors' findings suggest that dietary phytoestrogen consumption may partially defeminize adult female sexual behavior in the mouse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Brain sexual differentiation and gonadotropins secretion in the rat

1. The present work deals with sexual differences in gonadotropin regulation in the rat and the role of sexual organization of the hypothalamus in determining such differences. 2. Sex differences between male and female rats, with regard to their control of gonadotropin secretion, go beyond whether or not gonadotropins are released cyclically. Rats show additional sex differences (a) in the response of gonadotropins to removal and imposition of negative feedback signals and (b) in the ontogeny of gonadotropin regulation from birth to puberty. 3. There is a sensitive developmental period during which sexual differentiation of neural substrates proceeds irreversibly under the influence of gonadal hormones. In the rat this period starts a few days before birth and ends approximately 10 days after birth. Female rats treated during this sensitive period with androgens or estrogens will permanently lose the capacity to release GnRH in response to estrogenic stimulation. 4. Nevertheless although sexual differentiation is dramatically affected by events during the neonatal period, recent data question the "critical" nature of this period, as it has been shown that testosterone can still act on neural substrates well beyond (15 to 30 days of age) the neonatal period to defeminize and masculinize endocrine and behavioral functions. 5. Furthermore, the capacity for the normal display of female sexual behavior and for the cyclic release of gonadotropins is not, as has been assumed, inherent to central nervous tissue but depends on active hormonal estrogenic induction during a sensitive period of development. 6. Besides, during differentiation of male sexual brain function estrogens may be supportive, rather than directive, to the primary action of androgens. 7. Serotonergic, noradrenergic, and opioid systems participate in the sexual dimorphism in gonadotropin control in adult rats. 8. The sex difference in the postcastration LH rise is dependent on the early sexual organization of the hypothalamus, even though in adulthood it can also be influenced by a variety of factors such as the stage of the estrous cycle, age of the animal, estradiol pretreatment, and history of release from feedback inhibition. 9. The characteristic pattern of gonadotropin secretion in the female infantile rat, which is sexually differentiated, can be related to an increase in hypophyseal receptors coupled to an increase in the intracellular calcium response to GnRH. Such events depend on the sexual organization of the hypothalamus. In males the greater sensitivity to GnRH at 30 days is reflected in an increase in pituitary GnRH receptors but not in an increase in the magnitude of Ca2+ mobilization induced by GnRH, therefore it is probable that in this situation alternative second messengers may modulate high sensitivity. Neonatal androgenization of the hypothalamus may decrease the hypophyseal response to GnRH by an alteration in receptor concentration and signal transduction during the infantile period. 10. Finally, serotonergic, dopaminergic, opioid, and noradrenergic regulation of GnRH varies with increasing age, and the sexual organization of the hypothalamus by testosterone or estrogens is a determinant in such regulation.     

Social and sexual motivation in the mouse.

Does a sexual encounter have reward value for a learned operant response? Ovariectomized female mice with or without estradiol replacement were trained to perform a bar-contact operant response for either male or female targets. Response rates of females with estradiol replacement did not differ from those of females without estradiol replacement or females responding for access to females. Reflexive receptive sexual behavior remained responsive to estradiol replacement. Experiment 2 demonstrated that socially isolated females would respond faster for access to a female target than when group housed. Finally, the oxytocin blocker, atosiban, reduced both operant and reflexive social behavior. These results converge on the conclusion that the operant reward value of social and sexual contact is primarily social. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Systemic and intracerebroventricular injections of vasotocin inhibit appetitive and consummatory components of male sexual behavior in Japanese quail.

The authors investigated the behavioral actions of vasotocin (VT) in castrated testosterone-treated male Japanese quail. The appetitive and consummatory components of sexual behavior as well as the occurrence frequency of crows were inhibited, in a dose-dependent manner, by injections of VT. The authors observed opposite effects after injection of the V1 receptor antagonist, dPTyr(Me)AVP. Lower doses of VT were more active after central than after systemic injection, and effects of systemic injections of VT were blocked by a central injection of dPTyr(Me)AVP. The behavioral inhibition was associated with a modified diuresis after systemic but not central injection. These results provide direct evidence that VT affects male sexual behavior in quail by a direct action on the brain independent of its peripheral action on diuresis. (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)     

Effects of neurochemical lesions of the preoptic area on male sexual behavior in the Japanese quail

Two experiments were carried out during which the noradrenergic neurotoxin, 5-amino-2,4-dihydroxy-alpha-methylphenylethylamine (5-ADMP) was applied to the brain of quail in order to evaluate the role of the noradrenergic system in the control of male copulatory behavior. In the first experiment, the ICV injection of 5-ADMP slightly enhanced the sexual behavior observed in testosterone (T)-treated castrated male quail. This brings additional support to the notion that norepinephrine tonically inhibits male copulatory behavior in quail. In the second experiment, 5-ADMP implanted directly into the preoptic area disrupted the restoration by T of copulatory behavior in castrated quail and, at the same time, produced a brain lesion that partly destroyed the sexually dimorphic medial preoptic nucleus, a previously established site of T action on behavior. These lesions produced by a high (presumably too high) concentration of neurotoxin provided an independent confirmation of effects previously observed after electrolytic lesions. Correlation analyses also confirmed that the medial part of the POM just rostral to the anterior commissure is more closely associated with copulatory behavior and may, therefore, represent a key center for steroid action on this behavior.     

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)     

Photoperiodic and endocrine control of social proximity behavior in male Japanese quail (Coturnix coturnix japonica).

Experiment 1 demonstrated that the social proximity behavior of male Japanese quail declines significantly when photostimulation is restricted to 2 hr daily, but can be restored by reinstituting the normal schedule. Changes in the photoperiod produced corresponding changes in the size of the cloacal gland, an androgen-dependent organ. The low levels of social proximity behavior and cloacal gland size of males maintained on short daily exposures to light also could be reversed by sc implants of testosterone (Experiment 2), and this recovery was to some extent sensitive to testosterone dose (Experiment 3). The present studies indicate that social proximity behavior in male Japanese quail is androgen dependent and provide a behavioral assay for neurohormonal studies of sexual behavior that does not depend on brief phasic responses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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)     

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)     

Potential pathogenic mechanisms of periodontitis associated pregnancy complications

The authors investigated the behavioral actions of vasotocin (VT) in castrated testosterone-treated male Japanese quail. The appetitive and consummatory components of sexual behavior as well as the occurrence frequency of crows were inhibited, in a dose-dependent manner, by injections of VT. The authors observed opposite effects after injection of the V1 receptor antagonist, dPTyr(Me)AVP. Lower doses of VT were more active after central than after systemic injection, and effects of systemic injections of VT were blocked by a central injection of dPTyr(Me)AVP. The behavioral inhibition was associated with a modified diuresis after systemic but not central injection. These results provide direct evidence that VT affects male sexual behavior in quail by a direct action on the brain independent of its peripheral action on diuresis.     

Do sex differences in the brain explain sex differences in the hormonal induction of reproductive behavior? What 25 years of research on the Japanese quail tells us

Early workers interested in the mechanisms mediating sex differences in morphology and behavior assumed that differences in behavior that are commonly observed between males and females result from the sex specificity of androgens and estrogens. Androgens were thought to facilitate male-typical traits, and estrogens were thought to facilitate female-typical traits. By the mid-20th century, however, it was apparent that administering androgens to females or estrogens to males was not always effective in sex-reversing behavior and that in some cases a "female" hormone such as an estrogen could produce male-typical behavior and an androgen could induce female-typical behavior. These conceptual difficulties were resolved to a large extent by the seminal paper of C. H. Phoenix, R. W. Goy, A. A. Gerall, and W. C. Young in (1959, Endocrinology 65, 369-382) that illustrated that several aspects of sexual behavior are different between males and females because the sexes have been exposed during their perinatal life to a different endocrine milieu that has irreversibly modified their response to steroids in adulthood. Phoenix et al. (1959) therefore formalized a clear dichotomy between the organizational and activational effects of sex steroid hormones. Since this paper, a substantial amount of research has been carried out in an attempt to identify the aspects of brain morphology or neurochemistry that differentiate under the embryonic/neonatal effects of steroids and are responsible for the different behavioral response of males and females to the activation by steroids in adulthood. During the past 25 years, research in behavioral neuroendocrinology has identified many sex differences in brain morphology or neurochemistry; however many of these sex differences disappear when male and female subjects are placed in similar endocrine conditions (e.g., are gonadectomized and treated with the same amount of steroids) so that these differences appear to be of an activational nature and cannot therefore explain sex differences in behavior that are still present in gonadectomized steroid-treated adults. This research has also revealed many aspects of brain morphology and chemistry that are markedly affected by steroids in adulthood and are thought to mediate the activation of behavior at the central level. It has been explicitly, or in some cases, implicitly assumed that the sexual differentiation of brain and behavior driven by early exposure to steroids concerns primarily those neuroanatomical/neurochemical characteristics that are altered by steroids in adulthood and presumably mediate the activation of behavior. Extensive efforts to identify these sexually differentiated brain characteristics over the past 20 years has only met with limited success, however. As regards reproductive behavior, in all model species that have been studied it is still impossible to identify satisfactorily brain characteristics that differentiate under early steroid action and explain the sex differences in behavioral activating effects of steroids. This problem is illustrated by research conducted on Japanese quail (Coturnix japonica), an avian model system that displays prominent sex differences in the sexual behavioral response to testosterone, and in which the endocrine mechanisms that control sexual differentiation of behavior have been clearly identified so that subjects with a fully sex-reversed behavioral phenotype can be easily produced. In this species, studies of sex differences in the neural substrate mediating the action of steroids in the brain, including the activity of the enzymes that metabolize steroids such as aromatase and the distribution of steroid hormone receptors as well as related neurotransmitter systems, did not result in a satisfactory explanation of sex differences in the behavioral effectiveness of testosterone. Possible explanations for the relative failure to identify the organized brain characteristics responsible for behavio     

A comparative approach to the study of dopamine and male sexual behavior: What can Japanese quail teach us? A reply to Pfaus (2010).

One of the most robust findings about dopamine (DA) is that the stimulation of dopaminergic systems promotes the activation of male sexual behavior. The commentary by Pfaus (see record 2010-24688-009) included a thorough review of studies of DA and male sexual behavior. We agree with him that the release of DA in the preoptic region in male quail in response to females and in association with the exhibition of male sexual behavior appears to be highly conserved and that it seems to have evolved very early in the evolutionary history of the vertebrate brain. However, additional data have been collected indicating that there may be significant species differences in the dopaminergic regulation of male behavior in quail compared with rats. In this response, we take the opportunity to make a few broader points about DA and male sexual behavior in light of other studies that have been conducted in birds and introduce some interesting taxonomic variation that is still not well understood. (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)     

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)