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)     

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)     

Effects of enclosure size on sexual behavior of Japanese quail (Coturnix japonica).

The authors determined whether results of experiments on copulatory and affiliative behavior of pairs of Japanese quail (Coturnix japonica) conducted in a closely confining apparatus would predict behavior in a large enclosure in which female quail could avoid contact with male quail. As found previously in studies of closely confined quail, in a large enclosure containing numerous barriers, both unmated female quail and mated female quail laying unfertilized eggs were more likely to remain near a confined male quail than were mated female quail laying fertilized eggs. Furthermore, the number of copulations that a pair engaged in when closely confined predicted the number of copulations that they engaged in when they were in the large enclosure. Patterns of affiliation and of mating in a confining laboratory apparatus thus predicted behavior in a larger enclosure that provided female quail with opportunity to avoid contact with male 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)     

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)     

MPOA lesions affect female pacing of copulation in rats.

This study examined the effects of electrolytic and ibotenic acid (IA) lesions of the medial preoptic area (MPOA) on the temporal pattern of female sexual behavior in the laboratory rat. Both electrolytic and IA MPOA lesions significantly increased the female's latency to return to the male after an intromission or an ejaculation, thereby decreasing the percentage of time spent with a male. Both types of MPOA lesions significantly increased the percentage of times the female left the male's chamber following intromissions. These results demonstrate that neurons in the MPOA regulate the female's temporal copulatory behavior, and the authors suggest that they do so by virtue of their response to vaginocervical stimulation. Studies of female pacing draw attention to parallels between male and female sexual behaviors, including the possibility that they are regulated by similar neural substrates in the MPOA. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The foam production system of the male Japanese quail: characterization of structure and function

The research described here characterizes a unique neuromuscular system involved in reproductive behavior--the foam production system of the male Japanese quail (Coturnix japonica). Male quail produce a large amount of foam that is transferred to the female during copulation, enhancing male fertilization success. The source is the foam gland complex, a large sexually dimorphic, androgen sensitive, external protuberance of the dorsal cloaca, consisting of glandular units interdigitated with striated muscle fibers of the sphincter cloacae muscle (mSC). Electromyographic (EMG) analysis of mSC activity in freely moving males interacting with females revealed different characteristics of the EMG signal during copulation, voiding of excreta, and other mSC movement. The amount of mSC activity and also the amount of foam produced were greatly increased by the presence of a female behind a screen. Denervation of mSC eliminated normal mSC movement and also abolished foam production, confirming that mSC activity is the mechanism for foam production. The spinal cord locations of the motoneurons innervating the major cloacal muscles, including mSC, were determined by injecting cholera-toxin conjugated horseradish peroxidase into each muscle. Labelled somata with multiple primary dendrites were located in Area IX of the lateral motor column of synsacral segments 7, 8, or 9 or 8, 9, and 10. The motoneurons serving mSC were intermingled with those projecting to the other cloacal muscles, but there were differences in the rostralcaudal placement of these neural populations. Thus mSC activity is an integral part of the male's reproductive behavior, mSC activity can be socially stimulated, and mSC activity occurring in anticipation of copulation is likely to be functionally significant. Continued investigation of this highly accessible system has the potential to shed light on the mechanisms by which complex motor acts are produced and hormonally regulated.     

Stimulus control of copulatory behavior in sexually naive male Japanese quail (Coturnix japonica): Effects of test context and stimulus movement.

Sexually experienced male quail (Coturnix japonica) are more likely to engage in copulatory behavior than sexually naive ones. These experiments suggest that sexual experience in a particular place may facilitate later copulatory responding because of increased familiarity with the contextual cues of the environment. Male quail in Exp 1 did not copulate reliably with taxidermic models of females in a novel context, even though some of the subjects were allowed to copulate with female quail in their home cages. In contrast, sexually naive males in Exps 2 and 3 copulated vigorously with taxidermic models of females in a familiar context. In Exp 4, sexually naive males tested in an unfamiliar context were more likely to copulate with a moving than with a static model. The stimulus control of copulatory behavior in sexually naive male quail was similar to that in sexually experienced ones but only in familiar contexts. (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)     

Hormonal control of behavior in the Japanese quail.

Adult male and female Japanese quail were functionally castrated by exposure to a short photoperiod and then injected with either estradiole benzoate (EB) or testosterone propionate (TP). Females injected with EB (n = 24) exhibited normal sexual receptivity again but displayed no male courtship behavior. Males injected with EB (n = 10) showed both male and female copulatory patterns. Females injected with TP (n = 14) showed little sexual behavior of any sort, while males injected with TP (n = 10) displayed male sexual behavior. The male quail is thus more bisexual than the female. In contrast with mammalian species, the female is more bisexual. The difference is discussed in relation to the differences in the embryology and cytogenetics of birds and mammals. (29 ref.) (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.     

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 ultrasonic vocalizations and male's urine on female rat readiness to mate.

Solitary estrous female Long-Evans rats were presented with ultrasonic vocalizations and/or urine of males to determine their effects on the females' subsequent copulatory behavior. Following exposure to ultrasounds, females exhibited a shorter latency to dart and a higher rate of darting when a male was presented. The vocalization effect was enhanced when male urine was present, but urine alone had no effect. The rate of copulation was also increased by the vocalization priming of the female. For a few individual females, ultrasounds elicited darting in the absence of a male. Results indicate that auditory cues, particularly in association with appropriate olfactory cues, prime estrous females for proceptive behavior. This increases both the likelihood and the rate of sexual performance and, therefore, the probability of successful mating. (17 ref) (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)     

Hippocampal and cortical activity during sexual behavior in the female rat.

Studied hippocampal and cortical activity during sexual behavior in 6 female albino van Leeuwenhoek-Huis R-strain rats. Hippocampal theta appeared during S's soliciting behavior. High-frequency theta accompanying the male's pursuit slowed when the male mounted the female and then increased in frequency during the brief continuation of lordosis following mounts without vaginal penetration. During prolonged lordosis after intromissions and ejaculations, slow theta continued. No changes in cortical frequencies were observed during mounts, intromissions, or ejaculations. During immobility (standing, sitting, and lying down), hippocampal activity became slow and irregular. High-amplitude hippocampal and, eventually, cortical spindles developed during immobility as sexual exhaustion was approached. Immobility and its accompanying EEG spindling are interpreted as indicative of a sexual satiety or inhibitory process. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Consequences of perinatal hormone manipulation on the adult sexual behavior of female rats.

Compared male and female behavior of 46 female Sprague-Dawley albino rats treated with prenatal or prolonged postnatal testosterone propionate (TP) or cyproterone acetate (Cyp A), an antiandrogen, to 13 control females. Prenatal TP decreased quality and rate of lordotic responding while increasing incomplete and complete male copulatory rate. Postnatal TP also impaired female behavior but increased only complete male copulations. Results suggest that, in the rat, gonadal steroid levels present during prenatal as well as postnatal developmental stages determine the direction and degree of differentiation of adult sexual behavior. Prenatal Cyp A had no effect on female behavior or external genitalia but decreased both types of male copulatory responses, suggesting that male behavior in normal females is based on prenatal androgenic modification of the nervous system. (30 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus control of copulatory behavior in male Japanese quail

The copulatory behavior of sexually experienced male Japanese quail was tested using taxidermic models with varying proportions of natural and artificial features. Completely artificial models exerted little control over copulatory behavior, and whole natural body models reliably elicited copulatory behavior. In single model presentation tests, a model containing a natural head and neck with an artificial body was as effective in eliciting copulatory behavior as a whole body model, but a model containing a natural body with an artificial head and neck was largely ineffective. In choice tests, however, males clearly preferred a whole model over a natural head and neck model, and a natural body model over a completely artificial model. These data indicate male Japanese quail do attend to features of body plumage. Furthermore, test procedures can influence conclusions about effective controlling stimuli.     

Precontact 50-kHz vocalizations in male rats during acquisition of sexual experience.

50-kHz ultrasonic vocalizations emitted by male rats during a 5-min period before introduction of a female (precontact vocalizations [PVs]) were analyzed in the context of acquisition of sexual experience. Changes in the main copulatory parameters and their N-methyl-D-aspartate (NMDA) receptor dependence, the role of contact with either anestrous or estrous females, and conditioning to odor and background cues were also investigated. Mount latency (ML) and intromission latency (IL) decreased after the 1st copulatory session, but ejaculation latency (EL) changed significantly only starting from the 4th session onward. The number of PVs gradually increased during the first 3–4 sessions. Blocking of NMDA receptors affected PVs and EL but not ML or IL. After a 5-month break in copulatory sessions, ML remained unchanged, whereas EL increased and the number of PVs decreased significantly. PVs were most robustly elevated by contact with estrous females. Exposure to background cues resulted in a linear decrease in number of PVs during 10 subsequent sessions without exposure to a female. The results suggest that, in the course of acquisition of a sexual experience, PVs reflect a learning process that depends on a rewarding value of sociosexual contact. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

6-Hydroxydopamine Lesions in Female Hamsters (Mesocricetus auratus) Abolish the Sensitized Effects of Sexual Experience on Copulatory Interactions With Males.

This study examined the effects of sexual experience in female hamsters (Mesocricetus auratus) on copulatory interactions with male hamsters. Female sexual experience improved the copulatory efficiency of sexually naive males, an effect that persisted for at least 6 weeks without further sexual behavior testing. In a 2nd study, dopamine lesions made in the region of the nucleus accumbens prior to sexual experience specifically blocked the effects of the female's sexual experience on the hit rate of naive males. These results suggest that sexual experience in female hamsters increases the efficiency of copulatory interactions with males, that these effects persist in the absence of further sexual experience, and that dopamine neurotransmission in the basal forebrain underlies this effect of sexual experience. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Activation of c-Jun NH2-terminal kinase (JNK/SAPK) in LLC-PK1 cells by cadmium

A male rat put in an open-field arena in which it is free to spend time in the vicinity of--but not in contact with--an estrous female, or in the vicinity of a male, usually spends more time with the female than with the male or elsewhere. Tentatively, the percentage of time spent in the vicinity of the female in this paradigm may be regarded as a measure of sexual motivation. In humans, treatment with selective serotonin reuptake inhibitors (SSRIs) may cause reduced libido. To investigate to what extent serotonin reuptake inhibition influences sexual motivation also in rats, we have tested the effect of subchronic treatment with fluoxetine on the behavior in the sexual motivation test described above; in addition, the effect of fluoxetine on male copulatory behavior was studied. Fluoxetine significantly reduced sexual motivation at subchronic but not at acute administration; moreover, fluoxetine-treated rats displayed an increased ejaculation latency. It is concluded that humans and rats respond similarly to the SSRI fluoxetine with respect to various aspects of sexual behavior.