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Changes in the animals' environment often impact on their behavior and the way they communicate. Particularly in spiders, living on webs or not is a determining factor. While the Lycosidae family predominantly comprises wandering spiders, only a few species inhabit webs. Aglaoctenus oblongus (C.L. Koch 1847) challenges this norm, as it has been found both in webs and wandering, suggesting a previously undocumented mixed strategy. This study aims to: (1) describe the sexual behavior of A. oblongus under laboratory conditions and (2) utilize phenological data to elucidate when and where mating occurs. Sexual encounters were observed within and outside webs, with minimal differences noted between them. Courtship was characterized by groping and leg shaking performed by the males. Copulation was lengthy (near to seven hours), featuring an irregular pattern of palpal insertions, and culminating in a backward dismount. Individuals showed a mixed life history, with the spiders most often found in webs being females with eggs. Both sexes were found throughout the year, with a peak in autumn. We compare the sexual characteristics of this species with that of A. lagotis (also belonging to the Sosippinae subfamily), the only other wolf spider studied to date that exclusively inhabits webs. [ABSTRACT FROM AUTHOR]

Background: GnRH agonists have been used to halt the development of puberty in children with precocious puberty since the 1980s. Recently, drugs like Lupron Depot® (leuprolide acetate), have been used to suppress pubertal progression in adolescents who are questioning their gender identity. However, few preclinical studies have been conducted to investigate potential effects of using GnRH agonists in this context. Methods: The present study tested the effects of daily leuprolide treatment (50 µg/kg, postnatal day (PD) 25–50) on pubertal onset in female (i.e., vaginal opening) and male (i.e., preputial separation) Long-Evans rats. The first estrous cycle immediately after vaginal opening was also measured. Sexual behavior and sexual motivation were tested using the partner-preference paradigm. Female rats were tested during the first behavioral estrus after treatment ended (between PD 51–64). Male rats were tested weekly for four consecutive weeks starting three days after treatment ended (PD 53). Results: Consistent with previous findings, leuprolide significantly delayed pubertal onset in both female and male rats. In addition, the first estrous cycle during the treatment period was disrupted by leuprolide, as indicated by a failure to cycle into estrus after vaginal opening until treatment ended. However, leuprolide affected neither sexual motivation nor fertility when female rats were tested within 14 days of leuprolide treatment ending. In contrast, the development of copulatory behavior and sexual motivation was significantly delayed by leuprolide in male rats; however, mature reproductive behavior was observed by the fourth week post-treatment. Conclusions: Taken together with previous findings, the present results indicate that male rats may be more sensitive to periadolescent leuprolide administration, taking longer to overcome the effects of leuprolide than female rats. Nevertheless, not long after leuprolide treatment is discontinued, sex-typical reproductive physiology and behavior emerge fully in female and male rats, indicating that the drug's effects are not permanent. If translatable to humans, leuprolide may be a reversible option to give adolescents more time to consider their gender identity with minimal long-term effects on sexual development. Highlights: Leuprolide acetate (50 µg/kg, postnatal day 25–50) suppresses pubertal development in female and male rats. Estrous cyclicity is suppressed during treatment in female rats. Development of male copulatory behavior and sexual motivation is significantly delayed but reaches control levels within a month of treatment termination. Female sexual motivation and fertility are unaffected by leuprolide once treatment ends. [ABSTRACT FROM AUTHOR]

In spite of hermaphroditism, most earthworm species reproduce by cross fertilization i.e. by the process of copulation of two mature partners. Mechanism of copulation in few earthworm species (Lumbricus terrestris) is known. However literature on neurosecretory control of copulation in earthworm is lacking. In the present study 30 pairs of conjugating earthworms of Eisenia fetida were collected from laboratory culture beds during 2016 of monsoon season. Cerebral and ventral ganglia of 10 pairs of conjugating earthworms and 20 pairs of post conjugation (2 hrs after separation, 4 hrs after separation) earthworms were fixed in Bouin’s fluid for cytomorphological studies on their cerebral neurosecretory cells. Earthworms (10 numbers) debrained through anterior transection of first five segments (brain present in 3rd segment) by sterilized paragon knife were studied to observe conjugation if any. Cerebral and ventral ganglia of 5 pairs of pre-conjugating earthworms were considered as control. Cerebral and ventral ganglia of earthworms displayed chiefly two types of neurosecretory cells such as A cells and B cells. The A cells are deeply stained AF-positive cells arranged in upper cortical tier beneath the perineurium and generally exhibiting process of axonal transport. The B cells, generally larger in size than A cells, are lightly or moderately stained with or without axonal transport and lie in between cortical A cells and central fibrous neuropile. In the cerebral ganglia the A cells outnumbered the B cells, while in the ventral ganglia the opposite is true. Debrained E. fetida survived but did not conjugate. Secretory dynamics in the cerebral and ventral ganglionic neurosecretory cells A and B were recorded in pre-conjugating, conjugating and post-conjugating earthworms. Absence of conjugation in debrained worms and exhibition of the same in earthworms with brain and its changes in neurosecretory profile clearly indicate involvement of cerebral neurosecretion in the phenomenon of conjugation in earthworm. Our result indicates probable involvement of cerebral neurohormone in the process of conjugation in E. fetida. DOI: http://dx.doi.org/10.5281/zenodo.3948600

Africa hosts a high number of bat species, many of which have been poorly studied. Among African vesper bats (Vespertilionidae), some species are morphologically similar to each other, hampering identification in the field. Consequently, basic information on these species' population dynamics, distributions, or behaviors is vague and/or incorrectly documented. Among some Vespertilionidae, variation in flaccid penis shape enables species identification. This variation in morphology is thought to have resulted from sexual selection operating on the erect penis. Furthermore, in the context of strong postcopulatory competition, divergence in sperm traits may have evolved among closely related species. These male reproductive characters have hitherto not been investigated in southern African vespertilionid bats. In this study, we present the morphology of flaccid penis, erect penis, and sperm, of six small vesper species, based on the prediction that these characters have evolved sufficiently toward different optima to allow species discrimination. Species identification based solely on the morphological characters of the penis entirely matched species identification based on traditional (craniodental) characters. We illustrate penis morphology of these species to assist with field identifications for future ecological, conservation, or behavioral studies. Sperm morphology was sufficient to discriminate between the different genera, but could not reliably separate Neoromicia nana , Ne. zuluensis , and Ne. capensis. Hence, we demonstrate that these difficult to identify species can be readily distinguished based on traits directly observable in the field and on living animals, which will lead to more focused field studies on these otherwise morphologically cryptic species. Finally, our comparisons of penis morphology support the suggestion that Hypsugo anchietae is better placed within the genus Neoromicia. [ABSTRACT FROM AUTHOR]

Nurse sharks are vulnerable of extinction in Brazil. Although its reproductive behavioral repertoire is already known, including indications that females are not passive to the attempts of males, no indication of proceptive behavior of females of this species is known. Considering that proceptive behavior is what initiates or increases the probability of a male exhibiting sexual behaviors directed at a female, the present study carried out behavioral observations in two groups of nurse sharks in reproductive period to identify possible proceptive behaviors. The present work identified a new behavior, here referred to as Body Movement (BM), as an indicator of proceptivity. This behavior corresponded on average to 47.68% of the reproductive behaviors performed by the females and its occurrence was positively correlated (r = 0.5143341 / p = 0.04152 - Spearman) with the occurrence of socio-reproductive behaviors of males. Being able to identify signs of proceptivity in animals is important to understand the reproductive context in which a group is found and to allow greater attention to animals that are able to reproduce, in order to create more efficient reproductive management programs to develop long-term sustainable population management. [ABSTRACT FROM AUTHOR]

Rats are gregarious and promiscuous and when a female enters the behavioral estrous, two or more males copulate alternately (mount, intromission or ejaculation are performed by any of them). This circumstance promotes male-male competition that in turns influences the copulatory behavior. Thus, olfactory and visual cues of rivals, in laboratory conditions, shorten the ejaculation latency. Other studies focusing in the presence of a rival found the increment in the sperm number. Until now it is unknown if the simultaneous presence of two males simultaneously influences the copulatory performance and seminal characteristics. Thus, the aim of the present work was to evaluate if sexual competition modifies the copulatory behavior, the sperm number and seminal plug. Sexually experienced Wistar rats were tested in two different copulatory contexts. Non-competitive mating (one male-one female), and competitive mating (two males-one female). The copulatory (mounts, intromissions and ejaculation) and seminal parameters (sperm count and copulatory plug) were analyzed. We found that under competition, there was a shortening of the ejaculation latency due to the reduction in the inter-intromission interval and in the number of intromissions. Respect to the ejaculate, the sperm number increased drastically but the seminal plug maintain its size and weight characteristics. Therefore, sexual competition in male rats affects copulatory behavior and sperm count but not the seminal plug. [ABSTRACT FROM AUTHOR]

In spite of hermaphroditism, most earthworm species reproduce by cross fertilization i.e. by the process of copulation of two mature partners. Mechanism of copulation in few earthworm species (Lumbricus terrestris) is known. However literature on neurosecretory control of copulation in earthworm is lacking. In the present study 30 pairs of conjugating earthworms of Eisenia fetida were collected from laboratory culture beds during 2016 of monsoon season. Cerebral and ventral ganglia of 10 pairs of conjugating earthworms and 20 pairs of post conjugation (2 hrs after separation, 4 hrs after separation) earthworms were fixed in Bouin's fluid for cytomorphological studies on their cerebral neurosecretory cells. Earthworms (10 numbers) debrained through anterior transection of first five segments (brain present in 3rd segment) by sterilized paragon knife were studied to observe conjugation if any. Cerebral and ventral ganglia of 5 pairs of preconjugating earthworms were considered as control. Cerebral and ventral ganglia of earthworms displayed chiefly two types of neurosecretory cells such as A cells and B cells. The A cells are deeply stained AFpositive cells arranged in upper cortical tier beneath the perineurium and generally exhibiting process of axonal transport. The B cells, generally larger in size than A cells, are lightly or moderately stained with or without axonal transport and lie in between cortical A cells and central fibrous neuropile. In the cerebral ganglia the A cells outnumbered the B cells, while in the ventral ganglia the opposite is true. Debrained E. fetida survived but did not conjugate. Secretory dynamics in the cerebral and ventral ganglionic neurosecretory cells A and B were recorded in pre-conjugating, conjugating and post-conjugating earthworms. Absence of conjugation in debrained worms and exhibition of the same in earthworms with brain and its changes in neurosecretory profile clearly indicate involvement of cerebral neurosecretion in the phenomenon of conjugation in earthworm. Our result indicates probable involvement of cerebral neurohormone in the process of conjugation in E. fetida. [ABSTRACT FROM AUTHOR]

Circulating testosterone is easily aromatized to estradiol and reduced to dihydrotestosterone in target tissues and elsewhere in the body. Thus, the actions of testosterone can be mediated either by the estrogen receptors, the androgen receptor or by simultaneous action at both receptors. To determine the role of androgens acting at the androgen receptor, we need to eliminate actions at the estrogen receptors. Alternatively, actions at the androgen receptor itself can be eliminated. In the present review, I will analyze the specific role of androgen receptors in male and female sexual behavior as well as in aggression. Some comments about androgen receptors and social recognition are also made. It will be shown that there are important differences between species, even between strains within a species, concerning the actions of the androgen receptor on the behaviors mentioned. This fact makes generalizations from one species to another or from one strain to another very risky. The existence of important species differences is often ignored, leading to many misunderstandings and much confusion. • Many androgens can be transformed both to estradiol and dihydrotestosterone. • Androgen-induced sex and aggression require estrogen and/or androgen receptors. • In males, the contribution of the estrogen receptor is species-specific. • In females, the importance of androgen receptors for behavior is species-specific. • Failure to consider species differences has led to confusion. [ABSTRACT FROM AUTHOR]

Rationale: The influence of the main dopaminergic brain regions controlling copulation, the medial preoptic area (mPOA) and the nucleus accumbens (NAcc), on male rat sexual behavior expression has not been fully established. Objective: This work analyzes the sexual effects of dopamine (DA) receptor activation in the mPOA or the NAcc of sexually active male rats, with an intact (sexually experienced) or a reduced (sexually exhausted) sexual motivation. Methods: The non-specific DA receptor agonist apomorphine and the D2-like receptor agonist quinpirole were infused into the mPOA or the NAcc of sexually experienced or sexually exhausted male rats and their sexual behavior recorded. Results: DA receptor activation neither in the mPOA nor in the NAcc modified the copulatory behavior of sexually experienced male rats. DA receptor stimulation in the NAcc, but not in the mPOA, reversed the characteristic sexual inhibition of sexually satiated rats, and D2-like receptors were found to participate in this effect. Conclusion: The optimal sexual performance of sexually experienced male rats cannot be further improved by DA receptor activation at either brain region. In sexually satiated rats, which are sexually inhibited and have a diminished sexual motivation, NAcc DA receptor stimulation appears to play a key role in their capacity to respond to a motivational significant stimulus, the receptive female, with the participation of D2-like receptors. Activation of DA receptors with the same drug, at the same dose and in the same brain region, produces different effects on copulatory behavior that depend on the animal's sexual motivational state. [ABSTRACT FROM AUTHOR]

Progesterone, a 'female' hormone, modulates sexual behaviors in male mammals. This modulation is well documented in laboratory animals, but it is as yet unknown whether progesterone is associated with testosterone and/or sexual behaviors in primates living in their natural environments. In this study, we collected a total of 426 fecal samples and approximately 453 h of behavioral data from five male Tibetan macaques ( Macaca thibetana) to study relationships between males' progesterone and testosterone levels and sexual behaviors. Our results showed a negative correlation between fecal testosterone and progesterone levels. Both hormones seasonally varied. For three of the five subjects, we also found that copulatory and sexually motivated behaviors were negatively correlated with fecal progesterone levels. While not significant for the other two males, this study provides insight into the relationship between progesterone and the sexual behaviors of male primates living in a natural environment. [ABSTRACT FROM AUTHOR]

In the present study, the aphrodisiac properties of the purple corn (Zea mays) in male rats were analyzed. The aqueous crude extract of purple corn (at 25, 50, and 75 mg/kg) was administered to (a) copulating male rats and (b) anesthetized and spinal cord transected male rats. Behavioral parameters of copulatory behavior and parameters of the genital motor pattern of ejaculation previous to its inhibition, under the influence of the purple corn extract, are described. Administration of the aqueous crude extract of purple corn significantly facilitates the arousal and execution of male rat sexual behavior without significant influences on the ambulatory behavior. In addition, purple corn extract elicit a significant increase in the number of discharges of the ejaculatory motor patterns and in the total number of genital motor patterns evoked in spinal rats. The present findings show that the aqueous crude extract of purple corn possesses aphrodisiac activity. [ABSTRACT FROM AUTHOR]

The behaviors that surround copulation are characterized as sociosexual behaviors. These behaviors displayed by males that are directed at females may include allogrooming, wrestling, chasing, approach, and time spent together. The data supported the hypothesis that the duration of sociosexual behaviors differs during the pre-copulatory, peri-copulatory, and post-copulatory phases of the mating bout in meadow voles. Voles spent more time approaching conspecifics during the pre- and peri-copulatory phases than during the post-copulatory phase. Voles spent more time allogrooming, wrestling, and chasing during the pre-copulatory phase than during the peri- and post-copulatory phases. Voles spent similar amounts of time together during the pre-, peri-, and post-copulatory phases. The data suggest that sociosexual behaviors displayed by males may be involved in setting the pace and temporal components of the mating bout. During the pre-copulatory phase particular behaviors by male voles may attract females, during the peri-copulatory phase some of these behaviors may stimulate or motivate the female to mate, and during the post-copulatory phase certain behaviors may prepare the male to mate again [Current Zoology 57 (1): 43–49, 2011].

We studied the effects of adverse conditions such as constant light (LL) on the circadian rhythm of malate (MDH, EC 1.1.1.37) and lactate (LDH, EC 1.1.1.27) dehydrogenase activities of the testes of male Wistar rats on postnatal day 28 (PN28), anxiety-like behavior (elevated plus-maze test) at PN60 and sexual behavior at PN120. The rats were assigned to mother groups on day 10 of pregnancy: control (12-h light/dark), LL (light from day 10 to 21 of pregnancy), and LL+Mel (LL and sc injection to the mothers of a daily dose of melatonin, 1 mg/kg body weight at circadian time 12, from day 17 to 21 of pregnancy). LL offspring did not show circadian rhythms of MDH (N = 62) and LDH (N = 63) activities (cosinor and ANOVA-LSD Fisher). They presented a 44.7% decrease in open-arm entries and a 67.9% decrease in time (plus-maze test, N = 15, P < 0.001, Mann-Whitney U-test and Kruskal-Wallis test), an increase in mounting (94.4%), intromission (94.5%) and ejaculation (56.6%) latencies (N = 12, P < 0.01, Mann-Whitney U-test and Kruskal-Wallis test) and lower numbers of these events (61, 59 and 73%, respectively; P < 0.01, N = 12) compared to controls. The offspring of the LL+Mel group presented MDH and LDH circadian rhythms (P < 0.05, N = 50, cosinor and ANOVA-LSD Fisher), anxiety-like and sexual behaviors similar to control. These findings supported the importance of the melatonin signal and provide evidence for the protective effects of hormones on maternal programming during gestation. This protective action of melatonin is probably related to its entrainment capacity, favoring internal coupling of the fetal multioscillatory system.

Polyandry is widespread across animal taxa and subjects males to intense postcopulatory sexual selection which favors adaptations that enhance a male's paternity success, either by decreasing the risk of sperm competition and/or by increasing the competitiveness of the ejaculate. Copulatory plugs deposited by males are thought to have evolved in the context of sperm competition. However, experimental studies that assess the function of copulatory plugs remain scarce. Moreover, most studies have used unnatural manipulations, such as ablating plug-producing male glands or interrupting copulations. Here, we investigated whether repeated ejaculation affects plug size in a mammalian model species, the house mouse. When males experience short periods of sexual rest we found that plug size decreased over repeated ejaculations so that time since last ejaculation can be applied as an approximation for plug size. We induced natural variation in plug size arising from variation in male sexual restedness and investigated the behavior and paternity success of rival males. Male behavior in the offensive mating role (second) was influenced, albeit not significantly, by the sexual restedness of the first male to mate, and therefore the size of his plug. However, second males sired a significantly greater proportion of embryos when competing against a male that had recently mated compared with a male that had not. This supports a potential role of the plug in promoting a male's competitive fertilization success when remating occurs, which could be mediated both by delaying female remating and by ensuring efficient sperm transport through the female reproductive tract. [ABSTRACT FROM AUTHOR]

Dopamine influences the anticipatory and consummatory phases of sexual behavior, by acting on receptors of the D2 family (D 2 , D 3 and D 4 ) and in particular of the D 2 subtype, although evidence for a role of D 4 receptors in erectile function and copulatory behavior is also available. In order to clarify such a role of D 4 receptors, the effect of selective D 4 receptor agonists and antagonists on copulatory behavior of sexually potent male rats in classic copulation tests with a receptive female, was compared with that of apomorphine and haloperidol, a classic dopamine receptor agonist and antagonist, respectively. PD-168,077 (0.05–0.2 mg/kg) and ABT-724 (0.01–0.04 mg/kg), two selective D 4 receptor agonists, given subcutaneously, improved dose-dependently copulatory behavior as shown by the decrease of mount frequency and post ejaculatory interval induced by PD-168,077, and of mount frequency, ejaculation latency, post ejaculatory and inter intromission intervals induced by ABT-724, and by the increase of ejaculation frequency and copulatory efficacy induced by both drugs. Conversely, L-745,870 (1–5 mg/kg), a selective D 4 receptor antagonist, given intraperitoneally, impaired dose-dependently copulatory behavior, as shown by the increase in intromission and ejaculation latencies, mount frequency, post ejaculatory interval and the decrease in ejaculation frequency and copulatory efficacy induced by this drug. L-745,870 (5 mg/kg) administered before PD-168,077 (0.2 mg/kg) or ABT-724 (0.04 mg/kg), also abolished completely the facilitatory effects of both PD-168,077 and ABT-724 on sexual behavior. These results confirm the involvement of D 4 receptors in specific aspects of male rat copulatory behavior that overlap only partially with those influenced by apomorphine and haloperidol. [ABSTRACT FROM AUTHOR]

Although male testosterone levels are thought to be linked with the mating system, ecological and social factors complicate the big picture of the function of testosterone in wild nonhuman primates. We examined testosterone correlates with rank and copulatory behavior in male Tibetan macaques (Macaca thibetana) at Mt. Huangshan, China. A total of 426 fecal samples and approximately 453h of behavioral data were collected on five adult males from October 2005 to September 2006. Copulatory behaviors were significantly different between high and low ranking males in the mating season, but not during the non-mating season. No significant correlation between testosterone levels and a male's David's score indicated that testosterone was independent of social rank. Also, copulatory behaviors were positively correlated with fecal testosterone levels in both seasons, regardless of social rank. The present study represents a preliminary assessment of the relationship between testosterone level, rank, and copulatory behavior in a wild environment. The results enrich the picture of testosterone, rank, and copulatory relationships in non-human primates, and may also provide insight into what mechanisms link physiological factors to male reproductive success in natural circumstances. [ABSTRACT FROM AUTHOR]

Different studies dealing with ejaculation view this process as a part of the male copulatory behavior. Some of them explain ejaculation as the consequence of a neuroendocrine feedback loops or from a purely anatomical perspective. The goal of the present review is to discuss the traditional and novel themes related to the biology of ejaculation. The text begins with the description of the behavioral motor patterns that lead to ejaculation. The anatomo-physiological mechanisms are explained under the notion that ejaculation is more than genitals and an excurrent duct system; thus it is also included the participation of the striated perineal musculature. Although ejaculation is a sexual spinal reflex, it is inhibited tonically by supraspinal structures. Such supraspinal modulation may explain the prudent sperm allocation, by which males adjust the number of sperm per ejaculate while copulating under distinct competitive scenarios. In some mammals, ejaculate components facilitate seminal coagulation, an adaptation that may increase the male reproductive fitness. Finally, there is a reflection of the so-called human ejaculatory disturbances, which from an ecophysiolgical perspective could represent advantages instead of sexual malfunction as are recognize under the medical view.

Estrogens have been shown to rapidly promote male copulatory behaviors with a time-course that suggests rapid signaling events are involved. The present study tested the hypothesis that estrogen acts through a novel Gq protein-coupled membrane estrogen receptor (ER). Thus, either estradiol (E2), STX (a diphenylacrylamide compound that selectively activates a membrane ER pathway), or vehicle were administered acutely to castrated male rats that bore subcutaneous (sc) dihydrotestosterone implants to maintain genital sensitivity. Appetitive (level changes, genital investigation) and consummatory (mounts, intromissions, ejaculations) components of male sexual behavior were measured in a bilevel testing apparatus. Testing showed that E2 treatment promoted olfactory and mounting behaviors, but had no effect on motivation as measured by anticipatory level changes. STX treatment showed no effect on either component of male sexual behavior. These results support previous results that showed that E2 can rapidly affect male sexual behaviors but fail to support a role for the specific membrane-initiated pathway activated by STX. [ABSTRACT FROM AUTHOR]

Summary: It is increasingly recognized that estrogens produce rapid and transient effects at many neural sites ultimately impacting physiological and behavioral endpoints. The ability of estrogens to acutely regulate cellular processes implies that their concentration should also be rapidly fine-tuned. Accordingly, rapid changes in the catalytic activity of aromatase, the limiting enzyme for estrogen synthesis, have been identified that could serve as a regulatory mechanism of local estrogen concentrations. However, the precise anatomical localization, time-course, triggering stimuli and functional significance of these enzymatic changes in vivo are not well understood. To address these issues as to where, when and why aromatase activity (AA) rapidly changes after sexual interactions, AA was assayed in six populations of aromatase-expressing cells microdissected from the brain of male quail that experienced varying durations of visual exposure to or copulation with a female. Sexual interactions resulted in a rapid AA inhibition. This inhibition occurred in specific brain regions (including the medial preoptic nucleus), in a context-dependent fashion and time-scale suggestive of post-translational modifications of the enzyme. Interestingly, the enzymatic fluctuations occurring in the preoptic area followed rather than preceded copulation and were tied specifically to the female''s presence. This pattern of enzymatic changes suggests that rapid estrogen effects are important during the motivational phase of the behavior to trigger physiological events essential to activate mate search and copulation. [Copyright &y& Elsevier]

Abstract: There is increasing evidence that exposure to stressors in adolescence has long-lasting effects on emotional and cognitive behavior, but little is known as to whether reproductive functions are affected. We investigated appetitive and consummatory aspects of sexual behavior in male rats that were exposed to chronic social instability stress (SS, n=24) for 16days in mid-adolescence compared to control rats (CTL, n=24). Over five sexual behavior test sessions with a receptive female, SS rats made fewer ejaculations (p=0.02) and had longer latencies to ejaculation (p=0.03). When only data from rats that ejaculated in the fifth session were analyzed, SS rats (n=18) had reduced copulatory efficiency (more mounts and intromissions before ejaculation) compared to CTL rats (n=19) (p=0.004), and CTL rats were twice as likely as SS rats to make more than one ejaculation in the fifth session (p=0.05). Further, more CTL (14/24) than SS (5/25) rats ejaculated in four or more sessions (p=0.05). SS rats had lower plasma testosterone concentrations than CTL rats (p=0.05), but did not differ in androgen receptor, estrogen receptor alpha, or Fos immunoreactive cell counts in the medial preoptic area. The groups did not differ in a partner preference test administered between the fourth and fifth sexual behavior session. The results suggest that developmental history contributes to individual differences in reproductive behavior, and that stress exposures in adolescence may be a factor in sexual sluggishness. [Copyright &y& Elsevier]

Abstract: Male rat copulation is mediated by estrogen-sensitive neurons in the medial preoptic area (MPO) and medial amygdala (MEA); however, the mechanisms through which estradiol (E2) acts are not fully understood. We hypothesized that E2 acts through estrogen receptor α (ERα) in the MPO and MEA to promote male mating behavior. Antisense oligodeoxynucleotides (AS-ODN) complementary to ERα mRNA were bilaterally infused via minipumps into either brain area to block the synthesis of ERα, which we predicted would reduce mating. Western blot analysis and immunocytochemistry revealed a knockdown of ERα expression in each brain region; however, compared to saline controls, males receiving AS-ODN to the MPO showed significant reductions in all components of mating, whereas males receiving AS-ODN to the MEA continued to mate normally. These results suggest that E2 acts differently in these brain regions to promote the expression of male rat sexual behavior and that ERα in the MPO, but not in the MEA, promotes mating. [Copyright &y& Elsevier]

Diabrotica speciosa (Germar) is an economically important pest of Neotropical cultures and represents a quarantine risk for Neartic and Paleartic Regions. Despite its agricultural importance, few studies have been done on mating behavior and chemical communication, which has delayed the development of behavioral techniques for population management, such as the use of pheromone traps. In this study, we determined 1) the age at first mating; 2) diel rhythm of matings; 3) number of matings over 7 d; 4) the sequence of D. speciosa activities during premating, mating, and postmating; 5) the duration of each activity; and 6) response to male and female conspecific volatiles in Y-tube olfactometer. The first mating occurred between the third and seventh day after adult emergence and the majority of pairs mated on the fourth day after emergence. Pairs of D. speciosa showed a daily rhythm of mating with greater sexual activity between the end of the photophase and the first half of the scotophase. During the 7 d of observation, most pairs mated only once, although 30% mated two, three, or four times. In a Y-tube olfactometer, males were attracted by virgin females as well as by the volatile compounds emitted by females. Neither males nor their volatiles were attractive to either sex. Our observation provide information about mating behavior of D. speciosa, which will be useful in future research in chemical communication, such as identification of the pheromone and development of management techniques for this species using pheromone traps. [ABSTRACT FROM AUTHOR]

Experiments confirmed that female Pseudococcus longispinus (Targioni Tozzetti), Pseudococcus viburni (Signoret), and Planococcusficus Signoret (Hemiptera: Pseudococcidae) must mate to produce viable offspring. Females of all three species were capable of mating multiple times on the same day and on sequential days (range, 1-8 times). Female reproductive output was not increased by multiple copulations. Male P. longispinus, P. viburni, and P. ficus also mated multiple times during their lifetimes (maximum of 9, 11, and 19 times, respectively). Male P.ficus had the highest mean number of copulations (9.6 ± 0.6), followed by P. longispinus and P. viburni. More than half of the P. ficus males survived their first day of copulations and remated the next day when presented with unmated females. P. viburni males also readily mated with unmated females on the day subsequent to their first copulations. Median times between copulations were short for males of all species (<2 min). Constant exposure to pheromone had no detectable effect on the activity levels of male P. ficus and P. longispinus, whereas P. viburni males exposed to pheromone emerged significantly earlier from their cocoons than control males without pheromone exposure. Constant exposure to pheromone had no effect on the longevity of males of any species compared with controls. The implications of the results of these experiments for pheromone-based methods of managing mealybugs are discussed. [ABSTRACT FROM AUTHOR]

Complex genitalia occur in many arthropods and in some species extreme female morphologies lead to serious mechanical difficulties for males. Tephritid flies offer examples of such complex genitalia. Because of their economic importance and the extensive use of sterile male releases for tephritid control in Texas and Mexico, studies have been done on various aspects of their basic reproductive biology, but the process of intromission has received little attention. The distiphallus of the male of Anastrepha ludens is complex. One membranous sac on the distiphallus is capable of rhythmic cycles of inflation and deflation. Inflations of the sac near the base of the distiphallus probably help propel the aedeagus deeper into the female along with stiffening of the basiphallus and may drive the genital rod (which does not transfer sperm) into the ventral receptacle. We were unable to establish an association between some of the behaviours displayed by males during mating and intromission process. Rev. Biol. Trop. 59 (1): 291-297. Epub 2011 March 01. [ABSTRACT FROM AUTHOR]

The behaviors that surround copulation are characterized as sociosexual behaviors. These behaviors displayed by males that are directed at females may include allogrooming, wrestling, chasing, approach, and time spent together. The data supported the hypothesis that the duration of sociosexual behaviors differs during the pre-copulatory, peri-copulatory, and post-copulatory phases of the mating bout in meadow voles. Voles spent more time approaching conspecifics during the pre- and peri-copulatory phases than during the post-copulatory phase. Voles spent more time allogrooming, wrestling, and chasing during the pre-copulatory phase than during the peri- and post-copulatory phases. Voles spent similar amounts of time together during the pre-, peri-, and post-copulatory phases. The data suggest that sociosexual behaviors displayed by males may be involved in setting the pace and temporal components of the mating bout. During the pre-copulatory phase particular behaviors by male voles may attract females, during the peri-copulatory phase some of these behaviors may stimulate or motivate the female to mate, and during the post-copulatory phase certain behaviors may prepare the male to mate again [Current Zoology 57 (1): 43-49, 2011]. [ABSTRACT FROM AUTHOR]

Mongolian Gerbils are often used as a biological model, but it remains unclear whether these rodents display nocturnal, diurnal, or crepuscular patterns of behavior. The experiments presented below studied patterns of sleep-activity, feeding, and reproductive behavior under 12:12 light dark cycles. All data from these experiments suggest a nocturnal pattern of behavior in these rodents. [ABSTRACT FROM AUTHOR]

Purpose: The dopamine-derived endogenous compound, R-salsolinol (SAL), was recently identified as a putative endogenous prolactin (PRL)-releasing factor. However, how SAL influences copulatory behavior is unknown. In this study, we examined the relationship between SAL and copulatory behavior in male rats. Methods: Male Sprague-Dawley rats administered SAL were exposed to female rats in estrus, the plasma PRL concentration was measured, and the behavioral frequency and time during copulatory behavior were noted. Results: In the control and SAL groups, plasma PRL concentrations at 15 min before exposure to the female were 7.3 ± 2.0 and 8.0 ± 1.5 ng/ml, respectively. Moreover, plasma PRL concentrations in males immediately after exposure to the female were 7.4 ± 1.2 and 68.0 ± 5.9 ng/ml, respectively ( P < 0.05). All (8/8) of the control animals ejaculated in the presence of the female, whereas only 33% (2/6) of the SAL group ejaculated. An increasing tendency for mount latency and intromission latency and a decreasing tendency for intromission frequency were observed in the SAL group. Conclusions: Copulatory behavior was inhibited in male rats after SAL injection, suggesting that SAL is a copulatory behavior inhibiting factor. [ABSTRACT FROM AUTHOR]

Abstract: Neural aromatization of testosterone (T) to estrogen during development is thought to be important for sexual differentiation of many altricial mammals. We evaluated the effects of neonatal injections of the non-aromatizable androgen dihydrotestosterone propionate (DHTP) and estradiol (E2) on the copulatory behavior of the female musk shrew, an altricial insectivore. Following adult ovariectomy and replacement T, animals were paired with a stimulus female for two 60-minute copulatory behavior tests. The latency to induce sexual receptivity (in the form of tail-wagging by the female), mount latency and total number of mounts were recorded in experimental females and in a group of untreated control males. While neither hormone treatment significantly affected mounting behavior, DHTP-treated animals induced receptivity faster and with latencies not significantly different from intact males, suggesting that early non-aromatizable androgens can have masculinizing actions by either increasing sexual motivation or making the treated animal more attractive to the stimulus female. Reliance on androgenic rather than estrogenic metabolites for the differentiation of courtship behaviors conforms to the pattern seen more typically in primates than rodents. [Copyright &y& Elsevier]

Abstract: Estrogen production by the female avian embryo induces development of a female phenotype of the reproductive organs whereas the low estrogen concentration in the male embryo results in a male phenotype. Treatment of female embryos with exogenous estrogens disrupts Müllerian duct development resulting in malformations and impaired oviductal function. Exposure of male embryos to estrogens results in ovotestis formation and persisting Müllerian ducts in the embryos and testicular malformations, reduced semen production and partially developed oviducts in the adult bird. Furthermore, studies in Japanese quail show that the male copulatory behavior is impaired by embryonic estrogen treatment. Results from our experiments with selective agonists for ERα and ERβ suggest that the effects of estrogens on the reproductive organs are mediated via activation of ERα. Abundant expression of ERα mRNA was shown in gonads and Müllerian ducts of early Japanese quail embryos. Both ERα and ERβ transcripts were detected by real-time PCR in early embryo brains of Japanese quail indicating that both receptors may be involved in sex differentiation of the brain. However, in 9-day-old quail embryo brains in situ hybridization showed expression of ERβ mRNA, but not of ERα mRNA, in the medial preoptic nucleus (POM) and the bed nucleus of the stria terminalis (BSTm), areas implicated in copulatory behavior of adult male quail. Furthermore, embryonic treatment with the selective ERα agonist propyl pyrazol triol (PPT) had no effect on the male copulatory behavior. These results suggest that ERβ may be important for the effects of estrogens on brain differentiation. [Copyright &y& Elsevier]

Abstract: Until the second half of the 20th century, it was broadly accepted that most birds are microsmatic if not anosmic and unable to detect and use olfactory information. Exceptions were eventually conceded for species like procellariiforms, vultures or kiwis that detect their food at least in part based on olfactory signals. During the past 20–30 years, many publications have appeared indicating that this view is definitely erroneous. We briefly review here anatomical, electrophysiological and behavioral data demonstrating that birds in general possess a functional olfactory system and are able to use olfactory information in a variety of ethological contexts, including reproduction. Recent work also indicates that brain activation induced by sexual interactions with a female is significantly affected by olfactory deprivation in Japanese quail. Brain activation was measured via immunocytochemical detection of the protein product of the immediate early gene c-fos. Changes observed concerned two brain areas that play a key role in the control of male sexual behavior, the medial preoptic nucleus and the bed nucleus of the stria terminalis therefore suggesting a potential role of olfaction in the control of reproduction. The widespread idea that birds are anosmic or microsmatic is thus not supported by the available experimental data and presumably originates in our anthropomorphic view that leads us to think that birds do not smell because they have a rigid beak and nostrils and do not obviously sniff. Experimental analysis of this phenomenon is thus warranted and should lead to a significant change in our understanding of avian biology. [Copyright &y& Elsevier]

In birds as in other vertebrates, estrogens produced in the brain by aromatization of testosterone have widespread effects on behavior. Research conducted with male Japanese quail demonstrates that effects of brain estrogens on all aspects of sexual behavior, including appetitive and consummatory components as well as learned aspects, can be divided into two main classes based on their time course. First, estrogens via binding to estrogen receptors regulate the transcription of a variety of genes involved primarily in neurotransmission. These neurochemical effects ultimately result in the activation of male copulatory behavior after a latency of a few days. Correlatively, testosterone and its aromatized metabolites increase the transcription of the aromatase mRNA, resulting in an increased concentration and activity of the enzyme that actually precedes behavioral activation. Second, recent studies with quail demonstrate that brain aromatase activity can also be modulated within minutes by phosphorylation processes regulated by changes in intracellular calcium concentration, such as those associated with glutamatergic neurotransmission. The rapid upregulations or downregulations of brain estrogen concentration (presumably resulting from these changes in aromatase activity) affect, by nongenomic mechanisms with relatively short latencies (frequency increases or decreases respectively within 10–15 min), the expression of male sexual behavior in quail and also in rodents. Brain estrogens thus affect behavior on different time scales by genomic and nongenomic mechanisms similar to those of a hormone or a neurotransmitter. [ABSTRACT FROM AUTHOR]

Abstract: When ovariectomized/adrenalectomized female rats, injected with subthreshold doses of estradiol are given copulatory stimulation by a male rat at half hour intervals, the level of lordosis gradually increases over the course of a few hours. We tested the hypothesis that paracopulatory behaviors (behaviors that occur repetitively prior to and between mounts), also generally considered to be heavily dependent on progesterone, are enhanced by this stimulation as well. We have reported previously that the enhancement of copulatory behavior is dependent to a large extent on intromissive stimulation by the male. In the present study, mating stimulation induced high levels of paracopulatory behaviors, as well as lordosis. Surprisingly, though, and in contrast to previous findings, this increase was seen not only in rats receiving intromissive stimulation, but in those receiving non-intromissive stimulation as well. Furthermore, intromissive stimulation induced high levels of rejection behavior. In a subsequent experiment, experimenter-induced, mechanical stimulation increased only rejection behaviors, not copulatory behavior. The results collectively demonstrate that, under the conditions used in these experiments, non-intromissive stimulation is sufficient for inducing both copulatory and paracopulatory behaviors in estradiol-primed rats. However, under the conditions used in these studies, intromissive stimulation increases rejection behaviors. [Copyright &y& Elsevier]

Several of the drugs currently available for the treatment of premature ejaculation (PE) (e.g., local anesthetics or antidepressants) are associated with numerous safety concerns and exhibit weak efficacy. To date, no therapeutics for PE have been approved in the United States, highlighting the need to develop novel agents with sufficient efficacy and fewer side effects. In this study, we focused on the histamine H3 receptor (H3R) as a potential target for the treatment of PE and evaluated the effects of imetit (an H3R/H4R agonist), ciproxifan (an H3R antagonist), and JNJ-7777120 (an H4R antagonist) in vivo. Our in vivo electrophysiological experiments revealed that imetit reduced mechanical stimuli-evoked neuronal firing in anesthetized rats. This effect was inhibited by ciproxifan but not by JNJ-7777120. Subsequently, we evaluated the effect of imetit using a copulatory behavior test to assess ejaculation latency (EL) in rats. Imetit prolonged EL, although this effect was inhibited by ciproxifan. These findings indicate that H3R stimulation suppresses mechanical stimuli-evoked neuronal firing in the spinal–penile neurotransmission system, thereby resulting in prolonged EL. To our knowledge, this is the first report to describe the relationship between H3R and PE. Thus, H3R agonists may represent a novel treatment option for PE. [ABSTRACT FROM AUTHOR]

Abstract: In rats, expression of the immediate early gene, c-fos observed in the brain following male copulatory behavior relates mostly to the detection of olfactory information originating from the female and to somatosensory feedback from the penis. However, quail, like most birds, are generally considered to have a relatively poorly developed sense of smell. Furthermore, quail have no intromittent organ (e.g., penis). It is therefore intriguing that expression of male copulatory behavior induces in quail and rats a similar pattern of c-fos expression in the medial preoptic area (mPOA), bed nucleus of the stria terminalis (BSTM) and parts of the amygdala. We analyzed here by immunocytochemistry Fos expression in the mPOA/BSTM/amygdala of male quail that had been allowed to copulate with a female during standardized tests. Before these tests, some of the males had either their nostrils plugged, or their cloacal area anesthetized, or both. A control group was not exposed to females. These manipulations did not affect frequencies of male sexual behavior and all birds exposed to a female copulated normally. In the mPOA, the increased Fos expression induced by copulation was not affected by the cloacal gland anesthesia but was markedly reduced in subjects deprived of olfactory input. Both manipulations affected copulation-induced Fos expression in the BSTM. No change in Fos expression was observed in the amygdala. Thus immediate early gene expression in the mPOA and BSTM of quail is modulated at least in part by olfactory cues and/or somatosensory stimuli originating from the cloacal gland. Future work should specify the nature of these stimuli and their function in the expression of avian male sexual behavior. [Copyright &y& Elsevier]

Abstract: Depressive disorders have a worldwide high prevalence. Fluoxetine (FLX), a selective serotonin reuptake inhibitor (SSRI) antidepressant, has been widely prescribed for depression during pregnancy and/or lactation. Since serotonin is a neurotrophic factor, the use of FLX by mothers could disrupt brain development resulting in behavioral alterations in their progeny. The aim of the present study was to evaluate the effects of developmental FLX exposure on sexual behavior, as well as on endocrine parameters, of male mice. Swiss dams were treated daily, by gavage, with 7.5 mg/kg of FLX during pregnancy and lactation. Male pups were tested for copulatory behavior and sexual incentive motivation. Male pups also had their anogenital distance, plasmatic testosterone concentration and testis, epididymis, seminal vesicle and pituitary wet weights assessed. Copulatory behavior, anogenital distance, plasmatic testosterone concentration and organs wet weights were not affected by FLX exposure. However, this exposure eliminated preference for a sexual incentive on the sexual incentive motivation test, which indicates reduced sexual motivation, a classic side effect of SSRIs in humans who take these antidepressants. [Copyright &y& Elsevier]

Abstract: Several proerectile drugs act on the nitric oxide–cyclic guanosine monophopsphate pathway, which is known to influence rat copulatory behavior. In the present study we evaluated the effects of two proerectile compounds, one (Impaza) acting on endothelial nitric oxide synthase, and the other (sildenafil) on phosphodiesterase 5, on sexual incentive motivation in male rats displaying a spontaneously low level of motivation and copulatory behavior. About 20 months old male Fisher 344 rats were tested in a procedure for evaluating the intensity of sexual incentive motivation and in standard mating tests. For comparison, a group of young (about 4 months) Fisher 344 males was tested in parallel. This group did not receive any drug treatment. Impaza was administered in two doses, daily for 28 days, and sildenafil was given at a dose of 3 mg/kg twice a week during 28 days. Tests for sexual incentive motivation and copulatory behavior were performed immediately before the beginning of drug treatments, and on days 7, 14 and 28 of treatment. All treatment groups displayed a very low level of copulatory behavior and a sexually receptive female was not a more powerful incentive than another male at the tests performed before and on days 7 and 14 of treatment. On day 28 of treatment, the group treated with Impaza, 3 ml, displayed a preference for the sexually receptive female, while no such preference was found in the other groups. Furthermore, the preference score was above that of controls in this group. Both Impaza, 3 ml, and sildenafil reduced approach to the male in the test for sexual incentive motivation, suggesting that social motivation was reduced. These data suggest that compounds affecting the nitric oxide–cyclic guanosine monophopsphate pathway may modify both sexual and social motivation in old rats. [Copyright &y& Elsevier]

We investigated the hypothesis that predation risk affects mating decisions in the intertidal snail Littorina plena in Bamfield Inlet, Northeast Pacific. First, we conducted a field tethering experiment to test the assumption that mating pairs of snails are more susceptible to predation than solitary individuals, and then performed a laboratory experiment to quantify the effect of predation threat on the propensity of snails to form mating pairs. Our results support the hypothesis, in that “mating pairs” were more frequently killed than single snails in the field, and snails were less likely to form mating pairs in the laboratory when simulated predation risk was high (chemical cues from crushed conspecifics were added to the water) than when it was low (no risk cues were added to the water). In contrast to several earlier studies, we found no effect of individual size on snail susceptibility to predation, perhaps because our two size classes were contiguous and snails within them were not dissimilar enough. The results of the behavioral experiment were consistent with this lack of individual size effect on snail vulnerability; both size classes of snails showed a significant and similar tendency to decrease mating when predation risk was high. Taken together, the results of this and recent studies indicate that predators can considerably affect the behavior of littorinid snails, including their movement patterns, feeding, and reproduction. We argue that greater consideration should be given to how marine invertebrates trade off predation risk and activities related to reproduction. [ABSTRACT FROM AUTHOR]

Abstract: Estrogens exert a wide variety of actions on reproductive and non-reproductive functions. These effects are mediated by slow and long lasting genomic as well as rapid and transient non-genomic mechanisms. Besides the host of studies demonstrating the role of genomic actions at the physiological and behavioral level, mounting evidence highlights the functional significance of non-genomic effects. However, the source of the rapid changes in estrogen availability that are necessary to sustain their fast actions is rarely questioned. For example, the rise of plasma estrogens at pro-estrus that represents one of the fastest documented changes in plasma estrogen concentration appears too slow to explain these actions. Alternatively, estrogen can be synthesized in the brain by the enzyme aromatase providing a source of locally high concentrations of the steroid. Furthermore, recent studies demonstrate that brain aromatase can be rapidly modulated by afferent inputs, including glutamatergic afferents. A role for rapid changes in estrogen production in the central nervous system is supported by experiments showing that acute aromatase inhibition affects nociception as well as male sexual behavior and that preoptic aromatase activity is rapidly (within min) modulated following mating. Such mechanisms thus fulfill the gap existing between the fast actions of estrogen and their mode of production and open new avenues for the understanding of estrogenic effects on the brain. [Copyright &y& Elsevier]

We report the first case of sperm wasting produced by females running away just before a male ejaculates. Consequently, males ejaculate outside the reproductive tract of the female. This behavior was observed at least once in 32.14% of 112 copulatory tests of meadow voles, Microtus pennsylvanicus. We found a negative correlation between percentage of external ejaculations experienced by males and the number of sperm allocated within the female reproductive tract. Thus, females may limit the fertilizing capacity of non-preferred males by causing them to ejaculate externally. The occurrence of external ejaculations was not affected by cues of other males, male body mass, female sexual experience, or male sexual experience. Our results expand the growing view that females may be active participants in copulatory behavior and largely determine the fate and use of sperm. [ABSTRACT FROM AUTHOR]

In rodents, male-typical copulatory behavior is generally dependent on gonadal sex steroids such as testosterone, and it is thought that the mechanism by which the hormone gates the behavior involves the gaseous neurotransmitter nitric oxide. According to one model, testosterone induces an up-regulation of nitric oxide synthase (NOS) in the preoptic area, increasing nitric oxide synthesis following exposure to a sexual stimulus. Nitric oxide in turn, possibly through its effect on catecholamine turnover, influences the way the stimulus is processed and enables the appropriate copulatory behavioral response. In whiptail lizards (genus Cnemidophorus), administration of male-typical levels of testosterone to females induces the display of male-like copulatory responses to receptive females, and we hypothesized that this radical change in behavioral phenotype would be accompanied by a large change in the expression of NOS in the preoptic area. As well as comparing NOS expression using NADPH diaphorase histochemistry between testosterone-treated females and controls, we examined citrulline immunoreactivity (a marker of recent nitric oxide production) in the two groups, following a sexual stimulus and following a nonsexual stimulus. Substantially more NADPH diaphorase-stained cells were observed in the testosterone-treated animals. Citrulline immunoreactivity was greater in testosterone-implanted animals than in blank-implanted animals, but only following exposure to a sexual stimulus. This is the first demonstration that not only is NOS up-regulated by testosterone, but NOS thus up-regulated is activated during male-typical copulatory behavior. © 2006 Wiley Periodicals, Inc. J Neurobiol, 2006 [ABSTRACT FROM AUTHOR]

Abstract: It is well established that sex steroid hormones bind to nuclear receptors, which then act as transcription factors to control brain sexual differentiation and the activation of sexual behaviors. Estrogens locally produced in the brain exert their behavioral effects in this way but mounting evidence indicates that estrogens also can influence brain functioning more rapidly via non-genomic mechanisms. We recently reported that, in Japanese quail, the activity of preoptic estrogen synthase (aromatase) can be modulated quite rapidly (within minutes) by non-genomic mechanisms, including calcium-dependent phosphorylations. Behavioral studies further demonstrated that rapid changes in estrogen bioavailability, resulting either from a single injection of a high dose of estradiol or from the acute inhibition of aromatase activity, significantly affect the expression of both appetitive and consummatory aspects of male sexual behavior with latencies ranging between 15 and 30 min. Together these data indicate that the bioavailability of estrogens in the brain can change on different time-scales (long- and short-term) that match well with the genomic and non-genomic actions of this steroid and underlie two complementary mechanisms through which estrogens modulate behavior. Estrogens produced locally in the brain should therefore be considered not only as neuroactive steroids but they also display many (if not all) functional characteristics of neuromodulators and perhaps neurotransmitters. [Copyright &y& Elsevier]

It is well known that male wild boars (Sus scrofa) are usually solitary. However, during the mating season, they compete for females which may bias their mate choice toward some of the males breed. In order to determinate whether or not a precopulatory choice occurs in captivity, 18 yorklandrace multiparous females (Y/N) were mated with three males belonging to three breeds: yorkshire (Y/Y), yorklandrace (Y/N), landrace (N/N). Copulation preference, precopulatory and copulatory behaviors, as well as the female-female interactions were registered. During the precopulatory phase, in terms of time, the Y/N male received more female attention (53.7%) than the other males. Additionally, Y/Y male more frequently displayed behaviors as "teeth chattering" (83.33%), "vocalization" (56.52%) and "trumping" (64%). "Vagina smelling" was more frequently displayed by N/N male (48%) and "biting" by Y/N male (60%). During the copulation, Y/N male displayed significantly more "nose-vagina" behavior (41%) and N/N male, the "vocalization" behavior (46.9%). Four females recently copulated by males, were mounted by other females in estrus producing an expulsion of both the seminal tap and the ejaculate. The results show a strong behavioral competition between the three males and a female precopulatory preference by the heterozygous Y/N male. A possible explanation to this phenomenon is that the Y/N male odoripherous secretions from both, salivary and prepucial glands; carry information about his genetic quality. Female-female mounting is probably an expression of intra-sexual competition, reducing chances for fertilization. [ABSTRACT FROM AUTHOR]

Abstract: Steroids are generally viewed as transcription factors binding to intracellular receptors and activating gene transcription. Rapid cellular effects mediated via non-genomic mechanisms have however been identified and one report showed that injections of estradiol rapidly stimulate chemoinvestigation and mounting behavior in castrated male rats. It is not known whether such effects take place in other species and what are the cellular underlying mechanisms. We show here that a single injection of estradiol (500μg/kg) rapidly and transiently activates copulatory behavior in castrated male quail pre-treated with a dose of testosterone behaviorally ineffective by itself. The maximal behavioral effect was observed after 15min. In a second experiment, the brain of all subjects was immediately collected after behavioral tests performed 15min after injection. The preoptic area—hypothalamus (HPOA), hindbrain, telencephalon and cerebellum were isolated and monoamines measured by HPLC-ED. Estradiol increased levels of the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) and 5-HIAA/serotonin ratios in the telencephalon and hindbrain independently of whether animals had mated or not. Estradiol also affected these measures in HPOA and cerebellum but this effect was correlated with the level of sexual activity so that significant effects of the treatment only appeared when sexual activity was used as a covariate. Interactions between estradiol effects and sexual activity were also observed for dopamine in the HPOA and for serotonin in the hindbrain and cerebellum. Together, these data demonstrate that a single estradiol injection rapidly activates male sexual behavior in quail and that this behavioral effect is correlated with changes in monoaminergic activity. [Copyright &y& Elsevier]