Nervous systems must not only generate specific adaptive behaviors, such as reproduction, aggression, feeding, and sleep, but also select a single behavior for execution at any given time, depending on both internal states and external environmental conditions. Despite their tremendous biological importance, the neural mechanisms of action selection remain poorly understood. In the past decade, studies in the model animal Drosophila melanogaster have demonstrated valuable neural mechanisms underlying action selection of innate behaviors. In this review, we summarize circuit mechanisms with a particular focus on a small number of sexually dimorphic neurons in controlling action selection among sex, fight, feeding, and sleep behaviors in both sexes of flies. We also discuss potentially conserved circuit configurations and neuromodulation of action selection in both the fly and mouse models, aiming to provide insights into action selection and the sexually dimorphic prioritization of innate behaviors.
Animals ; Mice ; Male ; Female ; Drosophila melanogaster/physiology* ; Sexual Behavior, Animal/physiology* ; Instinct ; Neurons/physiology* ; Aggression/physiology*

Females increase aggression for mating opportunities and for acquiring reproductive resources. Although the close relationship between female aggression and mating status is widely appreciated, whether and how female aggression is regulated by mating-related cues remains poorly understood. Here we report an interesting observation that Drosophila virgin females initiate high-frequency attacks toward mated females. We identify 11-cis-vaccenyl acetate (cVA), a male-derived pheromone transferred to females during mating, which promotes virgin female aggression. We subsequently reveal a cVA-responsive neural circuit consisting of four orders of neurons, including Or67d, DA1, aSP-g, and pC1 neurons, that mediate cVA-induced virgin female aggression. We also determine that aSP-g neurons release acetylcholine (ACh) to excite pC1 neurons via the nicotinic ACh receptor nAChRα7. Together, beyond revealing cVA as a mating-related inducer of virgin female aggression, our results identify a neural circuit linking the chemosensory perception of mating-related cues to aggressive behavior in Drosophila females.
Animals ; Male ; Female ; Drosophila/physiology* ; Drosophila Proteins/physiology* ; Cues ; Sexual Behavior, Animal/physiology* ; Aggression/physiology* ; Drosophila melanogaster/physiology*

Acrylamide is a common chemical material, extensively used in industry and scientific experiments. Recently, it has been reported that starchy food cooked at high temperature can produce acrylamide. Acrylamide monomer has several toxic effects and the extensive concern for its toxicity has arisen with the finding of acrylamide formation in some processed foods. Researches have shown that acrylamide monomer can cause reproductive toxicity, including toxic effects on male reproductive behavior, male reproductive endocrine function and spermatogenesis. The mechanisms may include the effects of acrylamide on Leydig cells, the formation of motor protein/ chromosomal/DNA alkylation and damage by oxidative stress.
Acrylamide ; toxicity ; Animals ; Genitalia, Male ; drug effects ; physiology ; Male ; Sexual Behavior, Animal ; drug effects ; physiology ; Spermatogenesis ; drug effects

Animal models in sexual dysfunction were reviewed to further improve the modeling methods and to promote the effectiveness of drug evaluation translation from animal models to humans. A MEDLINE search was performed to retrieve articles relating to animal models in sexual dysfunction. Researches on a variety of animal models in sexual dysfunction, with their own merits, has to a certain extent contributed to the understanding of sexual function. However, no models could give a fully accurate assessment of sexual function. The existing sexual function studies on animal models of interpretive function, the development mechanisms, the effects of drugs on sexual function and the clinical translation still have some deficiencies, but with their basic principles and ideas for the improvement of the models and the preservation of the valuable data of drugs and clinical trials.
Animals ; Disease Models, Animal ; Drug Design ; Female ; Humans ; Male ; Rats ; Sexual Behavior, Animal ; drug effects ; physiology ; Sexual Dysfunction, Physiological ; drug therapy ; physiopathology

OBJECTIVETo investigate the effects of alcohol intake on penile structure and function in rats.

METHODSThirty adult male Wistar rats were randomly divided into two groups: control group and alcohol intake group. They were administered with 2 mL of normal saline and 40% alcohol solution respectively through gastric tubes every day. Three months later, the animal model of alcohol intake was evaluated by modified Nayagida's method, and the effects of alcohol on the rats were studied by sexual behavior, the number of apomorphine-induced penile erection, level of testosterone in the sera, and the content of penile smooth muscle.

RESULTSThe scores of animal model of alcohol intake evaluated by Nayagida's method were 0.66 +/- 2.05 in the control group and 9.26 +/- 5.50 in the alcohol intake group (P < 0.05), which indicated that an animal model of alcohol intake was successfully established. Sexual behavior, the number of apomorphine-induced penile erection, testosterone level in the sera, and the content of penile smooth muscle of the alcohol intake group were all statistically different as compared with the control group (P < 0.05).

CONCLUSIONAlcohol intake induces sexual dysfunction in rats, which may be due to the decline of testosterone level in the sera and decline of penile smooth muscle.

Animals ; Ethanol ; adverse effects ; Female ; Male ; Penis ; anatomy & histology ; drug effects ; physiology ; Rats ; Rats, Wistar ; Sexual Behavior, Animal ; Testosterone ; blood

The choice of females to accept or reject male courtship is a critical decision for animal reproduction. Serotonin (5-hydroxytryptamine; 5-HT) has been found to regulate sexual behavior in many species, but it is unclear how 5-HT and its receptors function to regulate different aspects of sexual behavior. Here we used Drosophila melanogaster as the model animal to investigate how 5-HT and its receptors modulate female sexual receptivity. We found that knockout of tryptophan hydroxylase (Trh), which is involved in the biosynthesis of 5-HT, severely reduced virgin female receptivity without affecting post-mating behaviors. We identified a subset of sexually dimorphic Trh neurons that co-expressed fruitless (fru), in which the activity was correlated with sexual receptivity in females. We also found that 5-HT_1A and 5-HT₇ receptors regulate virgin female receptivity. Our findings demonstrate how 5-HT functions in sexually dimorphic neurons to promote virgin female receptivity through two of its receptors.
Animals ; Male ; Female ; Drosophila/physiology* ; Drosophila melanogaster/physiology* ; Serotonin ; Drosophila Proteins/physiology* ; Sexual Behavior, Animal/physiology* ; Transcription Factors ; Nerve Tissue Proteins

OBJECTIVETo investigate the effects of hypoxia during the prenatal period and its later repercussions on sexual behavior and the sex hormone secretion of male rats.

METHODSExperimental animals were divided into three groups randomly: control group, which was kept at normal atmospheric pressure, and two stress groups exposed to a simulated altitude equivalent to 3000 m and 5000 m, respectively. Stress groups were exposed to hypoxic circumstance at their final week of gestation in animal decompression chamber.

RESULTSAdulthood, males exposed to hypoxic stress during the prenatal period were able to mate with normal females, but these treated males exhibited decreased male sexual behavior. Decreased anogenital distances were observed in male offspring, and presented reductions of plasma testosterone levels, increase of plasma corticosterone levels, but no notable alteration in the organ index.

CONCLUSIONThese results indicate that exposure to hypoxia in the later stages of pregnancy may have a long-term effect on the fertility and sexual behavior of male offspring.

Animals ; Female ; Hypoxia ; physiopathology ; Male ; Pregnancy ; Prenatal Exposure Delayed Effects ; Rats ; Rats, Sprague-Dawley ; Sexual Behavior, Animal ; physiology ; Stress, Physiological ; physiology ; Testosterone ; blood

Differences in intravaginal ejaculation latency reflect normal biological variation, but the causes are poorly understood. Here, we investigated whether variation in ejaculation latency in an experimental rat model is related to altered sympathetic nervous system (SNS) activity and expression of N-methyl-D-aspartic acid (NMDA) receptors in the paraventricular nucleus of the hypothalamus (PVN). Male rats were classified as "sluggish," "normal," and "rapid" ejaculators on the basis of ejaculation frequency during copulatory behavioral testing. The lumbar splanchnic nerve activity baselines in these groups were not significantly different at 1460 ± 480 mV, 1660 ± 600 mV, and 1680 ± 490 mV, respectively (P = 0.71). However, SNS sensitivity was remarkably different between the groups (P < 0.01), being 28.9% ± 8.1% in "sluggish," 48.4% ± 7.5% in "normal," and 88.7% ± 7.4% in "rapid" groups. Compared with "normal" ejaculators, the percentage of neurons expressing NMDA receptors in the PVN of "rapid" ejaculators was significantly higher, whereas it was significantly lower in "sluggish" ejaculators (P = 0.01). In addition, there was a positive correlation between the expression of NMDA receptors in the PVN and SNS sensitivity (r = 0.876, P = 0.02). This study shows that intravaginal ejaculatory latency is associated with SNS activity and is mediated by NMDA receptors in the PVN.
Animals ; Copulation ; Ejaculation/physiology* ; Female ; Male ; Neurons/physiology* ; Paraventricular Hypothalamic Nucleus/physiology* ; Rats ; Rats, Sprague-Dawley ; Receptors, N-Methyl-D-Aspartate/metabolism* ; Sexual Behavior, Animal/physiology* ; Splanchnic Nerves/physiology* ; Sympathetic Nervous System/physiology*

OBJECTIVETo observe the effects of Fructus Corni polysaccharides (FCP) on sexual function of hemicastrated rats.

METHOD70 male SD rats are randomly divided into 7 groups with their right testis extirpated except for normal control group. Normal control group and negative control group are given saline (ig) while positive control group are injected hypodermically testosterone propionate at dose of 2 mg x kg(-1) x d(-1). FCP control groups are given FCP separately at dose of 10, 50, 100, 150 mg x kg(-1) x d(-1) (ig). Mating test and erective test are observed. The levels of serum sex hormone T, LSH, FSH, E2 are detected with the Radioimmunoassay (RIA).

RESULTIncubation period of penis erection and mounting are shortened in FCP control groups and positive control group, and the percentage of mounting rats is increased. The level of serum sex hormone T is increased, but estradiol level is reduced. The organ coefficient of foreskin gland and seminal vesicle-prostate gland as well as sperm count and vigor are increased significantly (P < 0.01 or P < 0.05).

CONCLUSIONFCP can increase the sexual function of hemicastrated rats. The mechanism is probably through adjustment of the hypothalamus-pituitary-gonadal axis.

Animals ; Cornus ; chemistry ; Female ; Male ; Penile Erection ; drug effects ; Polysaccharides ; pharmacology ; toxicity ; Rats ; Rats, Sprague-Dawley ; Sexual Behavior, Animal ; drug effects ; Sexual Dysfunction, Physiological ; chemically induced ; Testis ; drug effects ; physiology

OBJECTIVETo investigate the effects of kidney-jing deficiency on the fertility of male mice and their male offspring.

METHODSThirty 6-week-old Kunming male mice and 300 female ones were randomly allocated to a blank control group, a model group and a kidney-tonifying group. The model and the kidney-tonifying groups were stressed by fear plus excessive sex to establish a kidney-jing deficiency model, and meanwhile the latter were given concentrated solution of Kidney-tonifying Recipe intragastrically at the dose of 0.16 ml/10 g. The control and the model groups were treated with physiological saline at the same dose for 21 days. Then all the male mice were mated with the healthy estrous females for 5 days. The sperm density and motility of each group of the male mice were examined, and their fertility was assessed by comparison of the pregnancy rate and the number of baby mice at each birth among their female mates. And the sperm density and motility of the male offspring were detected at 6 weeks.

RESULTSThe average number of baby mice at each birth in the model group was (7.00 +/- 1.73), significantly smaller than those in the control (9.43 +/- 1.27) and the kidney-tonifying group (8.80 +/- 1.10) (P < 0.05). The sperm density and motility of the model mice were (9.70 +/- 1.15) x 10(6) / ml and (66.72 +/- 10. 12) %, lower than those of the control ([14.08 +/- 1.15 x 10(6)/ ml and [81.75 +/- 3.56] %), and the kidney-tonifying group ([12.20 +/- 1.55] x 10(6)/ ml and [78.55 +/- 4.38] %) (P < 0.05). There was no significant difference between the latter two groups (P > 0.05). The sperm density and motility of the offspring of the model mice were (10.10 +/- 1.79) x 10(6)/ ml and (71.86 +/- 7.48) %, lower than those of the control ([15.30 +/- 1.83] x 10(6)/ ml and [79.86 +/- 5.68] %), and the kidney-tonifying group ([14.20 +/- 2.21] x 10(6)/ ml and [81.92 +/- 2.51] %) (P < 0.05), with no significant difference between the latter two groups (P > 0.05).

CONCLUSIONFear plus excessive sex could reduce the fertility of male mice and even that of their male offspring. And kidney-tonifying therapy could counteract this effect.

Animals ; Animals, Newborn ; Cats ; Disease Models, Animal ; Fear ; psychology ; Female ; Fertility ; drug effects ; physiology ; Litter Size ; drug effects ; Male ; Materia Medica ; pharmacology ; Mice ; Predatory Behavior ; physiology ; Random Allocation ; Sexual Behavior, Animal ; drug effects ; Sperm Count ; Sperm Motility ; drug effects ; Stress, Psychological ; physiopathology