رفتار جنسی در جوندگان نر

The hormonal factors and neural circuitry that control copulation are similar across rodent species, although there are differences in specific behavior patterns. Both estradiol (E) and dihydrotestosterone (DHT) contribute to the activation of mating, although E is more important for copulation and DHT for genital reflexes. Hormonal activation of the medial preoptic area (MPOA) is most effective, although implants in the medial amygdala (MeA) can also stimulate mounting in castrates. Chemosensory inputs from the main and accessory olfactory systems are the most important stimuli for mating in rodents, especially in hamsters, although genitosensory input also contributes. Dopamine agonists facilitate sexual behavior, and serotonin (5-HT) is generally inhibitory, though certain 5-HT receptor subtypes facilitate erection or ejaculation. Norepinephrine agonists and opiates have dose-dependent effects, with low doses facilitating and high doses inhibiting behavior.

Reproductive behaviors and their neural and hormonal regulation vary widely across species. Yet much research has focused on relatively few animals. We describe the behaviors of male rodents and their neural, hormonal, and experiential regulation. We begin with rats, the most common subjects of laboratory research. We then describe the behaviors of male mice, hamsters, and guinea pigs, noting similarities and differences among species. Sexual behavior is highly interactive; here we concentrate on the male, keeping in mind that the contributions of the female are equally important. Because of the vast amount of research on rodents, and the page limits for this manuscript, we can cite only a small portion of it. For additional details, please consult Hull et al. (2006) or Hull et al. (2002).

Although there are differences in the copulatory elements among rodents, the hormonal factors and neural circuitry that control those elements are similar. Both E and DHT contribute to the activation of mating, although E is more important for copulation, and DHT, for genital reflexes of rats, mice, and hamsters. Hormonal activation of the MPOA is most effective, although implants in the MeA can also stimulate mounting in castrates. Chemosensory inputs from the main and accessory olfactory systems are the most important stimuli for mating, especially in hamsters, although genitosensory input via the SPFp also contributes. DA agonists facilitate sexual behavior when injected either systemically or into the MPOA or PVN. 5-HT agonists, especially 5-HT1B, tend to inhibit behavior, although 5-HT2C agonists facilitate erection and 5-HT1A agonists facilitate ejaculation (except in mice). Norepinephrine agonists and opiates have dose-dependent effects, with low doses facilitating and high doses inhibiting behavior.