Role of central neurons system in hypothalamus on regulation of copulatory behavior in male rats.

本实验测定了雄性大鼠性活动过程中视前内侧区（MPOA）细胞外多巴胺（DA）和乙酰胆碱（Ach）的浓度。交配过程中，MPOA中DA和Ach的含量显著增加。由于给药导致的DA升高促进了大鼠的雄性交配行为。这些研究结果是一致的断言，在MPOA的DA神经元活动促进男性copulatory behavior.We研究了长期的心理应激对大鼠的性行为和脑中的儿茶酚胺的影响。结果表明，长期心理应激对雄性大鼠的性行为有损害作用。长期心理应激使脑内儿茶酚胺及其代谢产物含量降低，尤其是内侧视前区（MPOA）。因此，我们假设大脑中的低儿茶酚胺神经传递导致雄性大鼠的性行为受损，然后我们试图通过给药大脑激活药物盐酸吲哚洛嗪来恢复受损的性行为。给药3周的盐酸吲哚洛嗪可以恢复因长期心理应激而受损的性行为。此外，我们还研究了睾酮替代品对老年雄性大鼠交配行为的影响。睾酮替代可恢复老年雄性大鼠的交配行为和DA能神经元的活性，提示性功能障碍的病因的消除和神经递质的激活可使受损的雄性性行为得以恢复。

We measured the extracellular concentrations of dopamine (DA) and acethylcholine (Ach) in the medial preoptic area (MPOA) of rats during male sexual activity. During copulation, the concentration of DA and Ach in the MPOA was significantly increased. Elevation of DA due to the drug administration facilitated male copulatory behavior in rats. These findings were consistent with the assertion that DA neuron activity in the MPOA facilitates male copulatory behavior.We investigated the effects of long-term psychological stress on sexual behavior and brain catecholamines in rats. The results showed that long-term psychological stress impaired the sexual behavior of male rats. Long-term psychological stress decreased the concentrations of catecholamine and its metabolites in the brain, especially in the medial preoptic area (MPOA). Thus, we hypothesized thet low catecholamine neurotransmission in the brain results in impairment of male rat sexual behavior.We then tried to restore the impaired sexual behavior by administration of a cerebral-activating drug, indeloxazine hydrochloride. The administration of indeloxazine hydrochloride for a 3-week period restored the sexual behavior that had been impaired by long-term psychological stress.Furthermore, we investigated the effects of testosterone replacements on copulatory behavior of aged male rats. Testosterone replacement restored the copulatory behavior and DA neuron activity of aged male rats.These present results suggest that impairment of cause of sexual dysfunction, and activation of neurotransmission may result in restoration of impaired male sexual behavior.