Departamento de Farmacobiologia, Cinvestav Sede Sur, Calzada de los Tenorios 235, Col. Granjas Coapa, Ciudad de México, 14330, México.
Psychopharmacology (Berl). 2019 Apr;236(4):1303-1312. doi: 10.1007/s00213-018-5142-y. Epub 2018 Dec 8.
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.
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.
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.
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.
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.
控制交配的主要多巴胺脑区，即内侧视前区（mPOA）和伏隔核（NAcc），对雄性大鼠性行为表达的影响尚未完全确定。
本研究分析了在有性动机（性活跃）或性动机降低（性疲劳）的雄性大鼠的 mPOA 或 NAcc 中激活多巴胺（DA）受体对其性行为的影响。
将非特异性 DA 受体激动剂阿扑吗啡和 D2 样受体激动剂喹吡罗注入性活跃或性疲劳雄性大鼠的 mPOA 或 NAcc，并记录其性行为。
无论是在 mPOA 还是在 NAcc 中激活 DA 受体，都不能改变性活跃雄性大鼠的交配行为。DA 受体在 NAcc 中的刺激，而不是在 mPOA 中，逆转了性满足大鼠的特征性性抑制，并且发现 D2 样受体参与了这种作用。
在这两个脑区，DA 受体的激活都不能进一步提高性活跃雄性大鼠的最佳性表现。在性疲劳的大鼠中，由于性抑制和性动机降低，NAcc 的 DA 受体刺激似乎在它们对具有重要动机的刺激——接受性雌性的反应能力中发挥关键作用，并且 D2 样受体参与了这一作用。用相同的药物、相同的剂量和相同的脑区激活 DA 受体，对交配行为产生不同的影响，这取决于动物的性动机状态。
