Bilateral injections of a selectiveμ-receptor agonist (morphiceptin) into the medial preoptic nucleus produces a marked delay in the initiation of sexual behavior in the male rat
Bilateral injections of a selectiveμ-receptor agonist (morphiceptin) into the medial preoptic nucleus produces a marked delay in the initiation of sexual behavior in the male rat
复制标题
向内侧视前核双侧注射选择性 μ 受体激动剂（吗啡肽）可显着延迟雄性大鼠性行为的开始
作者：
L. Matuszewich;W. Dornan
我们研究了内侧视前核μ受体群体在性欲旺盛的Long-Evans大鼠雄性交配行为表达中的假定功能作用。在第一个实验中，将选择性μ受体激动剂吗啡肽(10,500和1000 ng)注射到双侧视前内侧核，与注射生理盐水的对照组相比，雄性交配行为的开始明显延迟。这些注射显著延长了插入潜伏期和坐骑潜伏期，而对雄性交配行为的任何其他参数没有明显影响。在另一项单独的实验中，在双侧视前内侧核注射吗啡(1000 Ng)前20分钟，纳洛酮预处理完全取消了对雄性交配行为表达的短暂抑制。总之，这些结果表明，在外周或中央注射阿片类药物后，通常观察到的交配开始延迟至少部分是由位于视前内侧核的μ受体介导的。
We examined the putative functional role of the medial preoptic nucleusμ-receptor population in the expression of male copulatory behavior in sexually vigorous Long-Evans rats. In the first experiment, three doses of morphiceptin (10, 500, and 1000 ng) a selectiveμ-receptor agonist injected bilaterally into the medial preoptic nucleus, produced a marked delay in the initiation of male copulatory behavior compared to saline injected controls. These injections significantly lengthened intromission and mount latencies while having no appreciable effect on any other parameter of male copulatory behavior. In a separate experiment, the transient inhibition of the expression of male copulatory behavior was completely abolished following pretreatment of naloxone 20 minutes prior to bilateral injections of morphiceptin (1000 ng) into the medial preoptic nucleus. Collectively, these results suggest that the delay in the initiation of copulation that is commonly observed following peripheral or central injections of opioids is mediated at least in part byμ receptors located within the medial preoptic nucleus.