Matuszewich L, Dornan W A
Department of Psychology, Illinois Wesleyan University, Bloomington 61701.
Psychopharmacology (Berl). 1992;106(3):391-6. doi: 10.1007/BF02245424.
We examined the putative functional role of the medial preoptic nucleus mu-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 selective mu-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 by mu receptors located within the medial preoptic nucleus.
我们研究了内侧视前核μ受体群体在性活跃的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，与注射生理盐水的对照组相比，向内侧视前核双侧注射三种剂量的吗啡肽（10、500和1000纳克），一种选择性μ受体激动剂，会使雄性交配行为的启动明显延迟。这些注射显著延长了插入和骑跨潜伏期，而对雄性交配行为的任何其他参数没有明显影响。在另一个实验中，在向内侧视前核双侧注射吗啡肽（1000纳克）前20分钟预先用纳洛酮处理后，雄性交配行为表达的短暂抑制被完全消除。总体而言，这些结果表明，外周或中枢注射阿片类药物后通常观察到的交配启动延迟至少部分是由内侧视前核内的μ受体介导的。
