Shishkina G T, Kalinina T S, Sournina N Y, Dygalo N N
Institute of Cytology and Genetics, Russian Academy of Sciences, Novosibirsk 630090, Russia.
J Neurosci. 2001 Jan 15;21(2):726-31. doi: 10.1523/JNEUROSCI.21-02-00726.2001.
Clinical and experimental findings have implicated brain alpha2-adrenoceptors in the regulation of many physiological functions, including sexual activity and stress-related behavior. However, which subtypes of the three alpha2-adrenoceptors that have now been cloned (alpha2A, alpha2B, and alpha2C) are involved in these controls have yet to be established. Here, we investigated the contribution of alpha2A-adrenoceptors of the locus ceruleus, the principal source of brain noradrenaline, to exploratory and sexual behaviors. Using administration of antisense oligodeoxynucleotide to inhibit the receptor expression, we found that reductions in brainstem alpha2A-adrenoceptor mRNA levels and alpha2-adrenoceptor densities induced by antisense treatment were not accompanied by any changes in the major characteristics of male sexual activity, such as mount latencies and numbers of mounts. However, in sexual behavior tests, antisense-treated male rats had decreased numbers of rearings and thus have higher percentages of behaviors positively correlated with sexual activity. Besides, antisense-treated animals had decreased anxiety in plus-maze tests. The data demonstrate that inhibition of alpha2A-adrenoceptor expression in the region of the locus ceruleus has an anxiolytic-like effect and facilitates male's attention to female in sexual behavior test.
临床和实验研究结果表明，脑内α2肾上腺素能受体参与调节包括性活动和应激相关行为在内的多种生理功能。然而，目前已克隆出的三种α2肾上腺素能受体亚型（α2A、α2B和α2C）中，哪些参与这些调控作用尚未明确。在此，我们研究了脑内去甲肾上腺素的主要来源——蓝斑核中的α2A肾上腺素能受体对探索行为和性行为的作用。通过给予反义寡脱氧核苷酸抑制受体表达，我们发现反义处理诱导的脑干α2A肾上腺素能受体mRNA水平和α2肾上腺素能受体密度降低，并未伴随雄性性活动主要特征的任何变化，如爬上潜伏期和爬上次数。然而，在性行为测试中，反义处理的雄性大鼠的后肢站立次数减少，因此与性活动呈正相关的行为百分比更高。此外，反义处理的动物在加迷宫测试中的焦虑程度降低。这些数据表明，抑制蓝斑核区域的α2A肾上腺素能受体表达具有抗焦虑样作用，并在性行为测试中促进雄性对雌性的关注。
