Dalla C, Antoniou K, Papadopoulou-Daifoti Z, Balthazart J, Bakker J
Center for Cellular and Molecular Neurobiology, University of Liège, Belgium.
Behav Brain Res. 2005 Sep 8;163(2):186-93. doi: 10.1016/j.bbr.2005.04.020.
It is well known that estradiol derived from neural aromatization of testosterone plays a crucial role in the development of the male brain and the display of sexual behaviors in adulthood. It was recently found that male aromatase knockout mice (ArKO) deficient in estradiol due to a mutation in the aromatase gene have general deficits in coital behavior and are sexually less motivated. We wondered whether these behavioral deficits of ArKO males could be related to changes in activity, exploration, anxiety and "depressive-like" symptomatology. ArKO and wild type (WT) males were subjected to open field (OF), elevated plus maze (EPM), and forced swim tests (FST), after being exposed or not to chronic mild stress (CMS). CMS was used to evaluate the impact of chronic stressful procedures and to unveil possible differences between genotypes. There was no effect of genotype on OF, EPM and FST behavioral parameters. WT and ArKO mice exposed to CMS or not exhibited the same behavioral profile during these three types of tests. However, all CMS-exposed mice (ArKO and WT) spent less time in the center of the EPM. Additionally, floating duration measured in the FST increased between two tests in both WT and ArKO mice, though that increase was less prominent in mice previously subjected to CMS than in controls. Therefore, both ArKO and WT males displayed the same behavior and had the same response to CMS however CMS exposure slightly modified the behavior displayed by mice of both genotypes in the FST and EPM paradigms. These results show that ArKO males display normal levels of activity, exploration, anxiety and "depressive-like" symptomatology and thus their deficits in sexual behavior are specific in nature and do not result indirectly from other behavioral changes.
众所周知，睾酮经神经芳香化作用产生的雌二醇在雄性大脑发育及成年期性行为表现中发挥着关键作用。最近发现，由于芳香化酶基因突变而缺乏雌二醇的雄性芳香化酶基因敲除小鼠（ArKO）在交配行为方面存在普遍缺陷，且性动机较低。我们想知道ArKO雄性小鼠的这些行为缺陷是否与活动、探索、焦虑及“类抑郁”症状的变化有关。在暴露或未暴露于慢性轻度应激（CMS）后，对ArKO和野生型（WT）雄性小鼠进行旷场试验（OF）、高架十字迷宫试验（EPM）和强迫游泳试验（FST）。CMS用于评估慢性应激程序的影响，并揭示不同基因型之间可能存在的差异。基因型对OF、EPM和FST行为参数没有影响。暴露或未暴露于CMS的WT和ArKO小鼠在这三种类型的试验中表现出相同的行为特征。然而，所有暴露于CMS的小鼠（ArKO和WT）在EPM中央区域停留的时间都较短。此外，在FST中测量的漂浮持续时间在WT和ArKO小鼠的两次试验之间均有所增加，不过，先前接受CMS处理的小鼠的增加幅度不如对照组明显。因此，ArKO和WT雄性小鼠表现出相同的行为，对CMS的反应也相同，然而，CMS暴露略微改变了两种基因型小鼠在FST和EPM范式中表现出的行为。这些结果表明，ArKO雄性小鼠的活动、探索、焦虑及“类抑郁”症状水平正常，因此它们的性行为缺陷本质上是特异性的，并非由其他行为变化间接导致。
