Centre de Recherche Fernand-Seguin, Department of Psychiatry, University of Montreal, Montréal, Québec, Canada.
Behav Brain Res. 2009 Dec 14;205(1):115-22. doi: 10.1016/j.bbr.2009.07.023. Epub 2009 Jul 28.
A growing body of literature suggests that sex differences exist in both rodents and humans in terms of the central processing of stress and emotion, and an important factor in this regard may involve differential hemispheric specialization. The amygdala has been shown to be functionally asymmetrical in both rats and humans and its involvement in stress and emotion processing is well documented. Given that amygdala function is importantly modulated by dopamine (DA), the present study examined the effects of left vs. right unilateral DAergic depletion targeting the basolateral amygdala in male and female rats. We examined behaviour in the elevated plus maze over two consecutive days, and plasma adrenocorticotropic hormone (ACTH) levels in response to a separate 30min restraint stress. Overall, females showed significantly more exploration of open arms of the plus maze than males, while not differing in general activity reflected in closed arm entries. Significant SexxHemisphere interactions were observed for all measures related to open arm exploration, as right amygdala DA depletion produced an anxiolytic effect in males, increasing open arm exploration, but reduced this behaviour in females. Moreover, open arm exploration was greatly reduced on the second maze exposure in males, but unchanged in females. A SexxHemisphere interaction was also found for plasma ACTH levels. It is suggested that the role of amygdala DA on stress-related behaviour and physiology reflects inherent differences in amygdala function dependent on both sex and hemisphere.
越来越多的文献表明，在啮齿动物和人类中，压力和情绪的中枢处理存在性别差异，而这方面的一个重要因素可能涉及到半球的差异特化。杏仁核在大鼠和人类中均表现出功能上的不对称性，其在压力和情绪处理中的作用已有充分的文献记载。鉴于杏仁核功能受到多巴胺（DA）的重要调节，本研究检查了针对雄性和雌性大鼠基底外侧杏仁核的左侧和右侧单侧 DA 能耗竭对其的影响。我们在连续两天的高架十字迷宫实验中检查了行为，并用 30 分钟的单独束缚应激来检测血浆促肾上腺皮质激素（ACTH）水平。总的来说，雌性大鼠比雄性大鼠表现出明显更多的开放臂探索，而在封闭臂进入所反映的一般活动中没有差异。与开放臂探索相关的所有测量值都观察到显著的性别x半球相互作用，因为右侧杏仁核 DA 耗竭在雄性大鼠中产生了抗焦虑作用，增加了开放臂探索，但在雌性大鼠中则减少了这种行为。此外，雄性大鼠在第二次迷宫暴露时的开放臂探索大大减少，但雌性大鼠则没有变化。在血浆 ACTH 水平上也发现了性别x半球的相互作用。因此，杏仁核 DA 在应激相关行为和生理学中的作用反映了依赖于性别和半球的杏仁核功能的固有差异。
