Sex differences in the basolateral amygdala: the extracellular levels of serotonin and dopamine, and their responses to restraint stress in rats
Sex differences in the basolateral amygdala: the extracellular levels of serotonin and dopamine, and their responses to restraint stress in rats
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DOI：
10.1111/j.1460-9568.2006.05214.x
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发表时间：
2006-12-01
影响因子：
3.4
通讯作者：
Kimura, Fukuko
中科院分区：
文献类型：
--
作者：
Mitsushima, Dai;Yamada, Kaori;Kimura, Fukuko
对压力的情绪反应的性别差异表明杏仁核存在性别特异性的压力反应。为探讨杏仁基底外侧核(BLA)细胞外5-羟色胺(5-羟色胺)和多巴胺(DA)水平的性别差异及其对束缚应激的反应，对雄性和雌性大鼠进行了体内微透析研究。在实验I中，在自由移动的条件下，每隔15分钟从BLA收集透析液。雄性大鼠外周血中5-羟色胺和多巴胺的平均胞外水平高于雌性大鼠。实验二采用束缚应激60min，观察大鼠对5-羟色胺和多巴胺的应激反应。尽管束缚应激显著增加了两性大鼠的细胞外5-羟色胺水平，但雌性大鼠的反应比雄性大鼠更大。此外，束缚应激显著增加雌性大鼠的细胞外多巴胺水平，但对雄性大鼠无明显影响。在实验三中，大鼠受到束缚应激30min，以检测对束缚应激的行为反应。虽然在可听发声的数量上没有性别差异，但雄性大鼠比雌性大鼠排出更多的粪便颗粒。在实验四中，对大鼠的冻结行为进行了测试，以检查背景恐惧反应。条件性雄性大鼠比条件性雌性大鼠有更长的冷冻时间。我们发现BLA中5-羟色胺和多巴胺的胞外水平以及它们对束缚应激的反应存在性别差异，这可能与大鼠对应激的性别特异性情绪反应有关。
The sex difference in the emotional response to stress suggests a sex-specific stress response in the amygdala. To examine the sex difference in extracellular levels of serotonin (5HT) and dopamine (DA) in the basolateral amygdala (BLA) and their responses to restraint stress, in vivo microdialysis studies were performed in male and female rats. In experiment I, dialysates were collected from the BLA at 15-min intervals under the freely moving condition. Mean extracellular levels of 5HT or DA in the BLA were higher in male rats than in female rats. In experiment II, rats were subjected to restraint stress for 60 min to examine the stress response of 5HT or DA levels. Although restraint stress significantly increased extracellular 5HT levels in both sexes of rats, female rats showed a greater response than male rats. Moreover, restraint stress significantly increased extracellular DA levels in female rats, but not in male rats. In experiment III, rats were subjected to restraint stress for 30 min to examine behavioral responses to restraint stress. Although no sex difference was observed in the number of audible vocalizations, male rats defecated a larger number of fecal pellets than female rats. In experiment IV, rats were tested for freezing behavior to examine contextual fear responses. Conditioned male rats showed a longer freezing time than conditioned female rats. We found sex differences in the extracellular levels of 5HT and DA in the BLA and their responses to restraint stress, which may be involved in the sex-specific emotional response to stress in rats.