Stress and Sex Effects on Learning and Dendritic Spines

我们实验室的大量实验表明，暴露在急性应激经历中会促进雄性大鼠的联想学习，并显著损害雌性大鼠的学习能力。我们还发现了性别差异和压力对男性和女性海马区树突棘密度的相反影响。在男性中，暴露于急性应激源后，脊椎密度会增加，而女性的树突密度会降低。在这一系列观察的基础上，我们提出了应激对学习的影响是通过对脊柱密度的应激效应来调节的。为了解决这一假设，我将测试压力对男性收入的相反影响是否与女性相反。在男性中，压力诱导的学习促进依赖于与压力相关的肾上腺激素，即糖皮质激素。女性应激性学习障碍不依赖于应激相关的糖皮质激素，而依赖于卵巢激素雌激素。因此，我的建议的目标是确定男性中的糖皮质激素和女性中的雌激素是否导致树突棘密度的性对立压力。

Numerous experiments in our laboratory have shown that exposure to an acute stressful experience facilitates associative learning in male rats and dramatically impairs learning in female rats. We have also found sex differences and opposing effects of stress on dendritic spine density in the hippocampus of males versus females. In males, spine density is enhanced after exposure to an acute stressor, while the density of dendritic spines in females is reduced. Based on this series of observations, we have proposed that the stress effects on learning are mediated by the stress effects on spine density. To address this hypothesis, I will test whether the opposite effects of stress on earning in males versus females. In males, the stress-induced facilitation of learning is dependent on the stress-related adrenal hormones, glucocorticoids. The stress-induced impairment of learning in females is not dependent on the stress-related glucocorticoids, but is dependent on the ovarian hormone estrogen. Thus, the goal of my proposal is to determine whether glucocorticoids in males and estrogen in females contribute to the sexually opposed stress on dendritic spine density.