Sex differences in fetal programming by glucocorticoids: Adult hypothalamus and Autonomic Nervous System

项目摘要/摘要 这个项目的首要目标和最终影响是确定细胞和生理途径 由此，发育过度暴露于糖皮质激素导致成人的长期、性别选择性编程 焦虑和抑郁样行为、神经内分泌功能和自主神经系统反应 压力。发育规划，胎儿对母体环境信号的永久适应 可以提高胎儿糖皮质激素水平以规划神经发育。小鼠和大鼠的初步数据显示性别- 妊娠晚期接触合成糖皮质激素地塞米松后的偏向变化。这些 包括焦虑和抑郁样行为增加，以及神经内分泌和自主神经过度反应 神经系统对压力的反应和下丘脑基因表达的变化。在所有情况下，成人 女性比男性表现出更大的变化。我们假设这些成人功能障碍有一个共同的 与下丘脑室旁核(PVN)程序性变化有关的机制 已经被证明会影响所有这些生理终点。我们的研究表明，这两个人的反应相似 大鼠和小鼠，使得这些研究能够充分利用大鼠的生理学以及 老鼠的遗传方法。描述了3个具体目标。目标1将确定长期- 焦虑和抑郁样行为、神经内分泌对压力的反应和失衡的术语变化 自主神经系统的一部分。此外，这一目标将研究中枢肾素-血管紧张素系统作为 胎儿期糖皮质激素过度暴露后脑功能变化的中枢调节因子。 目的2将确定产前接触糖皮质激素对下丘脑之间连接的影响 自主前核和脑干自主核，并使用小鼠遗传方法和病毒载体 特异性地激活下丘脑室旁核中的神经元群体。目标3将使用经皮迷走神经刺激 调节自主神经系统平衡和逆转产前糖皮质激素暴露对 成人行为、神经内分泌和自主神经对压力的反应。这些研究的结果将确定， 不仅是行为、内分泌和性别偏见的发育规划背后的大脑回路 成年期的自主神经反应，但也揭示了这些变化的潜在治疗机制 可以在成年后逆转。

PROJECT SUMMARY / ABSTRACT The overarching goal, and ultimate impact, of this project is to identify the cellular and physiological pathways whereby developmental overexposure to glucocorticoids cause long-term, sex-selective programming of adult anxiety- and depressive-like behaviors, neuroendocrine function and autonomic nervous system responses to stress. Developmental programming, the permanent adaptation of the fetus to maternal environmental signals can elevate fetal glucocorticoids to program neurodevelopment. Preliminary data in mice and rats show sex- biased changes following late-gestation exposure to the synthetic glucocorticoid, dexamethasone. These include increased anxiety- and depressive-like behaviors, and hyperreactive neuroendocrine and autonomic nervous system responses to stress and changes in gene expression in the hypothalamus. In all cases, adult females showing a greater change than males. We hypothesize that these adult dysfunctions have a common mechanism related to programmed changes in the hypothalamic paraventricular n. (PVN), a brain region that has been shown to influence all of these physiological endpoints. Our studies show similar responses in both rats and mice allowing these studies to exploit the well-described physiology of the rat as well as the power of mouse genetic approaches. 3 specific aims are described. Aim 1 will determine the causal factors for long- term alterations in anxiety-and depressive-like behaviors, neuroendocrine response to stress and an imbalance of the autonomic nervous system. Moreover, this aim will examine the central renin-angiotensin system as a central mediator of the observed changes in brain function following prenatal glucocorticoid overexposure. Aim 2 will determine the impact of prenatal glucocorticoid exposure on connectivity between hypothalamic preautonomic and brainstem autonomic nuclei and use mouse genetic approaches and viral vectors to specifically activate neuron populations in the PVN. Aim 3 will use transcutaneous vagal nerve stimulation to modulate autonomic nervous system balance and reverse the effects of prenatal glucocorticoid exposure on adult behaviors, neuroendocrine, and autonomic responses to stress. The results of these studies will identify, not only the brain circuitry underlying the sex-biased developmental programming of behavioral, endocrine and autonomic responses in adulthood, but also reveal potential therapeutic mechanisms whereby these changes can be reversed in adulthood.