Oxytocin regulates stress response and anxiety through functional modulation of amygdala

催产素是一种多肽激素，能引起子宫收缩，促进新生儿的分娩，并在母亲时期刺激乳汁排出。中枢神经系统(CNS)也存在丰富的催产素受体，尤其是边缘系统。催产素参与调节中枢神经系统的社会行为，包括母亲的照料、亲子关系和社会行为。此外，最近的研究表明，催产素在母亲时期具有抗焦虑的作用。然而，确切的分子机制尚不清楚。在蒙布霍资助的实验过程中，我们发现了一个参与催产素调节焦虑的关键分子。催产素诱导雌性小鼠杏仁核片中G蛋白信号调节因子2(RGS2)的表达，RGS2被认为是焦虑的调节器。RGS2在哺乳期小鼠杏仁核中的表达显著高于处女鼠。此外，束缚应激可促进处女小鼠RGS2的表达。这些数据与我们的假设一致，即大脑激素催产素通过增加杏仁核神经元RGS2的表达来控制焦虑和应激反应。我们将进一步研究杏仁核催产素控制焦虑的分子机制。

Oxytocin is a peptide hormone that causes uterine contraction and facilitates the delivery of the newborn, and stimulates the milk ejection during motherhood. Abundant oxytocin receptors also appear in central nervous system (CNS), especially in limbic system. Oxytocin is involved in the regulation of social behaviors, including maternal care, affiliation and social behaviors in CNS.Moreover, recent studies have shown that oxytocin has anti-anxietic effect during motherhood. However, the exact molecular mechanism is unclear.In the course of experiments under the Monbusho grant, we identified a crucial molecule involved in the regulation of anxiety by oxytocin. Oxytocin induced the expression of Regulator of G-protein Signaling2 (RGS2), which is known as a modulator of anxiety, in the amygdala slices of female mice. RGS2 expression in the amygdala of lactating mice was significantly higher than that of virgin mice. Moreover, the expression of RGS2 in virgin mice undergone restraint stress was facilitated compared with that of control mice. These data agree with our hypothesis that the brain hormone oxytocin controls anxiety and stress response by increase of RGS2 expression in amygdala neurons. We will further examine the molecular mechanism of anxiety control by oxytocin in amygdala.