Neumann Inga D
Institute of Zoology, University of Regensburg, Regensburg, Germany.
Depress Anxiety. 2003;17(3):111-21. doi: 10.1002/da.10070.
In the period before and after parturition, i.e., in pregnancy and lactation, a variety of neuroendocrine alterations occur that are accompanied by marked behavioral changes, including emotional responsiveness to external challenging situations. On the one hand, activation of neuroendocrine systems (oxytocin, prolactin) ensures reproduction-related physiological processes, but in a synergistic manner also ensures accompanying behaviors necessary for the survival of the offspring. On the other hand, there is a dramatic reduction in the responsiveness of neuroendocrine systems to stimuli not relevant for reproduction, such as the hypothalamo-pituitary-adrenal (HPA) axis responses to physical or emotional stimuli in both pregnant and lactating rats. With CRH being the main regulator of the HPA axis, downregulation of the brain CRH system may result in various behavioral, in particular emotional, adaptations of the maternal organisms, including changes in anxiety-related behavior. In support of this, the lactating rat becomes less emotionally responsive to novel situations, demonstrating reduced anxiety, and shows a higher degree of aggressive behavior in the test for agonistic behavior as well as in the maternal defense test. These changes in emotionality are independent of the innate (pre-lactation) level of anxiety and are seen in both rats bred for high as well as low levels of anxiety. Both brain oxytocin and prolactin, highly activated at this time, play a significant role in these behavioral and possibly also neuroendocrine adaptations in the peripartum period.
在分娩前后的时期，即怀孕和哺乳期间，会发生各种神经内分泌变化，并伴有明显的行为改变，包括对外部挑战性情境的情绪反应。一方面，神经内分泌系统（催产素、催乳素）的激活确保了与生殖相关的生理过程，但也以协同方式确保了后代生存所需的伴随行为。另一方面，神经内分泌系统对与生殖无关的刺激的反应性显著降低，例如怀孕和哺乳大鼠下丘脑 - 垂体 - 肾上腺（HPA）轴对身体或情绪刺激的反应。由于促肾上腺皮质激素释放激素（CRH）是HPA轴的主要调节因子，脑CRH系统的下调可能导致母体生物体出现各种行为，特别是情绪上的适应，包括焦虑相关行为的改变。支持这一点的是，哺乳大鼠对新情境的情绪反应性降低，表现出焦虑减少，并且在攻击行为测试以及母体防御测试中表现出更高程度的攻击性行为。这些情绪变化与先天（哺乳前）焦虑水平无关，在高焦虑和低焦虑品系的大鼠中均可见。此时高度激活的脑催产素和催乳素在围产期这些行为以及可能的神经内分泌适应中发挥着重要作用。
