Centre for Neuroendocrinology, Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, 9016, New Zealand.
Sci Rep. 2021 Aug 17;11(1):16700. doi: 10.1038/s41598-021-96341-4.
Stress responses are highly plastic and vary across physiological states. The female estrous cycle is associated with a number of physiological changes including changes in stress responses, however, the mechanisms driving these changes are poorly understood. Corticotropin-releasing hormone (CRH) neurons are the primary neural population controlling the hypothalamic-pituitary-adrenal (HPA) axis and stress-evoked corticosterone secretion. Here we show that CRH neuron intrinsic excitability is regulated over the estrous cycle with a peak in proestrus and a nadir in estrus. Fast inactivating voltage-gated potassium channel (I) currents showed the opposite relationship, with current density being lowest in proestrus compared to other cycle stages. Blocking I currents equalized excitability across cycle stages revealing a role for I in mediating plasticity in stress circuit function over the female estrous cycle.
应激反应具有高度的可塑性，并在不同的生理状态下发生变化。女性发情周期与许多生理变化有关，包括应激反应的变化，但驱动这些变化的机制尚不清楚。促肾上腺皮质激素释放激素（CRH）神经元是控制下丘脑-垂体-肾上腺（HPA）轴和应激诱导的皮质酮分泌的主要神经群体。在这里，我们表明 CRH 神经元的内在兴奋性在发情周期中受到调节，在发情前期达到峰值，在发情期达到低谷。快速失活的电压门控钾通道（I）电流呈现相反的关系，与其他周期阶段相比，电流密度在发情前期最低。阻断 I 电流使兴奋性在周期阶段上均等化，表明 I 在调节雌性发情周期中应激回路功能的可塑性方面发挥作用。
