SGK、糖皮质激素及其受体在应激促进空间学习记忆中的作用

应激会对动物的学习记忆能力产生影响,这种影响呈一种倒U型关系,即当应激强度过大或时间过长时这种影响往往是一种损伤,而适度的应激会对学习记忆产生促进作用。目前认为应激激活了下丘脑-垂体-肾上腺（hypothalamo-pituitary-adrenal,HPA）轴,诱导糖皮质激素的释放。适量的糖皮质激素会促进长时程增强（long-term potentiation,LTP）的形成,从而促进学习记忆。血清/糖皮质激素诱导激酶（serum and glucocorticoid regulated protein kinase,SGK）作为糖皮质激素诱导的一个激酶,参与了多种离子通道的调节,能够促进神经元的存活和轴突的再生。研究发现SGK的表达也会促进空间学习记忆能力。

The Roles of SGK and GR in The Spatial Learning and Memory Enhancement

Stress can affect the animals' learning and memory behavior.Heavy stress will impair learning and memory,while moderate stress has an improvement effect.Glucocorticoids,such as corticosterone,are released by the adrenal cortex in response to a wide range of stressors and related with learning and memory.These notably bind to mineralcorticoid and glucocorticoid receptors(MRs and GRs)in the hippocampus,which is involved in the processing of spatial and contextual information.The effects of stress and glucocorticoids on hippocampus-dependent learning follow an inverted U-shaped dose-response relationship;extreme low and high levels may impair consolidation,whereas moderate activation seems to be a prerequisite for the long-term storage of information.SGK(serum and glucocorticoid regulated protein kinase) which is a kind of kinase stimulated by glucocorticoid can regulate many ionic channels and helpful to neurons survival and axon regeneration.Some researches narrated that SGK high expression can improve special learning and memory.