Department of Psychology and Centre for Neuroscience, Brock University, St Catharines ON, Canada.
Prog Neuropsychopharmacol Biol Psychiatry. 2010 Jun 30;34(5):756-65. doi: 10.1016/j.pnpbp.2009.09.019. Epub 2009 Sep 25.
Chronic exposure to stress is known to affect learning and memory in adults through the release of glucocorticoid hormones by the hypothalamic-pituitary-adrenal (HPA) axis. In adults, glucocorticoids alter synaptic structure and function in brain regions that express high levels of glucocorticoid receptors and that mediate goal-directed behaviour and learning and memory. In contrast to relatively transient effects of stress on cognitive function in adulthood, exposure to high levels of glucocorticoids in early life can produce enduring changes through substantial remodeling of the developing nervous system. Adolescence is another time of significant brain development and maturation of the HPA axis, thereby providing another opportunity for glucocorticoids to exert programming effects on neurocircuitry involved in learning and memory. These topics are reviewed, as is the emerging research evidence in rodent models highlighting that adolescence may be a period of increased vulnerability compared to adulthood in which exposure to high levels of glucocorticoids results in enduring changes in adult cognitive function.
慢性应激暴露已知会通过下丘脑-垂体-肾上腺 (HPA) 轴释放糖皮质激素，从而影响成年人的学习和记忆。在成年人中，糖皮质激素改变表达高水平糖皮质激素受体并介导目标导向行为和学习记忆的大脑区域的突触结构和功能。与成年期应激对认知功能的相对短暂影响相比，生命早期暴露于高水平糖皮质激素会通过发育中神经系统的大量重塑产生持久的变化。青春期是大脑发育和 HPA 轴成熟的另一个重要时期，因此为糖皮质激素对参与学习和记忆的神经回路产生编程效应提供了另一个机会。本文回顾了这些主题，以及啮齿动物模型中的新兴研究证据，这些证据表明，与成年期相比，青春期可能是一个易受影响的时期，在这个时期，暴露于高水平的糖皮质激素会导致成年期认知功能的持久变化。
