Fundamental aspects of the impact of glucocorticoids on the (immature) brain

In this review, studies on the role of glucocorticoids during brain development are recapitulated with reference to their immediate effects and long-term impact on central functions. Traditionally, this research has focused on detrimental consequences of stress and exogenous glucocorticoid exposure but far less on the ability to develop resilience to stress despite exposure to early adversity. Recent findings suggest that the impact of early life conditions turns out as either harmful or protective depending on later environmental context. To explain this, the concept of 'predictive adaptive response' was introduced, implying that early-life conditions may prepare for life ahead through glucocorticoid programming and phenotypic plasticity with the goal to 'match' future environmental demands. This concept has led to the hypothesis that a 'mismatch' between early and later life conditions can enhance vulnerability to disease. (C) 2008 Elsevier Ltd. All rights reserved.