Interactions between noradrenaline and corticosteroids in the brain: from electrical activity to cognitive performance

Abstract

One of the core reactions in response to a stressful situation is the activation of the hypothalamus-pituitary-adrenal axis which increases the release of glucocorticoid hormones from the adrenal glands. In concert with other neuro-modulators, such as (nor)adrenaline, these hormones enable and promote cognitive adaptation to stressful events. Recent studies have demonstrated that glucocorticoid hormones and noradrenaline, via their receptors, can both rapidly and persistently regulate the function of excitatory synapses which are critical for storage of information. Here we will review how glucocorticoids and noradrenaline alone and in synergy dynamically tune these synapses in the hippocampus and amygdala, and discuss how these hormones interact to promote behavioral adaptation to stressful situations.

Keywords: amygdala; electrophysiology; glutamate; hippocampus; mouse.

FIGURE 1

Shortly after stress noradrenaline levels in the brain are transiently elevated. Corticosteroids reach the same brain areas later and remain elevated for approximately 2 h. For a restricted period of time neurons are exposed to high levels of both hormones. Noradrenaline primarily works through a rapid G-protein coupled pathway, but long-lasting secondary genomic effects requiring gene transcription may develop. Corticosteroid hormones exert rapid non-genomic actions via membrane receptors, and also slowly, but persistently, regulate neuronal function via nuclear receptors Corticosterone and noradrenaline regulate synaptic transmission and promote memory performance, both alone and in a synergistic fashion. For details, see text. Figure adapted from Joëls et al. (2011).