Acute stress enhances glutamatergic transmission in prefrontal cortex and facilitates working memory

Abstract

The prefrontal cortex (PFC), a key brain region controlling cognition and emotion, is strongly influenced by stress. While chronic stress often produces detrimental effects on these measures, acute stress has been shown to enhance learning and memory, predominantly through the action of corticosteroid stress hormones. We used a combination of electrophysiological, biochemical, and behavioral approaches in an effort to identify the cellular targets of acute stress. We found that behavioral stressors in vivo cause a long-lasting potentiation of NMDAR- and AMPAR-mediated synaptic currents via glucocorticoid receptors (GRs) selectively in PFC pyramidal neurons. This effect is accompanied by increased surface expression of NMDAR and AMPAR subunits in acutely stressed animals. Furthermore, behavioral tests indicate that working memory, a key function relying on recurrent excitation within networks of PFC neurons, is enhanced by acute stress via a GR-dependent mechanism. These results have identified a form of long-term potentiation of synaptic transmission induced by natural stimuli in vivo, providing a potential molecular and cellular mechanism for the beneficial effects of acute stress on cognitive processes subserved by PFC.