It is important to note that glucocorticoids also affect behavioral processes that modulate the impact of stress on the organism. Behavioral analyses indicate that glucocorticoids cause changes in learning strategy, wherein mice switch from spatial learning to stimulus-response learning in the context of acute stress or corticosterone. The switch in learning strategy is blocked by an MR antagonist, suggesting effects mediated by the MR (Schwabe et al., 2010). In addition, mice overexpressing MR fail to extinguish conditioned fear, consistent with impaired behavioral flexibility (Harris et al., 2012). Animals with forebrain deletion of GR or knockdown of GR in the PFC have increased immobility in the forced swim test (Boyle et al., 2005; McKlveen et al., 2013), supporting a role for GR in behavioral strategy selection in this context.
