Stress and glucocorticoids impair retrieval of long-term spatial memory

Abstract

Extensive evidence from animal and human studies indicates that stress and glucocorticoids influence cognitive function. Previous studies have focused exclusively on glucocorticoid effects on acquisition and long-term storage of newly acquired information. Here we report that stress and glucocorticoids also affect memory retrieval. We show that rats have impaired performance in a water-maze spatial task after being given footshock 30 min before retention testing but are not impaired when footshock is given 2 min or 4 h before testing. These time-dependent effects on retention performance correspond to the circulating corticosterone levels at the time of testing, which suggests that the retention impairment is directly related to increased adrenocortical function. In support of this idea, we find that suppression of corticosterone synthesis with metyrapone blocks the stress-induced retention impairment. In addition, systemic corticosterone administered to non-stressed rats 30 min before retention testing induces dose-dependent retention impairment. The impairing effects of stress and glucocorticoids on retention are not due to disruption of spatial navigation per se. Our results indicate that besides the well described effects of stress and glucocorticoids on acquisition and consolidation processes, glucocorticoids also affect memory retrieval mechanisms.

Extinction of a conditioned response in rainbow trout selected for high or low responsiveness to stress

“…The possibility of unavoidable exposure to stress during early development of the HR and LR lines cannot be excluded. Chronically elevated corticosteroid levels have adverse effects on learning and memory (Starkman et al, 2001) and memory retrieval is severely impaired by exposure to short-term elevation of corticosteroid levels when administered prior to testing (de Quervain et al, 1998). In the present study the fish were not subject to any stressors before, during or after conditioning, other than the acute stressor (emersion + confinement) used for conditioning itself.…”

Stress and emotional memory retrieval: Effects of sex and cortisol response

“…By contrast, memory retrieval tends to be impaired following a stressor (Buchanan et al, 2006;de Quervain et al, 1998;. These effects are specific to stressors that result in increased corticosteroid release.…”

“…Stress after learning can improve memory consolidation (see Roozendaal, 2000 for review). By contrast, stress before memory testing can impair memory retrieval performance (Buchanan, Tranel, & Adolphs, 2006;de Quervain, Roozendaal, & McGaugh, 1998;Kuhlmann, Piel, & Wolf, 2005). Roozendaal and colleagues have documented that these differences in the effects of stress on the different phases of memory are dependent on the amygdala.…”

Stress facilitates consolidation of verbal memory for a film but does not affect retrieval.

“…One explanation for our null retrieval findings may be that although the stress induction elevated cortisol enough to facilitate consolidation, levels were not high enough to exert a detrimental effect on retrieval. Support for this comes from a study by de Quervain et al (1998), which showed that the impairing effect of systemic corticosterone administration on retrieval in rats was dose dependent. Pharmacological studies certainly induce a much higher cortisol response than do stress studies, possibly accounting for impaired retrieval findings in these studies.…”