Neural correlates of glucocorticoids effects on autobiographical memory retrieval in healthy women.

It is well known that elevated cortisol after stress or after exogenous administration impairs episodic memory retrieval including autobiographical memory (AM) retrieval. This impairment might be mediated by deactivation of a neural network associated with memory retrieval including the prefrontal cortex (PFC) and limbic structures. However, the neural underpinnings of these cortisol effects on AM retrieval have not been investigated yet. In this study, thirty-three healthy women received either placebo or 10 mg hydrocortisone in a double blind cross-over design before completing an AM test during fMRI. In this test, participants are asked to recall specific events from their own past in response to a cue word. In a first step, we analyzed the neural underpinnings of AM retrieval in the placebo condition. We found an activation pattern consistent with core regions involved in autobiographical memory recall, including the ventromedial PFC, anterior medial (am)PFC, inferior frontal gyrus, the posterior cingulate cortex, the tempoparietal junction, the middle temporal gyrus and the hippocampus. Further, we analyzed brain activation during AM retrieval after hydrocortisone compared to placebo. Region of interest (ROI) analyses revealed a hydrocortisone-induced deactivation during AM retrieval in the right amPFC. Results of the ROI analyses were non-significant in the left and right hippocampus, the left and right vmPFC and the left amPFC In sum, during AM retrieval hydrocortisone had the most pronounced effects on the amPFC. This might be explained by the strong involvement of this brain region in self-referential behavior, which is essential for recalling autobiographic information.

The effect of cortisol on autobiographical memory retrieval depends on remoteness and valence of memories.

There is evidence that specificity of autobiographical memory (AM) retrieval is impaired by cortisol. However, it is unknown whether glucocorticoids differentially influence the retrieval of recent versus remote AMs. Therefore, the aim of the current study was to investigate the effects of cortisol on AM retrieval, in terms of memory specificity, with respect to remoteness of the retrieved memories. A placebo controlled, double blind study was conducted. Thirty female and 24 male healthy participants (mean age 24.5, SD=3.7) received either placebo or 10mg hydrocortisone before completing an autobiographical memory test. Participants showed higher memory specificity for recent memories compared to remote ones. There was no main effect of cortisol on AM retrieval. However, interaction effects suggest that cortisol affects remote, but not recent memories, which seems to depend upon valence.