Involvement of FKBP5, but not of stress, in alcohol memory reconsolidation

Relapse is a fundamental challenge in drug addiction, often evoked by exposure to drug-associated cues. Upon retrieval, memories become temporarily labile before re-stabilizing in a process termed reconsolidation. Therefore, targeting the reconsolidation process offers a therapeutic approach for relapse prevention via the disruption of the drug-cue memories. We recently demonstrated that retrieval of contextual alcohol memories increased the expression of the mRNA encoding for FK506 binding protein 51 (FKBP51), a regulator of the hypothalamic-pituitary-adrenal (HPA) axis. Here, we explored the role of the HPA axis, and FKBP5/FKBP51 in particular, in the reconsolidation of alcohol memories. We found that the FKBP51 inhibitor SAFit2 given before alcohol-memory retrieval using contextual cues prevented the extinction of alcohol place preference behavior in female mice, suggesting that this protein may play a role in cognitive flexibility in a sex-dependent manner. Conversely, the retrieval of alcohol memories using an odor-taste cue did not affect Fkbp5 expression in rats with a history of chronic alcohol consumption, suggesting that FKBP5 may play a differential role in different alcohol-associated memories. In addition, we provide evidence for HPA axis activation following alcohol memory retrieval, by showing that exposure to an alcohol-associated context led to elevated corticosterone secretion. However, we found that the reconsolidation process was unaffected by HPA axis-related manipulations, namely stress exposure, and administration of corticosterone or the glucocorticoid receptors inhibitor, mifepristone. Our results suggest that although FKBP5 can affect cognitive flexibility, and thereby impact the reconsolidation of alcohol memories, this effect is not likely mediated by HPA axis-related mechanisms.