Single prolonged stress induces changes in the expression of mineralocorticoid receptor in the medial prefrontal cortex in a rat model of post-traumatic stress disorder.

It is not clear whether or not the mineralocorticoid receptor (MR) is involved in post-traumatic stress disorder (PTSD). The purpose of this study was to provide novel insights into the mechanism(s) through which the medial prefrontal cortex (mPFC) plays a role in PTSD by investigating MR expression in the mPFC of rats exposed to single prolonged stress (SPS), which is an established animal model for PTSD. A total of 90 healthy, male Wistar rats were selected for this study and randomly divided into normal control and SPS groups of 1, 7, 14 and 28 days. This study investigated the changes in MR expression in the mPFC of rats after SPS, which revealed pathogenetic mechanisms. The expression of MR in the mPFC was examined by immunofluorescence, western blotting and reverse transcription-polymerase chain reaction (RT-PCR). SPS exposure resulted in a significant change in MR expression in the SPS model groups compared with the normal control group. The MR protein was found to be localized in the cytoplasm and its expression levels were significantly increased in SPS rats, peaking at SPS 7 days, followed by a gradual decrease; however, a positive expression revealed a restoratory increase in the SPS-28 day group. The results suggest that MR plays an important role in the pathology of PTSD.