As during ER stress, activation of ATF6 is known to specifically up regulate chaperones, PDIs, as well as Caspase 12, and consequently lead to apoptosis [29], thus, the aim of this study was to investigate whether endoplasmic reticulum -related pathway is involved in SPS induces apoptosis in the mPFC of PTSD rats by examining the expression levels of ATF6 alpha (ATF6α), two important downstream molecular chaperone: GRP78 and ERP57, and apoptotic factors Caspase 12, Caspase 9, and Caspase 3. This evidence concerns the gene CASP9 and post-traumatic stress disorder.