Stress-Induced Increases in Levels of Caspases in the Prefrontal Cortex in a Rat Model of PTSD

摘要

We investigated the levels of expression of caspase-3 and 9 in the medial prefrontal cortex (mPFC) of rats subjected to single prolonged stress (SPS) to provide a novel insight into the mechanism of how this cortical region is related to post-traumatic stress disorder (PTSD). Fifty male Wistar rats were divided into the control group and four SPS groups examined at days 1, 4, 7, and 14 after treatment. Expression of caspase-3 in SPS groups was significantly greater when compared with the control group (P < 0.05) and peaked at day 7 after exposure to SPS. In the control group, the intensity of fluorescence of caspase-9-positive cells was low, while that in the SPS groups was significantly higher (P < 0.01) and peaked at day 4 after exposure to SPS. After SPS episodes, levels of mRNA of caspase-3 and caspase-9, compared with those in the control group, gradually increased and peaked at days 7 and 4, respectively (P < 0.01). Therefore, changes of expression of caspase-9 and caspase-3 may play an important role in the pathogenesis of PTSD.