Single-prolonged stress induced mitochondrial - dependent apoptosis in hippocampus in the rat model of post-traumatic stress disorder

Objective The aim of this study was to reveal the possible mechanisms involved in apoptosis induced by single prolonged stress (SPS) in hippocampus of post-traumatic stress disorder (PTSD) rats. Methods SPS is one of the animal models proposed for PTSD. Wistar rats were killed at 1, 4, 7, 14 and 28days after exposure to SPS. Expression of caspase-9, caspase-3, cytochrome c, Bcl-2 and Bax was detected by immunohistochemistry, immunofluorescence, western blotting and electron microscopy. Apoptotic cells were assessed by TUNEL method. Results Our results showed apoptotic cells were significantly increased in hippocampus of SPS rats, accompanied by release of cytochrome c from the mitochondria into the cytosol, increase of caspase-9 and caspase-3 expression and decrease of the Bcl-2 / Bax ratio. Conclusion The results indicate that SPS induced apoptosis in hippocampus of PTSD rats, and the mitochondrial pathway was involved in the process of SPS induced apoptosis. *National Natural Science Foundation of China