Single-prolonged stress induces apoptosis in the amygdala in a rat model of post-traumatic stress disorder.

OBJECTIVE: To detect the apoptosis-related Bax and Bcl-2 gene expression and apoptotic cell death in the amygdala region in the single-prolonged stress (SPS) rats.
METHODS: A total of 100 male Wistar rats were randomly divided into a normal control group and SPS groups of 1d, 4d, 7d, and 14d. The expression of Bax and Bcl-2 was detected using immunohistochemistry and Western Blotting; TUNEL-staining and double-labeled flow cytometry (FCM) were employed for the detection and quantification of the apoptotic cells in the amygdala; morphological change of the subcellular structure in amygdala was observed by using the transmission electron microscopy (TEM).
RESULTS: The ratio of Bax/Bcl-2 peaked at SPS 4d and then gradually decreased. The apoptosis peaked at SPS 4d. The TUNEL-positive cells were found in each SPS group and the TUNEL-positive cells rate peaked at SPS 4d. The morphological change of amygdala cells in each SPS group bears typical apoptotic characteristics.
CONCLUSIONS: In the SPS rat brain, we found apoptotic process in the amygdala region which may relate to the pathogenesis of amygdala abnormal function in PTSD.