Single-prolonged stress induces increased phosphorylation of extracellular signal-regulated kinase in a rat model of post-traumatic stress disorder.

The extracellular signal-regulated kinase (ERK) signaling transduction pathway has been implicated in multiple physiological processes. It is not clear whether the ERK1/2 pathway participates in post-traumatic stress disorder (PTSD). The aim of this study was to provide novel insights into the mechanisms of how the amygdala participates in PTSD by investigating changes in the ERK1/2 pathway induced by single prolonged stress (SPS). The level of phosphorylated ERK1/2 (pERK1/2) protein was defined in a single-prolonged stress (SPS) animal model of post-traumatic stress disorder. A total of 100 male Wistar rats were randomly divided into a normal control group and SPS groups of 0, 30, 60 and 120 min. pERK1/2 distribution in the amygdala neurons was observed using immune electron microscopy. The expression of pERK1/2 was examined by immunohistochemistry and Western blotting. The pERK protein was located in some cell organelles, such as the mitochondria and neuraxon. Quantitatively, the expression of pERK protein level was significantly increased in the SPS rats. The results suggest that the ERK signal transduction pathway may play a crucial role in the pathology of PTSD.