Changes in 5-HT1A receptor in the dorsal raphe nucleus in a rat model of post-traumatic stress disorder.

Post-traumatic stress disorder (PTSD) is characterized mainly by symptoms of re-experiencing, avoidance and hyperarousal as a consequence of catastrophic and traumatic events that are distinguished from ordinary stressful life events. Single-prolonged stress (SPS) is an established animal model for post-traumatic stress disorder (PTSD). The dorsal raphe nucleus (DR)-serotonin (5-HT) system is markedly affected by swim stress and has been implicated in affective disorders. The 5-HT1A receptor (5-HT1AR) is critically involved in regulating mood and anxiety levels. In this study, we investigated changes in the expression of 5-HT1AR in the DR of rats after SPS that may reveal part of the pathogenesis of PTSD. 5-HT1AR expression in the DR was examined using immunohistochemistry, Western blotting and reverse transcription polymerase chain reaction. The expression of 5-HT1AR in the DR after SPS exposure was increased when compared to that in the control group (P<0.05). These findings indicate an increase in 5-HT1AR in the DR of SPS rats, which may play important roles in the pathogenesis of PTSD rats.