Abstract: AIM: To investigate the molecular mechanisms of antianxiety drugs on the rats with restraint stress.METHODS: The rat stress model was made by restraint stress. The behaviors of rats were tested in openfield conditions, and the expression of c-fos positive cells was detected by S-P immunohistochemical assay in hypothalamus.RESULTS: The crossing scores, the rearing scores and the expression of c-fos positive cells increased more significantly in the other groups than that in the control group, but decreased in the paroxetine group. The paroxetine inhibited the behaviors and the expression of cfos positive cells in the hypothalamic paraventricular nucleus (PVN)of rats after immobilization stress.CONCLUSION: The effects of paroxetine on the anxiety disorders in rats may be related to the downregulation of the expression of the c-fos in the hypothalamic paraventricular nucleus (PVN).

Key words: paroxetine, stress, behavior, c-fos, hypothalamic, paraventricular nucleus