Abstract: AIM: To study the effects of paroxetine on the psychological stress induced by c-fos gene expression in the rat hypothalamus paraventricular nucleus (PVN) and to explore the molecular mechanism of effects of paroxetine on the stress related anxiety disorders. METHODS: The rat psychological stress model was made by restraint stress.The cortisol was analyzed by radioimmnoassay, and expression of c-fos positive cells was detected by S-P immunohistochemical assay in the rat PVN.RESULTS: The level of cortisol 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 reduced the level of cortisol and inhibited the expression of c-fos positive cells in the PVN after psychological stress. CONCLUSION: The paroxetine can regulate the nerve centre by alleviating the expression of the c-fos in the hypothalamus paraventricular nucleus(PVN) and the activation of HPA pathway.

Key words: paroxitine, psychological stress, c-fos, cortisol hypothalamus, paraventricular nucleus