Objective To observe the expression of
brain-derived neurotrophic factor (BDNF) in four brain areas of rats with the bilateral
fimbria-fornix
transection and ovariectomy, and with the estrogen replacement therapy.Methods The experiment was a 2×2 factorial design. Thirty Wister female rats were randomly divided into 4 model groups: fimbria-fornix transection (FF) group, ovariectomy (OVX) group, fimbria-fornix transection combined with ovariectomy (OF) group, and control group. The brain bilateral fimbria-fornix was transected in the stereotaxic apparatus. Secondly, estrogen replacement therapy model (OF+E 2 group) was made by treating the OF rats with the estradiol (1 mg/kg) once a week for 28 days. Immunoreactive cells of BDNF in the hippocampus CA1, cerebral cortex, amygdaloid complex and Meynert nucleus were measured with immunohistochemical way.Results Bilateral fimbria-fornix transection and ovariectomy had an interaction on the expression of BDNF in the four areas (P<0.001). The expression of BDNF remarkably decreased in hippocampus CA1, cerebral cortex, amygdaloid complex and Meynert nucleus in rats with the bilateral fimbria-fornix transaction (F=281.834-649.959, P<0.001) or ovariectomy (F=260.035-943.254, P<0.001), and the most marked decrease in Meynert nucleus area was in rat with ovariectomy combined with fimbria-fornix transection (F=17.505, P<0.01). The expression of BDNF was significantly higher in the OF+E 2 group than that in the OF control group (t=5.961-20.091, P<0.01).Conclusions The results indicate that the bilateral fimbria-fornix transection and ovariectomy decrease the expression of BDNF. The estrogen replacement therapy may be a useful way of improving the expression of BDNF.