OBJECTIVETo study the changes of brain-derived neurotrophic factor (BDNF) following repeated febrile seizures in rats and its possible correlation with neurocyte apoptosis.

METHODSFifty-one male Sprague-Dawley (SD) rats were randomly assigned to three groups: normal control (n=14), febrile seizure (FS, n=18), hyperthermia alone (n=19). Febrile seizures were induced by hot water bath. The level of BDNF in the hippocampal homogenate was measured using ELISA and the expression of BDNF in various brain regions was measured by immunohistochemistry. The neurocyte apoptosis of the brain was determined by TdT-mediated biotinylated-dUTP nick end labling (TUNEL).

RESULTSThe level of BDNF in the hippocampus in the FS group(89.9+/-12.5 ng/g)was higher than that in the normal control group(54.4+/-18.9 ng/g)and in the hyperthermia alone group (64.1+/-15.0 ng/g) (P<0.01). The OD value of BDNF positive neurons in various brain regions of the FS group was significantly higher than that of the normal control group (P<0.01) and the hyperthermia alone group (P<0.01). The FS group had significantly higher apoptotic index in various brain regions than the normal control and the hyperthermia alone groups (P<0.01). There was a positive correlation between the expression of BDNF and the apoptotic index in various brain regions (r=0.332, P<0.05).

CONCLUSIONSBDNF expression in the brain increases following repeated febrile seizures in rats, and the increased BDNF expression is correlated with neurocyte apoptosis.