Neuropediatrics 2006; 37 - PS4_1_1
DOI: 10.1055/s-2006-945786

STUDY OF THE EXPRESSION OF NEUROTROPHIC FACTOR IN HIPPOCAMPUS AND ITS CORRELATIVE FACTORS AFTER STATUS CONVULSION

L Jiang 1, Y Hu 1
  • 1Children's Hospital, Chongqing University of Medical Sciences, Chongqing, P.R. China

Objectives: To investigate the process of the expression of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in hippocampus after Status Convulsion (SC) and explore the influence of age and duration of seizure on the expression of BDNF and NGF.

Methods: Animal model with the different durations of SC (30min,3h) in IRs and ARs were established. The rats were sacrificed at 6 time points (3h to 7d) after 30min of SC termination (30. SC), or 2 time points after 3h of SC termination (3h SC) respectively. The location and cell type expression of BDNF and NGF in the hippocampus were observed by immunohistochemistry. The level of BDNF and NGF at different time points were quantitative analysesed by ELISA.

Results: (1) The cells expression of BDNF and NGF were located mainly in the dentate granule cells and CA1-CA4 pyramidal cells of hippocampus. The most positive immunoreactivity was in cytoplasm, partly in axons. (2) The expression of BDNF had the tendency of increase in IRs and ARs at 3h after SC, with peak levels at 1d and 3d respectively. These increases lasted for at least 7d. Moreover, a several-fold increase was observed at the peak levels. The patterns of NGF expression were similar to that of BDNF after SC. The elevated degree and duration of NGF expression were remarkably lower than that of BDNF, declining abruptly to below control levels by 12h with the characteristic of biphasic increase. (3) The expression of hippocampal BDNF had the positive correlation with the duration of SC, but that of NGF was not. (4) No matter the duration of SC, there was more rapid and evident induction in BDNF of IRs than in ARs. Moreover, the age-related difference was more obvious for the longer duration of SC.

Conclusion: (1) SC induced the expression of BDNF chiefly in hippocampus, and had minor influence on that of NGF. (2) The expression of BDNF was related to age and duration of SC. There was a more rapid and marked induction of BDNF in IRs than that of ARs. The age-related difference had the positive correlation with the duration of SC.