摘要
目的:结合在体和体外实验,探索脑源性神经营养因子(Brain-derived neurotrophic factor,BDNF)在惊厥发作后表达的变化。方法:建立生后20天幼年(IRs)及2～3月健康成年(ARs)Wistar大鼠惊厥持续状态(Status convulsion,SC)模型、原代培养海马神经元惊厥样放电模型,采用免疫组化、ELISA对SC后6个时点大鼠海马、惊厥样放电后海马神经元BDNF的表达变化进行观察分析。结果:(1)SC后大鼠海马各区BDNF阳性着色均有不同程度的增强,以齿状回更为明显;幼年鼠海马BDNF含量在SC后3h即显著增加(从惊厥前的6.65±1.60pg/μg升至11.22±2.44pg/μg)(P<0.05),至惊厥后1天达到高峰,继之逐渐回落,SC后3天仍显著高于发作前水平,7天接近正常;成年鼠海马BDNF在SC后1天显著增加(从惊厥前的5.91±1.63pg/μg升至13.37±5.61pg/μg)(P<0.05),至惊厥后3天达到高峰并高于同时点幼年鼠(P<0.05),之后逐渐下降,持续7天左右。(2)原代培养海马神经元惊厥样放电后24h细胞样本BDNF表达显著高于对照组(P<0.05)。结论:惊厥发作在动物和细胞模型均引起了自身BDNF的高表达,可能是海马神经元对惊厥损伤的内源性保护反应。幼年与成年大鼠海马惊厥后的BDNF表达在反应速度、维持程度上的差异性可能与未成熟脑对自身的保护性反应有关。
Objective：To explore the dynamic process of the expression of brain-derived neurotrophic factor（BDNF）in hippocampus cells after convulsion through in vitro and in vivo experiments. Methods：Seizures with duration of 30 minutes （50min SC） were induced in infant and adult Wistar rats （IRs＆ARs） respectively. The rats were sacrificed at 6 different time points after SC termination.Dynamic change of BDNF level in happocampal cells was investigated by immunocytochemistry and ELISA. Primary hippocampal neurons cultured for 9 days were exposed to magnesium-free extracellular solution media for 3h to establish seizure-like discharge model. BDNF protein expressed in cultured hippocampal neurons was detected by immunocytochemistry. Results：（1）The cells expression of BDNF increased in CA1-CA4 and dentate of hippocampus after SC,and the most positive immunoreactivity was in dentate. The expression of BDNF was remarkably up-regulated at 3h （from 6.65 ±1.60 pg/μg to 11.22±2.44pg/μg） after SC in IRs group （P〈0.05）,and at 1d （from5.91 ± 1.63pg/μg to13.37 ±5.61pg/μg） after SC in ARs group （P〈0.05）. This increases lasted for at least 7d in both IRs and ARs group, with peak levels at ld and 3d respectively. The levels of BDNF in IRs group was still remarkably up-regulated at 3d after SC （P〈0.05）, but remarkably lower than that in ARs group （P〈0.05）.（2）Compared with the control group, the expression of BDNF protein in cultured neurons was remarkably up-regulated in seizure-like discharge model group （P〈0.05） at 24h after discharge. Conclusions：Convulsion could up-regulate expression of BDNF both in animal model of SC and in seizure-like discharge model of cultured hippocampal neurons. This could be the internal protected response of hippocampal neurons to inhibit brain damage induced by Convulsion. There are differences in speed and degree of the expression of BDNF after convulsion between IRs and ARs,whieh indicate that there could be an internal protective response in premature brain after SC.
出处
《重庆医科大学学报》
CAS
CSCD
2007年第3期225-228,274,共5页
Journal of Chongqing Medical University
基金
国家自然科学基金资助(30271382)。
