BDNF、TrkB在岛叶慢性电点燃大鼠海马中的表达及与学习记忆的关系

摘要

目的 研究岛叶慢性电点燃癫痫模型大鼠的学习记忆功能,检测脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)、酪氨酸蛋白激酶受体B(Tyrosine receptor kinase B,TrkB)在海马组织中表达,探讨BDNF、TRKB与岛叶点燃大鼠学习记忆的关系.方法 成年SD大鼠随机分为模型组、假手术组、空白对照组,建立大鼠岛叶慢性电点燃模型.用避暗试验方法检测岛叶慢性电点燃模型大鼠学习记忆功能,采用免疫组化和western blot方法分别检测BDNF、TrkB蛋白在海马组织中表达水平,用RT-PCR检测两因子基因表达水平.结果 岛叶慢性电刺激点燃成功后第1天(即0周),学习记忆能力点燃组与空白对照组、假手术组差异无统计学意义(P＞0.05).点燃2周点燃组避暗试验结果的LT为(48.87±3.42s)、EN为(2.75±0.99次);点燃3周点燃组避暗试验结果的LT为(48.71±2.77s)、EN为(2.75±1.15次),与点燃当天(即点燃0周)相比学习记忆功能增强(P＜0.05),点燃4周后与对照组比学习记忆功能明显下降(P＜0.05).BDNF、TrkB表达均在24h达到高峰(P＜0.05),空白对照组、假手术组无明显变化.组间比较、峰值及增幅均出现在2～3周内(P＜0.01),4周后较前几周组明显下降(P＜0.05).结论 岛叶电点燃大鼠学习记忆功能与BD-NF、TrkB在海马中表达总变化趋势一致.BDNF、TrkB与岛叶点燃大鼠学习记忆功能密切相关.%Objective To investigate the expression of active Skeleton Adjustment Protein in rat's Hippocampus in the model of insular chronic electricity - igniting epilepsy and to explore the relation between BDNF,TrkB and learning- remembering ability in the epileptic rat.Methods Adult SD rats were randomly divided into model, sham and control group.The Passive avoidance test was employed to test learning- remembering ability of rats.Immunohistochemistry and western blot was used to determine the expression of BDNF, TrkB in the hippocampus and RT - PCR was exploited to check the gene expression of the two factors.Results There were no significant difference of learning - remembering ability of rats among the igniting group or control group and sham groups ( P ＞ 0.05 ) in the first week after insular chronic ignition when passive avoidance test was examined.The increased learning - remembering ability appeared at the 2nd week ( LT: 48.87 ± 3.42s;EN: 2.75 ±0.99),3rd week(LT:48.71 ±2.77s;EN:2.75 ± 1.15) after the ignition (P＜0.05).It declined at the 4th week.As for the expression of BDNF and TrkB the peak value occurred in the 24 hours (P＜0.05 ) within the experimental groups, it kept increasing at the 2nd and 3rd week and then dropped at the 4th week, but no statistical difference was found between the control and sham groups ( P ＞ 0.05 ).Conclusion The general tendency of the expression of BDNF,TrkB in rat hippocampus after the chronic insular electricity ignition is consistent with the learning - remembering ability of epilepsy rats.BDNF and TrkB are closely associated with the learning- remember ability in epilepsy rats.