杏仁核电点燃大鼠认知功能及海马α7型神经烟碱胆碱能受体的表达

摘要

Objective:To investigate cognitive function and emotional deficits in the amygdala kindling model of epilepsy and the expression of the α7 nicotinic acetylcholine receptors(α7 nAChR)in hippocampus. Methods:The 40 male SD rats were randomly divided into 1-and 2-week control groups (C1 and C2 groups, n=8) and 1-and 2-week kindling groups (K1 and K2 groups, n=12). The kindling group that had been evoked for 5 consecutive stage V seizures were established by the electrical stimulation fully-kindled amygdala seizures. Then emotional deficits were tested by open field test, learning and memory abilities were tested by Morris water maze, and the expression level of α7 nAChR in hippocampus was determined by immu-nohistochemical techniques and Western blotting. Results:In the open-field exploratory maze, compared with the control group, the numbers of grids(Flu, = 24. 77, Pla, = 0. 00, F2lu = 42. 86, P2u,=0. 00) and standing time(F1w, = 56. 18, P1w= 0. 00, F2w, = 42. 25, P2w = 0.00) of K1 and K2 groups were all obviously decreased,while the numbers of feces(F1w, = 10.08, P1w = 0.01, F2w = 31.22, P2w = 0.00) of K1 and K2 groups were increased, and compared with C1 and C2 groups, the difference between the escape latency(F1w=3.139, P1w, = 0.095; F2w = 0.884, P2w = 0.361) and the time in the platform quad-rant(F1w = l.907, P1w = 0.185, F2w = 0.446, P2w=0.513) of K1 and K2 groups were not significant, and the expressions of α7 nAChR of K1 and K2 groups were all increased (E1w = 15. 70, P1w = 0.02, F2w= 24.61, P2w = 0.01). Contusion:Kindling might differentially result in emotional deficits, and at the same time the expression level of α7 nAChR was significant increased in the hippocampus of the rat amygdale electrical kindling epilepsy model. But its learning and memory abilities did not change, which may be correlated to the age of onset, duration and type of seizures, seizure frequency and medication.%目的:本研究旨在探讨杏仁核电点燃大鼠恐惧状况、学习记忆能力及海马区a7型神经烟碱胆碱能受体(α7 nAChR)表达变化.方法:随机将雄性SD大鼠分为手术对照1周组、2周组及电点燃1周组、2周组.实验结束后,用旷场实验检测大鼠的活动水平、探索能力及恐惧状况；Morris水迷宫实验检测大鼠学习记忆能力；免疫组织化学和免疫印迹检测大鼠海马区a7 nAChR表达变化.结果:电点燃组大鼠点燃成功率为91.7％.旷场实验检测结果显示,与手术对照组比较,点燃1周组和2周组大鼠活动的格子数(F1w=24.77,P1w=0.00；F2w=42.86,P2w=0.00)、站立次数(F1w =56.18,P1w=0.00；F2w=42.25,P2w=0.00)及排出粪便的颗粒数(F1w=10.08,P1w=0.01,F2w=31.22；P2w=0.00)有差异,具有统计学意义；Morris水迷宫检测结果显示,与手术对照组比较,点燃1周和2周组大鼠搜寻平台的潜伏期(F1w=3,139,P1w=0.095；F2w=0.884,P2w=0.361)及在平台所在象限的搜寻时间百分比(F1w=1.907,P1w=0.185；F2w=0.446,P2w=0.513),差异均无统计学意义；免疫组织化学及免疫印迹结果显示,与手术对照组比较,点燃1周组和2周组大鼠脑海马区α7 nAChR表达均增高(F1w=15.70,P1w=0.02,F2w=24.61,P2w=0.01).结论:大鼠杏仁核电点燃1周和2周后,导致了其情感行为异常,增加了脑海马区α7 nAChR的表达,但对其学习和记忆能力的影响不明显,可能与点燃部位、发作频率、发作强度及发作的持续时间有关.