银杏内酯预处理对拟AD大鼠海马CA1区神经元NFT和ChAT的影响

目的研究银杏内酯（ginkgolides）预处理对拟阿尔茨海默病（Alzheimer’s Disease，AD）模型大鼠中海马CA1区神经原纤维缠结（neurobfillary tangles，NFT）和胆碱乙酰基转移酶（choline acetyl transferase，CHAT）的影响。方法通过在大鼠海马CA1区微量注射冈田酸（Okadaic acid，OA）（0．4mmoL／L，0．5μL／次，隔天1次，共7次）建立拟AD大鼠模型；银杏内酯预处理组于模型制作前2周灌胃（50mg／kg，1次／d），然后通过Morris水迷宫观察大鼠行为学变化，改进的Bielschowsky染色观察海马CA1区NFT的变化，免疫组化法观察海马CA1区ChAT的表达。结果拟AD模型组大鼠出现认知、学习记忆能力减退，海马CA1区出现较多NFT，而ChAT表达减少；银杏内酯预处理组大鼠明显改善上述情况。结论OA的神经毒性可以诱导大鼠学习记忆能力的降低，并且导致胆碱能神经元损伤，功能低下；而银杏内酯预处理组可以显著改善模型大鼠的学习记忆能力，抑制NFT的形成，提高ChAT的活性。

Effects of ChAT expression and NFT formation in Alzheimer''s Disease(AD)-like model rat''s brain by GINKGOLIDES Pretreatment

Objective In order to investigate the effects both NFT and ChAT in Hippocampal CA1. Methods Region of Alzheimer＇ s Disease（AD）-like model rats induced by ginkgolides pretreatment, and microdosis of okadaic acid was injected into hippocamal CA1 region of rat many times,and pretreatment was administered by forced feeding with ginkgolides before two weeks in establishing the AD-like animal model. Then, behavior changes of the rats were observed by morris water maze. Neurobrillary tangles （NFT） of the hippocampus were observed through revised Bielschowsky stain,and the expression of choline acetyl transferase （CHAT） of the hippocampal CA1 region were observed by immunohsitochemistry method. Results After injection of OA,the impairment learning and the memory deficits of the rats were observed in model group,and more NFTs appeared but the expression of ChAT decreased in the hippocampal CA1 region. However, Group with ginkgolides-pretreated obviously improve aboved-mentioned. Conclusion These results suggested that OA＇ s neurotoxicity can cause degrading of the learning and memory capability, and result in cholinergic neuron damage and function deficit. But, ginkgolides pretreatment can significantly improve the learning and memory capabilities of the model rats,inhibit formation of NFT in the hippocampal CA1 region,and increase ChAT activity.