旱莲草对老年痴呆模型大鼠学习记忆及海马神经递质的影响

Effect of Eclipta on Learning and Memory and Hippocampal Neurotransmitters in the Senile Dementia Model Rats

目的:观察旱莲草对老年痴呆模型大鼠学习记忆能力及海马神经递质的影响。方法:健康成年SD大鼠按随机数字表法分为对照组、模型组、药物低、高剂量组。皮下注射D-半乳糖联合双侧海马注射Aβ_(25-35)构建老年痴呆大鼠模型,各组给予相应药物灌胃治疗8周。用药结束后,观察各组大鼠学习记忆能力、海马神经元形态变化及海马中NE、DA、5-HT的含量和Ch AT、ACh E的酶学活性。结果:与模型组比较,药物高剂量组潜伏期延长,错误次数降低;海马中锥体细胞形态结构基本正常,细胞脱失现象较少;NE、DA和5-HT含量增高,Ch AT活性升高,ACh E活性降低。结论:旱莲草可改善老年痴呆模型大鼠学习记忆功能,其机制可能与改善海马神经元形态结构、减少神经元细胞丢失、改善海马中神经递质的代谢有关。

Objective： To study the effect of Eclipta alba on learning and memory and hippocampal neurotransmitters in Alzheimer＇s disease model rats. Methods： Healthy adult SD rats were randomly divided into 4 groups： control group, model group, low dosage group and high dosage group. The model of Alzheimer＇ s disease was established with subcutaneous injection of D-galactose and microinjection Aβ25-55 on bilateral hippocampus. All rats were treated with different drug lasting 8 weeks. Then, the learning and memory ability of rats were determined. The pathomorphological changes of hippocampal neuron were observed. The contents of norepinephrine（NE） ,dopamine（DA） ,5-hydroxytryptamine （5-HT） and the activities of choline acetyl-transferase （CHAT）, acetylcholin esterase （ACHE） on hippocampus were measured. Results： Compared with the model group, the incubation period prolonged and the error times decreased remarkably in high dosage group ; the pyramidal cells decreased insignificantly with the basic restoration of cell morphology in high dosage group; the content of NE,DA and 5-HT increased significantly; the ChAT activity increased significantly, the AChE activity decreased significantly in high dosage group. Conclusion： Eclipta alba could raise the learning and memory function of AD rats by the mechanism of improving the hippocampus nerve cells＇ morph and structure, improving the metabolism of neurotransmitters on hippocampus.