β-淀粉样多肽25～35片段诱导的大鼠学习记忆功能障碍

摘要

AIM　To determine whether microinjection of β-amyloid peptide fragment 25～35 (Aβ25～35) into rat hippocampus induces the learning and memory dysfunction.METHODS　Microinjection of Aβ25～35 into hippocampus induced the rat learning and memory dysfunction. Step-down test, Shuttle-box test, and Morris water maze test were used to evaluate rat learning and memory function;The sections were stained with haematoxylin-eosin (HE),the amyloid deposits were detected using Congo Red and silver.RESULTS　The latency of Aβ25～35-treated rats shortened,the stimulating time prolonged,and the numbers of errors increased in the step-down test;Shuttle-box test showed that Aβ25～35 caused the latency and numbers of active escape reduction and the numbers of passive avoidance increase; Also in morris water maze, Aβ25-35 induced an impairment in rat spatial resolution; In Aβ25～35-treated group, a significant decrease in the numbers of neurons in cortex and hippocampus,a massive glial reaction and neurophilic phenomenon were detected by HE staining; the positive vascular amyloidosis by Congo red and fibrils by Ag staining were also observed.CONCLUSION　Microinjection of Aβ25～35 into rat hippocampus may induce the learning and memory dysfunction and pathological changes which were similar to that found in Alzheimers disease (AD) brain.%目的诱导能模拟人类Alzheimer病（AD）的大鼠病理模型，用于该病的病理机制和治疗药物的研究。方法采用双侧海马内一次性注射β-淀粉样多肽25～35片段（Aβ25～35）诱导大鼠AD模型；行为测试采用跳台法、穿梭法和Morris水迷宫法；病理检测采用HE染色、刚果红染色和银染。结果跳台法、穿梭法和Morris水迷宫法试验结果提示海马内注射Aβ25～35可引起大鼠主动和被动回避性反射及空间分辨力降低；病理检查发现皮质和海马神经元数量减少、退变，皮质下血管淀粉样变及脑内出现纤维蛋白丝状物。结论海马内注射Aβ25～35诱导的大鼠学习记忆功能低下模型在功能和形态上类似于AD。