Preserved LTP and water maze learning in hyperglycaemic-hyperinsulinemic ZDF rats
Preserved LTP and water maze learning in hyperglycaemic-hyperinsulinemic ZDF rats
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DOI：
10.1016/j.physbeh.2004.08.031
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发表时间：
2004-12-15
影响因子：
2.9
通讯作者：
Gagnon, S
中科院分区：
文献类型：
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作者：
Bélanger, A;Lavoie, N;Gagnon, S
先前的研究已经证明，在表现为1型糖尿病（TID）的动物中产生认知缺陷以及海马功能障碍。本研究检查了在Zucker糖尿病脂肪（ZDF）大鼠出现2型糖尿病（T2D）症状后，是否也可以重现这种缺陷。在实验1（实验1）动物出现1型糖尿病症状后5周和实验2（实验2）动物出现1型糖尿病症状后8周，使用Morris水迷宫进行学习和记忆评估。在水迷宫中的测试显示，ZDF大鼠正常学习任务，尽管在未经治疗的糖尿病5或8周后，对照组大鼠游泳速度明显加快。从电生理学的角度来看，我们观察到，突触功能的完整性也保存在ZDF大鼠的海马脑片的CA1区的长时程增强（LTP）没有观察到改变。结论：在2型糖尿病（T2D）动物模型中，高血糖不是影响水迷宫学习和UP的唯一因素。实验结果提示，ZDF大鼠对认知和电生理功能障碍的抵抗可能与高胰岛素血症的保护作用有关。事实上，与对照大鼠相比，ZDF大鼠在测试结束时的血浆胰岛素水平测量值显著上级。(C)2004年爱思唯尔公司All rights reserved.
Previous investigations have demonstrated that cognitive deficits as well as hippocampal dysfunctions are generated in animals presenting manifestations of Type 1 diabetes (TID) mellitus. The present study examined whether such deficits can also be reproduced in the Zucker Diabetic Fatty (ZDF) rats after they developed symptoms of Type 2 diabetes (T2D). Learning and memory assessments were performed using the Morris water maze 5 weeks after the animals presented symptoms of Type 1 diabetes for Experiment 1 (Exp 1) and after 8 weeks for Experiment 2 (Exp 2). Testing in the water maze revealed that ZDF rats learned the task normally, although control rats were found to swim significantly faster after 5 or 8 weeks of untreated diabetes. From an electrophysiological perspective, we observed that the integrity of synaptic function was also preserved in ZDF rats as no alterations in long-term potentiation (LTP) were observed in the area CA1 of hippocampal slices. It is concluded that hyperglycaemia is not the only factor influencing water maze learning and UP in this animal model of Type 2 diabetes (T2D). The experiments suggest that the resistance of ZDF rats to cognitive and electrophysiological dysfunctions might be related to the protective action of hyperinsulinemia. Indeed, measurements of the plasma insulin level at the end of testing were significantly superior in ZDF rats in comparison to control rats. (C) 2004 Elsevier Inc. All rights reserved.