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糖尿病对大鼠海马神经协同性的影响

刘凯, 谢康宁, 乔志梅, 高上凯, 洪波

清华大学医学院生物医学工程系，北京 100084； 中国科学院自动化研究所高技术创新中心，北京 100190； 第四军医大学生物医学工程学院，西安 710032

摘要

离体电生理和行为研究表明，糖尿病会对海马功能造成负面影响。本研究采用活体胞外电极记录方式，在麻醉条件下，记录STZ 诱发糖尿病大鼠以及正常大鼠海马区神经元自发放电。运用相干系数和相位同步的分析技术，对在海马区同一位点记录到的神经元放电和局部场电位(local field potentials)的低频振荡(1~4 Hz)进行时域协同性的分析。结果显示，糖尿病大鼠的相干系数值(0.617±0.028)与正常大鼠(0.730±0.024)相比普遍偏低(P=0.005)。而相位同步的分析方法更直观地反映了神经元放电与低频局部场电位的时域协同性程度，通过von Mise 拟合的一个相位聚集参数κ 来衡量相位同步程度的大小，发现糖尿病大鼠的相位同步系数κ 值(0.347±0.113)远低于正常大鼠(1.174±0.134) (P<0.001)。在此研究中，相干系数和相位同步两种分析结果都表明糖尿病会对大鼠海马神经元放电与低频局部场电位的协同性造成负面影响。这种负面影响或许是糖尿病造成记忆功能障碍的神经网络机理。

关键词： 相干系数; 相位同步; 局部场电位; 低频振荡; 糖尿病; 海马

分类号：Q426

Impaired neural coordination in hippocampus of diabetic rat

Liu Kai, XIE Kang-Ning, QIAO Zhi-Mei, GAO Shang-Kai, HONG Bo

Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China； Department of Hightech Innovation Centre, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China； Faculty of Biomedical Engineering, the Fourth Military Medical University, Xi’an 710032, China

Abstract

In vitro electrical neurophysiological and behavioural studies have shown that diabetes mellitus negatively affects hippocampal
function. In this study, by using in vivo extracellular recording, the spontaneous neural activity was obtained from hippocampus
of anaesthetized rats in both streptozotocin-induced diabetes group and normal control group. Temporal relationship between neuronal
firing and slow oscillation (1-4 Hz) of local field potentials (LFPs) in hippocampus was analyzed using coherence and phase locking
measurement. Lower coherence value (0.617±0.028) was observed in diabetic rats than that in control rats (0.730±0.024) (P=0.005).
Furthermore, phase-locking measurement using von Mises fitting parameterized by a concentration parameter κ showed a lower degree
(κ = 0.347±0.113) of temporal coordination between neuronal spiking and slow oscillation of LFPs in the hippocampus of diabetic rats
than that of normal ones (κ = 1.174±0.134) (P<0.001). Both approaches demonstrated that diabetes can indeed impair the temporal
coordination between neuronal spiking and slow oscillation of population activity in hippocampus. This observed neural coordination
impairment may serve as a network level mechanism for diabetes-induced memory deterioration.

Key words: coherence; phase locking; local field potential; slow oscillation; diabetes mellitus; hippocampus

收稿日期：2009-04-16　　录用日期：2009-07-22

通讯作者：洪波　　E-mail: hongbo@tsinghua.edu.cn

引用本文：

刘凯, 谢康宁, 乔志梅, 高上凯, 洪波. 糖尿病对大鼠海马神经协同性的影响[J]. 生理学报 2009; 61 (5): 417-423.

Liu Kai, XIE Kang-Ning, QIAO Zhi-Mei, GAO Shang-Kai, HONG Bo. Impaired neural coordination in hippocampus of diabetic rat. Acta Physiol Sin 2009; 61 (5): 417-423 (in Chinese with English abstract).