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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

Received: 2009-04-16　　Accepted: 2009-07-22

Corresponding author: 洪波　　E-mail: hongbo@tsinghua.edu.cn

Citing This Article：

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).