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[Chronic effects of oligomeric Aβ(1-42) on hippocampal synaptic plasticity in vivo.] [Article in Chinese]

TAN Tao, ZHANG Bao-Liang, TIAN Xin^*

1 Institute of Biomedical Engineering； 2Laboratory of Neural Engineering, Research Center of Basic Medical Science, Tianjin Medical University, Tianjin 300070, China； 3Tianjin Neurological Institute, Tianjin 300070, China

Abstract

Synaptic plasticity, including long-term potentiation (LTP) and long-term depression (LTD), is widely considered as one of the major mechanisms underlying learning and memory. This study explored hippocampal synaptic plasticity and spatial memory formation of an Alzheimer’s disease (AD) rat model established by intrahippocampal injection of oligomeric Aβ1–42. Twenty four Sprague-Dawley rats at 2.5 months of age were randomly divided into AD and control groups, and were bilaterally injected with 5 μg oligomeric Aβ1–42 or normal saline into dentate gyrus (DG) of hippocampus. Morris water maze test was used to observe the capability of learning and memory of two groups, 30 d after injection. To investigate the variations of paired-pulse facilitation (PPF) and range of synaptic plasticity, field potentials were recorded in the DG of the dorsal hippocampus by stimulating the perforant path (PP). The results showed that oligomeric Aβ1–42 obviously impaired spatial memory formation in rats (P < 0.05). Furthermore, oligomeric Aβ1–42 reduced the PPF ratio (P < 0.05) and hippocampal LTP formation (P < 0.05), while facilitated the hippocampal LTD formation (P < 0.05). These data suggest that chronic Aβ aggregation impairs synaptic plasticity of hippocampal PP-DG pathway, which may be involved in the spatial memory deficit in AD rats.

Key words: Aβ1–42; Alzheimer's disease; hippocampal perforant pathway; long-term potentiation; long-term depression; rats

Received: 2010-08-31　　Accepted: 2011-04-07

Corresponding author: 田心　　E-mail: tianx@tijmu.edu.cn

Citing This Article：

TAN Tao, ZHANG Bao-Liang, TIAN Xin. [Chronic effects of oligomeric Aβ(1-42) on hippocampal synaptic plasticity in vivo.] [Article in Chinese]. Acta Physiol Sin 2011; 63 (3): 225-232 (in Chinese with English abstract).