Chronic Unexpected Mild Stress Destroys Synaptic Plasticity of Neurons through a Glutamate Transporter, GLT-1, of Astrocytes in the Ischemic Stroke Rat

作者：Dafan Yu, Zhenxing Cheng, Idriss Ali Abdoulaye, Jiamin Wang, Kai Le, Enkhmurun Chibaatar, Yijing Guo · 发表于：Neural Plasticity · 年份：2019 · DOI：10.1155/2019/1615925 · 被引用次数：31 · 研究领域：Neuroscience and Neuropharmacology Research、Neurological Disease Mechanisms and Treatments、Amino Acid Enzymes and Metabolism

Background and Objective . Chronic unexpected mild stress (CUMS) destroys synaptic plasticity of hippocampal regenerated neurons that may be involved in the occurrence of poststroke depression. Astrocytes uptake glutamate at the synapse and provide metabolic support for neighboring neurons. Currently, we aim to investigate whether CUMS inhibits synaptic formation of regenerated neurons through a glutamate transporter, GLT-1, of astrocytes in the ischemic stroke rats. Method . We exposed the ischemic stroke rats to ceftriaxone, during the CUMS intervention period to determine the effects of GLT-1 on glutamate circulation by immunofluorescence and mass spectrometry and its influences to synaptic plasticity by western blot and transmission electron microscopy. Result . CUMS evidently reduced the level of astroglial GLT-1 in the hippocampus of the ischemic rats ( p < 0.05 ), resulting in smaller amount of glutamate being transported into astrocytes surrounding synapses ( p < 0.05 ), and then expression of synaptophysin was suppressed ( p < 0.05 ) in hippocampal dentate gyrus. The ultrastructures of synapses in dentate gyrus were adversely influenced including decreased proportion of smile synapses, shortened thickness of postsynaptic density, reduced number of vesicles, and widened average distance of the synaptic cleft (all p < 0.05 ). Moreover, ceftriaxone can promote glutamate circulation and synaptic plasticity (all p < 0.05 ) by raising a...