title: Nicotine Significantly Improves Chronic Stress-Induced Impairments of Cognition and Synaptic Plasticity in Mice.
abstract: The aim of this study was to examine if nicotine was able to improve cognition deficits in a mouse model of chronic mild stress. Twenty-four male C57BL/6 mice were divided into three groups: control, stress, and stress with nicotine treatment. The animal model was established by combining chronic unpredictable mild stress (CUMS) and isolated feeding. Mice were exposed to CUMS continued for 28 days, while nicotine (0.2 mg/kg) was also administrated for 28 days. Weight and sucrose consumption were measured during model establishing period. The anxiety and behavioral despair were analyzed using the forced swim test (FST) and open-field test (OFT). Spatial cognition was evaluated using Morris water maze (MWM) test. Following behavioral assessment, both long-term potentiation (LTP) and depotentiation (DEP) were recorded in the hippocampal dentate gyrus (DG) region. Both synaptic and Notch1 proteins were measured by Western. Nicotine increased stressed mouse's sucrose consumption. The MWM test showed that spatial learning and reversal learning in stressed animals were remarkably affected relative to controls, whereas nicotine partially rescued cognitive functions. Additionally, nicotine considerably alleviated the level of anxiety and the degree of behavioral despair in stressed mice. It effectively mitigated the depression-induced impairment of hippocampal synaptic plasticity, in which both the LTP and DEP were significantly inhibited in stressed mice. Moreover, nicotine enhanced the expression of synaptic and Notch1 proteins in stressed animals. The results suggest that nicotine ameliorates the depression-like symptoms and improves the hippocampal synaptic plasticity closely associated with activating transmembrane ion channel receptors and Notch signaling components. Graphical Abstract ᅟ.
authors.affiliation: College of Life Sciences and State Key Laboratory of Medicinal Chemical Biology, Nankai University, 300071, Tianjin, People's Republic of China.
authors.forename: Xueliang
authors.initials: X
authors.lastname: Shang
authors.affiliation: College of Life Sciences and State Key Laboratory of Medicinal Chemical Biology, Nankai University, 300071, Tianjin, People's Republic of China.
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Shang
authors.affiliation: College of Life Sciences and State Key Laboratory of Medicinal Chemical Biology, Nankai University, 300071, Tianjin, People's Republic of China.
authors.forename: Jingxuan
authors.initials: J
authors.lastname: Fu
authors.affiliation: College of Life Sciences and State Key Laboratory of Medicinal Chemical Biology, Nankai University, 300071, Tianjin, People's Republic of China. zhangtao@nankai.edu.cn.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002755:Choice Behavior; D002908:Chronic Disease; D003072:Cognition Disorders / Q000188:drug therapy* / Q000209:etiology* / Q000503:physiopathology; D005786:Gene Expression Regulation / Q000187:drug effects; D005968:Glutamate Decarboxylase / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D017774:Long-Term Potentiation / Q000187:drug effects; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008810:Mice, Inbred C57BL; D009473:Neuronal Plasticity / Q000187:drug effects; D009538:Nicotine / Q000494:pharmacology / Q000627:therapeutic use*; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D013315:Stress, Psychological / Q000150:complications*; D013395:Sucrose; D013550:Swimming
chemical_list: C120997:NR2A NMDA receptor; C121001:NR2B NMDA receptor; D016194:Receptors, N-Methyl-D-Aspartate; D013395:Sucrose; D009538:Nicotine; D005968:Glutamate Decarboxylase; C402565:glutamate decarboxylase 1
keywords: C57 mice; Chronic unpredictable mild stress; Nicotine; Notch1 signaling; Synaptic plasticity