【摘要】 噪音日益严重地影响着人类的健康,为了探讨慢性噪音对小鼠情绪和注意力的影响及其分子机制.分别给予6周龄雄性小鼠以噪音刺激(75 dB,8 h/d),连续30 d后检测小鼠与情绪和注意力相关的行为表现.结果发现,噪音组小鼠在开场实验中心区域运动距离的百分比升高,在明暗箱实验中表现为在明箱中运动时间增多以及在强迫游泳实验中静止不动的时间显著减少,均与对照组有显著差异.在痕迹恐惧实验中,两组小鼠在线索式恐惧测试中的僵直程度相似,说明持续的声音暴露没有影响小鼠的注意力.运用荧光定量PCR技术检测海马和下丘脑相关基因的表达,发现噪音组小鼠GAD65 mRNA水平、GABAAα1/GABAAα3比例和NR2A/NR2B的比例均下降,且NR1 mRNA表达量上调.以上结果显示,慢性持久的噪音暴露使小鼠产生低焦虑样行为,其分子机制可能涉及谷氨酸能兴奋性神经元活动增强,以及γ-氨基丁酸能神经元对大脑活动抑制功能的减弱.更多还原

【Abstract】 Noise is recognized as a serious health problem.To understand the effects of chronic noise exposure on emotion and attention in mice and its underlying molecular mechanisms,the C57BL/6 male mice(postnatal 6 weeks) were exposed to noise(75dB,8 h daily) and environment noise(control) separately for consecutive 30 days,then their behaviors related to emotion and attention were analyzed.The results showed that the noise group explored the center portion of the field(as center locomotor) more than control group did in open field test,and it explored the light compartment more in light-dark box test and exhibited less immobility time in forced swim test compared to the control group,with significant difference.However,the cued test in trace fear conditioning revealed no obvious difference on freezing time at each of three consecutive tone tests between the two groups,which means there is no attention influence after noise exposure.Correlative molecules in hippocampus and hypothalamus regions were detected by real time quantitative PCR.The expression level of GAD65 mRNA and GABAAα1/GABAAα3 ratio and NR2A/NR2B ratio decreased,while the expression level of NR1 mRNA increased in the noise group.All these results showed that the mice exhibited excited or low-anxiety behavior after being exposed to chronic noise,and that the glutamatergic neurons activity was enhanced while the GABAergic neurons activity was reduced could be the molecular mechanisms involved in behavior alterations.更多还原