亚磁场引起小鼠昼夜节律改变和热痛觉敏感增加（英文）

Hypomagnetic Field Alters Circadian Rhythm and Increases Algesia in Adult Male Mice

地外空间的亚磁场环境是影响宇航员健康的一种潜在风险因素.动物和人体实验表明,亚磁场显著影响个体行为和神经系统功能.但是,目前尚缺乏亚磁场对动物行为和生理等多方面影响的系统检测数据.本文构建了一个适用于动物饲养的亚磁场环境（〈500 n T）,并系统检测了30天亚磁场处理对成年雄鼠（C57BL/6,4~6周龄,（20±2）g）的昼夜周期、痛觉、情绪及激素水平的影响.实验结果表明,对比地磁场中饲喂对照组,亚磁场中小鼠的昼夜饮水节律改变、热敏痛觉耐受能力和整体活动水平降低,但是没有发生焦虑或抑郁情绪.亚磁场处理后,小鼠血清去甲肾上腺素水平显著下降.这些结果说明一个月连续亚磁场处理扰乱动物的昼夜活动节律和内分泌,随后可能导致其感知觉能力的变化和运动机能的下降.

It has been established that exposure in the hypomagnetic field（HMF）,which is one of the environmental factor of outer space,has adverse effects on animal and human behavior and brain function.Thus,it is necessary to develop appropriate counteract strategy to avoid the HMF-induced risks to the health of the astronauts during long-term and long-distance manned space mission.However,the physical and mental effects of the HMF in details still await systematic evaluation and the underlying mechanism remains elusive,so far.In this study,we constructed an HMF animal rearing system（ 500 n T） and examined the effects of one-month HMF exposure on the circadian behavior,pain response and emotions in adult male C57BL/6 mice（4~6 weeks old,（20 ± 2） g）.The control animals were reared in the geomagnetic field（GMF）.The HMF-exposed animals exhibited a prolonged alteration of the circadian drinking rhythm and a decrease in general activity,accompanied with an increase in thermal hyperalgesia.But the HMF did not induce obvious depression-like and anxiety-related behaviors.The serum noradrenalin concentration in HMF-exposed mice significantly decreased.These findings indicate that the HMF disturbs the behavior rhythm and the function of endocrine system,which probably leads to the subsequently weakened activities of the animal.