摘要
目的研究急性热应激条件下小鼠脑组织超微结构及脑电图的变化。方法采用恒温恒湿动物箱建立不同温度(24℃、34℃、37℃、38.5℃、40℃、42℃,各60min,相对湿度60%)的热应激模型。观察成年昆明种小鼠的行为表现,监测体温及脑电图。透射电镜观察大脑海马组织的细胞形态改变。结果34℃环境温度仅引起小鼠直肠温度升高。37℃以上的环境温度不仅使小鼠直肠温度升高,还使其发生脱水,且诱发小鼠惊跳、逃窜行为;脑电图出现明显异常,幅值增大,节律减慢,但42℃环境温度下脑电图频率增快。电镜检查结果提示只有42℃环境温度才引起海马组织病理性改变。结论小鼠对环境高热敏感,随着核心温度升高出现行为性体温调节,其脑电图及脑组织细胞形态学变化反映了高温环境对中枢神经系统的影响。40℃以下环境高温引起的急性脑功能紊乱是可逆的,42℃的环境温度可造成脑组织结构改变,大多数小鼠会因中暑而死亡。
Objective To study the changes in the central nervous system in adult mice after various degrees of acute heat stress. Methods Adult mice placed in insulated cages were exposed to 24℃, 34℃, 37℃, 38. 5℃, 40℃ or 42℃ for 60min respectively with a constant humidity of 60%. The behavior response was carefully monitored. Rectal temperature was measured before the exposure and after the exposure. Electroencephagrams were taken. Then the hippocampal neurons of these animals were examined with transmission electron microscope. Results Heat stress at 34℃ for 60 min only raised the rectal temperature, and heat stress above 37℃ for 60 min not only raised rectal temperature, but also induced water loss and irritability and attempt to escape. Abnormal EEG with increased amplitude and retarded rhythm could be observed. However, when mice were exposed to 24℃ and 34℃ such behavior did not appear. After exposure to 42℃, EEG frequency increased and pathological changes in hippocampus neurons were found. The main ultrastructural changes included degeneration of hippocampal neurons, expansion of space around capillary, decrease in number of synaptic vesicle, and decomposition of synapse. Conclusion Mice were very sensitive to heat stress. An increase in core temperature could induce behavioral thermoregulation. EEG and electron microscopic study revealed changes in the central nervous system after heat stress. Following exposure to high environmental temperature under 40℃, acute dysfunction of brain was reversible. At 42℃, damage to the brain tissue occurred, and most mice died of heat stroke.
出处
《解放军医学杂志》
CAS
CSCD
北大核心
2006年第2期165-166,共2页
Medical Journal of Chinese People's Liberation Army
关键词
热应激障碍
行为
脑电描记术
海马
显微镜检查
电子
扫描透射
heat stress
behavior
electroencephalography
electron microscope
hippocampus, electron, scanning transmission
