Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA.
Int J Hyperthermia. 2011;27(4):353-73. doi: 10.3109/02656736.2010.550905.
This review focuses upon the past 8 years of research on hyperthermic effects on behavior. Heat stress and heat stoke become severe conditions when body temperatures exceed 40°C as this can lead to delirium, convulsions, coma, and death. The animal literature indicates that hyperthermia can increase glutamatergic and decrease GABAergic neurotransmission. Interestingly, µ-opiate receptor antagonists can attenuate the morphological and biochemical changes in brain, as well as, ameliorate some behavioral deficits induced by heart stress. In humans, heat stress can produce detrimental effects on motor and cognitive performance. Since most cognitive tasks require a motor response, some cognitive deficiencies may be attributed to decreased motor performance. Although hyperthermia may exert more deleterious effects on complex than simple cognitive tasks, systematic studies are needed to examine the effects of different levels and durations of hyperthermia (irrespective of dehydration) on cognition. Additionally, body temperatures should be carefully monitored where controls are run for baseline or brief exposures to a hyperthermic environment. Acute radiofrequency exposure can disrupt behavior when body temperatures increase >1°C with whole body SAR between 3.2-8.4 W/kg and time-averaged power densities at 8-140 mW/cm(2). Effects of lower levels of radiation are conflicting and some experiments fail to replicate even with the original investigators. This suggests either that brief exposure to the radiation is at a threshold where some individuals are affected while others are not, or that these levels are innocuous. Nevertheless, thermal changes appear to account for almost all of the behavioral effects reported.
这篇综述重点关注了过去 8 年关于热效应对行为影响的研究。当体温超过 40°C 时，热应激和中暑会变得严重，因为这可能导致谵妄、抽搐、昏迷和死亡。动物文献表明，高温会增加谷氨酸能神经传递，减少 GABA 能神经传递。有趣的是，μ-阿片受体拮抗剂可以减轻大脑的形态和生化变化，并改善热应激引起的一些行为缺陷。在人类中，热应激会对运动和认知表现产生有害影响。由于大多数认知任务都需要运动反应，因此一些认知缺陷可能归因于运动表现下降。尽管高温可能对复杂认知任务的影响大于简单认知任务，但仍需要系统研究不同程度和持续时间的高温（不包括脱水）对认知的影响。此外，在进行基础或短暂暴露于高温环境的对照实验时，应仔细监测体温。当体温升高 >1°C 且全身 SAR 在 3.2-8.4 W/kg 之间，且时间平均功率密度在 8-140 mW/cm(2) 时，急性射频辐射会扰乱行为。较低水平辐射的影响存在争议，一些实验甚至无法复制原始研究者的结果。这表明，短暂暴露于辐射可能处于一个阈值，一些人受到影响，而另一些人则不受影响，或者这些水平是无害的。然而，热变化似乎解释了报告的几乎所有行为影响。
