在海底作业和高压医学中呼吸高压氧(HBO2)。然而,潜水员和患者呼吸HBO2会增加中枢神经系统氧毒性(CNS-OT)的风险,最终表现为产生心动过速和高血压的交感神经刺激,换气过度,最终导致全身性癫痫发作和心源性肺水肿.在这项研究中,我们已经检验了皮肤电活动(EDA)变化的假设,测量交感神经系统的激活,先于癫痫发作的大鼠呼吸5个大气压绝对(ATA)HBO2。无线电遥测和啮齿动物系绳设备适用于密封的高压舱内。拴系的大鼠在用空气或100%O2冲洗的通风动物室内自由移动。将动物室和高压室(空气)以约1个大气压/分钟并行加压。EDA活动与皮层脑电图(EEG)活动同时记录,核心体温,和环境压力。我们使用原始EDA(TVSymp)的时变频谱分析捕获了EDA的动力学,以前被开发作为人类交感神经紧张评估的工具,调整以检测CNS-OT癫痫发作前大鼠EDA的动态变化。结果表明,在HBO2引起的癫痫发作前,平均(±SD)1.9±1.6分钟,EDA记录得出的TVSymp值的幅度显着增加。这些结果,如果在人类身上得到证实,支持使用TVSymp活动的变化作为潜水员和患者即将发生和可能致命的癫痫发作的早期“生理标记”。
Hyperbaric oxygen (HBO2) is breathed during undersea operations and in hyperbaric medicine. However, breathing HBO2 by divers and patients increases the risk of central nervous system oxygen toxicity (CNS-OT), which ultimately manifests as sympathetic stimulation producing tachycardia and hypertension, hyperventilation, and ultimately generalized seizures and cardiogenic pulmonary edema. In this study, we have tested the hypothesis that changes in electrodermal activity (EDA), a measure of sympathetic nervous system activation, precedes seizures in rats breathing 5 atmospheres absolute (ATA) HBO2. Radio telemetry and a rodent tether apparatus were adapted for use inside a sealed hyperbaric chamber. The tethered rat was free to move inside a ventilated animal chamber that was flushed with air or 100% O2. The animal chamber and hyperbaric chamber (air) were pressurized in parallel at ~1 atmosphere/min. EDA activity was recorded simultaneously with cortical electroencephalogram (EEG) activity, core body temperature, and ambient pressure. We have captured the dynamics of EDA using time-varying spectral analysis of raw EDA (TVSymp), previously developed as a tool for sympathetic tone assessment in humans, adjusted to detect the dynamic changes of EDA in rats that occur prior to onset of CNS-OT seizures. The results show that a significant increase in the amplitude of TVSymp values derived from EDA recordings occurs on average (±SD) 1.9 ± 1.6 min before HBO2-induced seizures. These results, if corroborated in humans, support the use of changes in TVSymp activity as an early \"physio-marker\" of impending and potentially fatal seizures in divers and patients.