PDF(Pubmed)
Abstract：
Anoxia in the mammalian brain leads to hyper-excitability and cell death; however, this cascade of events does not occur in the anoxia-tolerant brain of the western painted turtle, Chrysemys picta belli. The painted turtle has become an important anoxia-tolerant model to study brain, heart, and liver function in the absence of oxygen, but being anoxia-tolerant likely means that decapitation alone is not a suitable method of euthanasia. Many anesthetics have long-term effects on ion channels and are not appropriate for same day experimentation. Using whole-cell electrophysiological techniques, we examine the effects of the anesthetic, Alfaxalone, on pyramidal cell action potential amplitude, threshold, rise and decay time, width, frequency, whole cell conductance, and evoked GABAA receptors currents to determine if any of these characteristics are altered with the use of Alfaxalone for animal sedation. We find that Alfaxalone has no long-term impact on action potential parameters or whole-cell conductance. When acutely applied to naïve tissue, Alfaxalone did lengthen GABAA receptor current decay rates by 1.5-fold. Following whole-animal sedation with Alfaxalone, evoked whole cell GABAA receptor current decay rates displayed an increasing trend with 1 and 2 hours after brain sheet preparation, but showed no significant change after a 3-hour washout period. Therefore, we conclude that Alfaxalone is a suitable anesthetic for same day use in electrophysiological studies in western painted turtle brain tissue.
摘要：
哺乳动物大脑中的缺氧导致过度兴奋和细胞死亡；然而，这种级联事件不会发生在西方彩龟的耐缺氧大脑中，ChrysemysPictaBelli.彩龟已成为研究大脑的重要耐缺氧模型，心,在没有氧气的情况下的肝功能，但是耐缺氧可能意味着单独斩首不是安乐死的合适方法。许多麻醉剂对离子通道有长期影响，不适合当天的实验。使用全细胞电生理技术，我们检查麻醉剂的效果，Alfaxalone,锥体细胞动作电位振幅，阈值，上升和衰减时间，宽度,频率,全细胞电导，并诱发GABAA受体电流，以确定使用Alfaxalone进行动物镇静是否改变了这些特征。我们发现Alfaxalone对动作电位参数或全细胞电导没有长期影响。当急性应用于幼稚组织时，Alfaxalone确实将GABAA受体电流衰减率延长了1.5倍。在用Alfaxalone镇静整个动物之后,诱发的全细胞GABAA受体电流衰减率在脑片制备后1和2小时显示出增加的趋势，但在3小时的冲洗期后没有显着变化。因此,我们得出的结论是，Alfaxalone是一种适合在西方彩绘乌龟脑组织中进行电生理研究的当天使用的麻醉剂。
