Gent Thomas C, Vyssotski Alexei L, Detotto Carlotta, Isler Sarah, Wehrle Martin, Bettschart-Wolfensberger Regula
Section of Anaesthesiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
Institute for Neuroinformatics, University of Zürich and ETH Zurich, Zurich, Switzerland.
Vet Anaesth Analg. 2019 Sep;46(5):652-657. doi: 10.1016/j.vaa.2019.04.002. Epub 2019 Apr 11.
To compare behavioural and electrophysiological variables of mice undergoing gas euthanasia with either xenon (Xe) or carbon dioxide (CO).
Single animals chronically instrumented for electroencephalography (EEG) recording were randomized to undergo euthanasia with either CO or Xe (n = 6 animals per group).
Twelve adult (>6 weeks old) male C57Bl6/n mice.
Mice were surgically instrumented with EEG and electromyogram electrodes. Following a 7-day recovery period, animals were placed individually in a sealed chamber and a 5-minute baseline recorded in 21% O. Gas [100% Xe (n = 6) or 100% CO (n = 6)] was then added to the chamber at 30% chamber volume minute (2.8 L minute) until cessation of breathing. EEG, behaviour (jumping and freezing) and locomotion speed were recorded throughout.
Mice undergoing single gas euthanasia with Xe did not show jumping or freezing behaviours and had reduced locomotion speed compared to baseline, in contrast to CO, which resulted in increases in these variables. EEG recordings revealed sedative effects from Xe but heightened arousal from CO.
Our data suggest that Xe may be less aversive than CO when using a 30% chamber volume minute fill rate and could improve the welfare of mice undergoing gas euthanasia.
比较接受氙气（Xe）或二氧化碳（CO₂）气体安乐死的小鼠的行为和电生理变量。
将长期植入脑电图（EEG）记录仪器的单只动物随机分为接受CO₂或Xe安乐死的两组（每组n = 6只动物）。
12只成年（>6周龄）雄性C57Bl6/n小鼠。
通过手术给小鼠植入EEG和肌电图电极。经过7天的恢复期后，将动物单独置于密封舱中，并在21%氧气环境下记录5分钟的基线数据。然后以每分钟30%舱体容积（2.8升/分钟）的速度向舱内添加气体[100% Xe（n = 6）或100% CO₂（n = 6）]，直至呼吸停止。全程记录EEG、行为（跳跃和僵住）以及运动速度。
与CO₂相比，接受Xe单次气体安乐死的小鼠未表现出跳跃或僵住行为，且运动速度相较于基线有所降低，而CO₂则导致这些变量增加。EEG记录显示Xe有镇静作用，而CO₂会增强唤醒作用。
我们的数据表明，当以每分钟30%舱体容积的填充速率使用时，Xe可能比CO₂的厌恶程度更低，并且可能改善接受气体安乐死小鼠的福利。
