The effect of urethane and MS-222 anesthesia on the electric organ discharge of the weakly electric fish Apteronotus leptorhynchus
The effect of urethane and MS-222 anesthesia on the electric organ discharge of the weakly electric fish Apteronotus leptorhynchus
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DOI：
10.1007/s00359-022-01606-6
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发表时间：
2023-02-17
影响因子：
2.1
通讯作者：
Zupanc，Guenther K. H.
中科院分区：
文献类型：
--
作者：
Eske，Annika I.;Lehotzky，David;Zupanc，Guenther K. H.
乌拉坦和MS-222是广泛用于全身麻醉的药物，然而，除了导致昏迷状态外，人们对它们的神经生理影响知之甚少。为了研究这些效应，我们开发了一种体内测试方法，使用弱电鱼类Apteronotus Leptorhynchus的电子器官放电(EOD)作为起搏核神经输出的替代。脑干核团的振荡神经活动以一对一的方式驱动鱼的排泄物。乌拉坦或MS-222麻醉后，EOD频率显著降低，持续时间长达3h。此外，两种药物均可使EOD的瞬变调制产生不同程度的增加，称为啁啾。EOD频率的降低可以通过乌拉坦对神经传递的调制作用和MS-222对电压门控钠通道的阻断来解释，两者都位于控制起搏核神经振荡的电路中。本研究表明，乌拉坦和MS-222对中枢神经系统内的神经活动和相关动物的行为有显著影响。这要求在全身麻醉下进行神经生理学实验并解释其结果时要谨慎。
Urethane and MS-222 are agents widely employed for general anesthesia, yet, besides inducing a state of unconsciousness, little is known about their neurophysiological effects. To investigate these effects, we developed an in vivo assay using the electric organ discharge (EOD) of the weakly electric fishApteronotus leptorhynchusas a proxy for the neural output of the pacemaker nucleus. The oscillatory neural activity of this brainstem nucleus drives the fish’s EOD in a one-to-one fashion. Anesthesia induced by urethane or MS-222 resulted in pronounced decreases of the EOD frequency, which lasted for up to 3 h. In addition, each of the two agents caused a manifold increase in the generation of transient modulations of the EOD known as chirps. The reduction in EOD frequency can be explained by the modulatory effect of urethane on neurotransmission, and by the blocking of voltage-gated sodium channels by MS-222, both within the circuitry controlling the neural oscillations of the pacemaker nucleus. The present study demonstrates a marked effect of urethane and MS-222 on neural activity within the central nervous system and on the associated animal’s behavior. This calls for caution when conducting neurophysiological experiments under general anesthesia and interpreting their results.