In this work we studied the impact of two widely used anesthetics on the electrical activity of auditory brainstem neurons during development. The spontaneous electrical activity in neonate rats of either sex was analyzed under the injectable mix of ketamine/xylazine (K/X mix) and the volatile anesthetic isoflurane (ISO). We used a ventral craniotomy in mechanically ventilated pups to carry out electrophysiology recordings in the superior olivary complex (SOC) between birth (postnatal day 0, P0) and P12. To characterize neuronal activity of single and ensembles of neurons, we performed patch clamp and multi-electrode experiments under different anesthetic conditions. Our results provide the first study that compares K/X mix and ISO in the same rodent species. We demonstrate that electrical activity of SOC neurons ramps up during development, and that the firing pattern of single units recorded in K/X mix was similar to that reported in ISO anesthetized rat pups. However, ISO displayed a large scatter on its suppressing effects on electrical activity when delivered at 1.5% in the presence or the absence of K/X mix. Taken together, our results shed light on the use of anesthetics for future studies to enable electrophysiology or optical imaging studies in-vivo to obtain functional information on the activity of medial olivochoclear neurons and their role in auditory development.

中文翻译：

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注射或挥发性麻醉下发作前上橄榄神经元自发电活动发展变化的特征

在这项工作中，我们研究了两种广泛使用的麻醉剂对发育过程中听觉脑干神经元电活动的影响。在氯胺酮/甲苯噻嗪的可注射混合物（K / X混合物）和挥发性麻醉剂异氟烷（ISO）的作用下，分析了两种性别的新生大鼠的自发电活动。我们在机械通气的幼仔中进行了开颅手术，以在出生（出生后第0天，P0）和P12之间的上橄榄复合体（SOC）中进行电生理记录。为了表征单个神经元和整个神经元的神经元活性，我们在不同的麻醉条件下进行了膜片钳和多电极实验。我们的结果提供了第一项研究，比较了相同啮齿动物中的K / X混合物和ISO。我们证明，SOC神经元的电活动在发育过程中逐渐增加，并且在K / X混合物中记录的单个单元的发射模式与在ISO麻醉的大鼠幼崽中报道的类似。但是，在有或没有K / X混合物的情况下，当以1.5％的浓度输送ISO时，ISO对电活性的抑制作用表现出很大的分散性。综上所述，我们的结果揭示了麻醉药在未来的研究中的应用，以使体内电生理学或光学成像研究能够获得有关内侧小卵核神经元活性及其在听觉发育中的作用的功能性信息。