Daily electrical activity in the master circadian clock of a diurnal mammal.
Daily electrical activity in the master circadian clock of a diurnal mammal.
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DOI：
10.7554/elife.68179
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发表时间：
2021-11-30
期刊：
影响因子：
7.7
通讯作者：
Belle MD
中科院分区：
文献类型：
--
作者：
Bano-Otalora B;Moye MJ;Brown T;Lucas RJ;Diekman CO;Belle MD
哺乳动物的昼夜节律是由视交叉上核（SCN）内的中央时钟协调的。我们对SCN活动的电生理学基础的理解绝大多数来自少数夜间活动的啮齿动物，而这些在白天活动的动物中保留的程度仍不清楚。在这里，我们记录了自发的和诱发的电活动的单个SCN神经元在昼夜啮齿动物小横纹鼠，并开发了尖端的数据同化和数学建模方法，以揭示潜在的离子机制。在夜行性啮齿动物中，R. pumilio SCN神经元在白天更兴奋。与此相反，R. pumilio神经元包括一个突出的抑制反应，是不存在于SCN的夜间啮齿动物。我们的模型显示，随后的实验证实了瞬时阈下A型钾通道是这种反应的主要决定因素，并表明这种离子机制在优化SCN功能以适应R中起着关键作用。pumilio的昼夜壁龛。
Circadian rhythms in mammals are orchestrated by a central clock within the suprachiasmatic nuclei (SCN). Our understanding of the electrophysiological basis of SCN activity comes overwhelmingly from a small number of nocturnal rodent species, and the extent to which these are retained in day-active animals remains unclear. Here, we recorded the spontaneous and evoked electrical activity of single SCN neurons in the diurnal rodent Rhabdomys pumilio, and developed cutting-edge data assimilation and mathematical modeling approaches to uncover the underlying ionic mechanisms. As in nocturnal rodents, R. pumilio SCN neurons were more excited during daytime hours. By contrast, the evoked activity of R. pumilio neurons included a prominent suppressive response that is not present in the SCN of nocturnal rodents. Our modeling revealed and subsequent experiments confirmed transient subthreshold A-type potassium channels as the primary determinant of this response, and suggest a key role for this ionic mechanism in optimizing SCN function to accommodate R. pumilio’s diurnal niche.