THE SUPRACHIASMATIC NUCLEI CONTAIN A TETRODOTOXIN-RESISTANT CIRCADIAN PACEMAKER
THE SUPRACHIASMATIC NUCLEI CONTAIN A TETRODOTOXIN-RESISTANT CIRCADIAN PACEMAKER
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DOI：
10.1073/pnas.84.6.1694
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发表时间：
1987-03-01
影响因子：
11.1
通讯作者：
MORTON, MT
中科院分区：
文献类型：
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作者：
SCHWARTZ, WJ;GROSS, RA;MORTON, MT
将河豚毒素连续14d注入未麻醉和自由支配的大鼠视交叉上核。尽管毒素可逆地阻断了起搏器携带的输入通路和表达昼夜节律的输出通路的功能，但核内昼夜节律起搏器的内部计时机制继续振荡，不受这种处理的影响。因此，钠离子依赖的动作电位似乎是携带和表达明显的昼夜节律所必需的，但它们似乎不是起搏器保持准确时间所必需的。本文提出的实验方法是有用的，因为它允许系统地评估和区分哺乳动物体内昼夜节律计时系统的输入、起搏器和输出组件。
Tetrodotoxin was infused into the suprachiasmatic nuclei of unanesthetized and unrestrained rats continuously for 14 days. The internal timekeeping mechanism of the circadian pacemaker in the nuclei continued to oscillate unaffected by this treatment, although the toxin reversibly blocked function of both the input pathway for pacemaker entrainment and an output pathway for expression of the circadian drinking rhythm. Thus, Na+-dependent action potentials appear necessary for entrainment and expression of overt circadian rhythms, but they do not seem necessary for the pacemaker to keep accurate time. The experimental approach presented in this paper is useful because it allows systematic assessment and distinction of the input, pacemaker, and output components of a mammalian circadian timekeeping system in vivo.