The dorsomedial hypothalamic nucleus is not necessary for food-anticipatory circadian rhythms of behavior, temperature or clock gene expression in mice
The dorsomedial hypothalamic nucleus is not necessary for food-anticipatory circadian rhythms of behavior, temperature or clock gene expression in mice
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DOI：
10.1111/j.1460-9568.2009.06697.x
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发表时间：
2009-04-01
影响因子：
3.4
通讯作者：
Shibata, Shigenobu
中科院分区：
文献类型：
--
作者：
Moriya, Takahiro;Aida, Reiko;Shibata, Shigenobu
哺乳动物的昼夜节律是由下丘脑视交叉上核的昼夜节律起搏器和大脑和身体其他部位的食物振荡器调节的。下丘脑背内侧核（DMH）被认为是驱动食物预期昼夜节律的振荡器的场所，但这是有争议的。为了进一步评估这一假设，我们测量了完整和DMH消融小鼠的时钟基因，温度和活动节律。一个单一的4小时的中午喂养后，过夜快速诱导mPer 1和mPer 2 mRNA表达的DMH，弓状核，孤束核和最后区，并重置每日的节奏mPer 1，mPer 2和mBMAL 1的DMH，弓状和新皮质。这些节奏持续2天的食物剥夺后，12天的计划日间喂养。DMH mPer 1和mPer 2的急性诱导是N-甲基-d-天冬氨酸（NMDA）受体依赖性的，而限制喂养6天后的节律性表达则不是。热DMH损伤并不影响急性诱导或节律性表达的时钟基因在其他脑区在计划的白天喂养。DMH病变衰减平均每日活动水平和活动性，但不影响食物预期的活动和体温的节奏，无论是在光暗或恒定的黑暗。这些结果证实，DMH和其他大脑区域表达昼夜节律基因节律敏感的白天喂养时间表，但不支持的假设，DMH振荡驱动食物预期的行为或温度的节奏。
Circadian rhythms in mammals are regulated by a light-entrainable circadian pacemaker in the hypothalamic suprachiasmatic nucleus and food-entrainable oscillators located elsewhere in the brain and body. The dorsomedial hypothalamic nucleus (DMH) has been proposed to be the site of oscillators driving food-anticipatory circadian rhythms, but this is controversial. To further evaluate this hypothesis, we measured clock gene, temperature and activity rhythms in intact and DMH-ablated mice. A single 4-h midday feeding after an overnight fast induced mPer1 and mPer2 mRNA expression in the DMH, arcuate nucleus, nucleus of the solitary tract and area postrema, and reset daily rhythms of mPer1, mPer2 and mBMAL1 in the DMH, arcuate and neocortex. These rhythms persisted during 2 days of food deprivation after 12 days of scheduled daytime feeding. Acute induction of DMH mPer1 and mPer2 was N-methyl-d-aspartate (NMDA) receptor-dependent, whereas rhythmic expression after 6 days of restricted feeding was not. Thermal DMH lesions did not affect acute induction or rhythmic expression of clock genes in other brain regions in response to scheduled daytime feeding. DMH lesions attenuated mean daily activity levels and nocturnality but did not affect food-anticipatory rhythms of activity and body temperature in either light-dark or constant darkness. These results confirm that the DMH and other brain regions express circadian clock gene rhythms sensitive to daytime feeding schedules, but do not support the hypothesis that DMH oscillations drive food-anticipatory behavioral or temperature rhythms.