In a Rat Model of Night Work, Activity during the Normal Resting Phase Produces Desynchrony in the Hypothalamus
In a Rat Model of Night Work, Activity during the Normal Resting Phase Produces Desynchrony in the Hypothalamus
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DOI：
10.1177/0748730410383403
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发表时间：
2010-12-01
影响因子：
3.5
通讯作者：
Escobar, Carolina
中科院分区：
文献类型：
--
作者：
Salgado-Delgado, Roberto;Nadia, Saderi;Escobar, Carolina
外部周期和内部振荡器之间的内部同步性允许生理学适应动态平衡的周期性需求夜间工作和轮班工作导致外部时间线索和内部节奏之间的相位关系中断，也失去了振荡之间的内部一致性。和代谢变量周期异相仍然不清楚ID是起源于外周还是中枢水平。为了确定下丘脑振荡器在ID中的可能作用，我们用大鼠“夜间工作”模型研究了下丘脑的活动和时钟基因表达的每日节律。这项研究提供了证据，证明在正常休息期的觉醒和活动导致c-Fos和PER 1在下丘脑弓状核和背内侧核的节律性变化，两者都与代谢和睡眠/觉醒周期的调节有关。此外，穹窿周围区的orexin（ORX）阳性神经元和c-Fos的数量在工作期间增加，这表明在这个脑区域中由预定的活动诱导的活动的相关转换，然而，ORX阳性细胞中c-Fos的共定位没有增加。相反，视交叉上核和室旁核保持锁定于光/暗周期，导致下丘脑中的ID目前的数据表明ID已经发生在SCN的第一输出投射的水平，将时间信号传递到其他大脑区域和外围的中继核团
Internal synchrony among external cycles and Internal oscillators allows adaptation of physiology to cyclic demands for homeostasis Night work and shift work lead to a disrupted phase relationship between external time cues and internal rhythms, also losing internal coherence among oscillations This process results m internal desynchrony (ID) in which behavioral, hormonal, and metabolic variables cycle out of phase It is still not clear whether ID originates at a peripheral or at a central level In order to determine the possible role of hypothalamic oscillators in ID, we explored with a rat model of "night work" daily rhythms of activity and clock gene expression m the hypothalamus This study provides evidence that wakefulness and activity during the normal resting phase lead to a shift in the diurnal rhythms of c-Fos and induce a rhythm of PER1 m the arcuate and dorsomedial nucleus of the hypothalamus, both associated with metabolism and regulation of the sleep/wake cycle Moreover, the number of orexin (ORX)-positive neurons and c-Fos in the perifornical area increased during the working period, suggesting a relevant switch of activity in this brain region induced by the scheduled activity, however, the colocalization of c-Fos in ORX-positive cells was not increased In contrast, the suprachiasmatic nucleus and the paraventricular nucleus remained locked to the light/dark cycle, resulting in ID in the hypothalamus Present data suggest that ID occurs already at the level of the first output projections from the SCN, relaying nuclei that transmit temporal signals to other brain areas and to the periphery