The Visual Systems Group, Division of Pediatric Ophthalmology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA.
Curr Biol. 2012 Oct 9;22(19):1851-7. doi: 10.1016/j.cub.2012.08.006. Epub 2012 Sep 13.
A daily body temperature rhythm (BTR) is critical for the maintenance of homeostasis in mammals. Whereas mammals use internal energy to regulate body temperature, ectotherms typically regulate body temperature behaviorally [1]. Some ectotherms maintain homeostasis via a daily temperature preference rhythm (TPR) [2], but the underlying mechanisms are largely unknown. Here, we show that Drosophila exhibit a daily circadian clock-dependent TPR that resembles mammalian BTR. Pacemaker neurons critical for locomotor activity are not necessary for TPR; instead, the dorsal neuron 2 s (DN2s), whose function was previously unknown, is sufficient. This indicates that TPR, like BTR, is controlled independently from locomotor activity. Therefore, the mechanisms controlling temperature fluctuations in fly TPR and mammalian BTR may share parallel features. Taken together, our results reveal the existence of a novel DN2-based circadian neural circuit that specifically regulates TPR; thus, understanding the mechanisms of TPR will shed new light on the function and neural control of circadian rhythms.
每日体温节律（BTR）对于哺乳动物的内稳态维持至关重要。哺乳动物利用内部能量来调节体温，而变温动物通常通过行为来调节体温[1]。一些变温动物通过每日温度偏好节律（TPR）来维持内稳态[2]，但其潜在机制在很大程度上尚不清楚。在这里，我们发现果蝇表现出一种类似于哺乳动物 BTR 的昼夜节律依赖性 TPR。对于运动活动至关重要的起搏器神经元对于 TPR 并非必需；相反，先前功能未知的背神经元 2s（DN2s）是足够的。这表明 TPR 与 BTR 一样，独立于运动活动而受到控制。因此，控制果蝇 TPR 和哺乳动物 BTR 中温度波动的机制可能具有相似的特征。总之，我们的研究结果揭示了一种基于新型 DN2 的昼夜节律神经回路的存在，该回路专门调节 TPR；因此，理解 TPR 的机制将为昼夜节律的功能和神经控制提供新的见解。
