Abstract：
Flatworms are among the best studied animal models for regeneration; however, they also represent an emerging opportunity to investigate other biological processes as well. For instance, flatworms are nocturnal and sleep during the day, a state that is regulated by sleep/wake history and the action of the sleep-promoting neurotransmitter gamma-aminobutyric acid (or GABA). Sleep is widespread across the animal kingdom, where it serves many nonexclusive functions. Notably, sleep saves energy by reducing metabolic rate and by not doing something more energetically taxing. Whether the conservation of energy is apparent in sleeping flatworms is unclear. We measured the oxygen consumption rate (OCR) of flatworms dosed with either (1) GABA (n = 29) which makes flatworms inactive or (2) dopamine (n = 20) which stimulates flatworms to move, or (3) day and night neurotransmitter-free controls (n = 28 and 27, respectively). While OCR did not differ between the day and night, flatworms treated with GABA used less oxygen than those treated with dopamine, and less than the day-time control. Thus, GABA affected flatworm physiology, ostensibly by enforcing energy-conserving sleep. Evidence that dopamine increased metabolism was less strong. This work broadens our understanding of flatworm physiology and expands the phylogenetic applicability of energy conservation as a function of sleep.
摘要：
扁虫是研究最好的再生动物模型之一；然而，它们也代表了研究其他生物过程的新兴机会。例如,扁虫是夜间活动的，白天睡觉，由睡眠/觉醒史和促进睡眠的神经递质γ-氨基丁酸（或GABA）的作用调节的状态。睡眠在整个动物界都很普遍，它提供许多非排他性功能。值得注意的是,睡眠通过降低代谢率和不做更多能量负担来节省能量。尚不清楚睡眠中的扁虫是否明显保持能量。我们测量了使用（1）GABA（n=29）使扁虫失活或（2）刺激扁虫移动的多巴胺（n=20）的扁虫的耗氧率（OCR），或（3）白天和夜间无神经递质的对照（分别为n=28和27）。虽然OCR在白天和黑夜之间没有区别，用GABA治疗的扁虫比用多巴胺治疗的扁虫消耗更少的氧气，少于白天的时间控制。因此，GABA影响扁虫的生理，表面上是通过强制节能睡眠。有证据表明多巴胺增加的新陈代谢强度较低。这项工作扩大了我们对扁虫生理学的理解，并扩大了能量守恒作为睡眠功能的系统发育适用性。
