Queensland Brain Institute, The University of Queensland, St Lucia, QLD, 4072, Australia.
Department of Neurological Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA.
Nat Commun. 2017 Nov 28;8(1):1815. doi: 10.1038/s41467-017-02024-y.
Sleep is a dynamic process comprising multiple stages, each associated with distinct electrophysiological properties and potentially serving different functions. While these phenomena are well described in vertebrates, it is unclear if invertebrates have distinct sleep stages. We perform local field potential (LFP) recordings on flies spontaneously sleeping, and compare their brain activity to flies induced to sleep using either genetic activation of sleep-promoting circuitry or the GABA agonist Gaboxadol. We find a transitional sleep stage associated with a 7-10 Hz oscillation in the central brain during spontaneous sleep. Oscillatory activity is also evident when we acutely activate sleep-promoting neurons in the dorsal fan-shaped body (dFB) of Drosophila. In contrast, sleep following Gaboxadol exposure is characterized by low-amplitude LFPs, during which dFB-induced effects are suppressed. Sleep in flies thus appears to involve at least two distinct stages: increased oscillatory activity, particularly during sleep induction, followed by desynchronized or decreased brain activity.
睡眠是一个动态的过程，由多个阶段组成，每个阶段都与独特的电生理特性相关联，并可能具有不同的功能。尽管这些现象在脊椎动物中已有详细描述，但无脊椎动物是否具有独特的睡眠阶段尚不清楚。我们对自然睡眠的果蝇进行局部场电位 (LFP) 记录，并将其大脑活动与通过遗传激活促进睡眠的电路或 GABA 激动剂 Gaboxadol 诱导睡眠的果蝇进行比较。我们发现，在自然睡眠过程中，中脑会出现与 7-10 Hz 振荡相关的过渡性睡眠阶段。当我们急性激活果蝇背扇形体 (dFB) 中的促进睡眠神经元时，也会出现振荡活动。相比之下，Gaboaxadol 暴露后的睡眠表现为低幅度 LFPs，在此期间，dFB 诱导的效应被抑制。因此，果蝇的睡眠似乎至少涉及两个不同的阶段：在诱导睡眠时，振荡活动增加，特别是在诱导睡眠时，然后是大脑活动去同步或减少。
