Franz Weber, …, Yang Dan* Control of REM sleep by ventral medulla GABAergic neurons. Nature 526:435–438 (2015) https://www.nature.com/articles/nature14979 の論文の要旨が非常にかっちりと組み立てられていて無駄も隙もない文章構成だと思ったので、分析してみます。以下、英文 分析　の順です

Rapid eye movement (REM) sleep 主題を最初の文の文頭において明示 is a distinct brain state characterized by activated electroencephalogram and complete skeletal muscle paralysis, and is associated with vivid dreams1,2,3. 主題の説明 Transection studies by Jouvet first demonstrated that the brainstem is both necessary and sufficient for REM sleep generation2, 既知の事柄の紹介 and the neural circuits in the pons have since 副詞（それ以来）介 been studied extensively4,5,6,7,8. 研究の潮流の紹介 The medulla also contains neurons that are active during REM sleep9,10,11,12,13, 既知の事柄の紹介 but whether they play a causal role in REM sleep generation remains unclear. 問題提起 Here we show that a GABAergic (γ-aminobutyric-acid-releasing) pathway originating from the ventral medulla powerfully promotes REM sleep in mice. 提起した問題に対する簡潔な答え（実験結果の要約） Optogenetic activation of ventral medulla GABAergic neurons rapidly and reliably initiated REM sleep episodes and prolonged their durations, whereas inactivating these neurons had the opposite effects. もう少し詳細な実験結果 Optrode recordings from channelrhodopsin-2-tagged ventral medulla GABAergic neurons showed that they were most active during REM sleep (REMmax), and during wakefulness they were preferentially active during eating and grooming. 同様の結論を導く別の実験結果 Furthermore, dual retrograde tracing showed that the rostral projections to the pons and midbrain and caudal projections to the spinal cord originate from separate ventral medulla neuron populations. 別の実験結果（先行研究とつながる重要な発見） Activating the rostral GABAergic projections was sufficient for both the induction and maintenance of REM sleep, 実験結果の簡潔な要約・結論 which are probably mediated in part by inhibition of REM-suppressing GABAergic neurons in the ventrolateral periaqueductal grey. 推測を交えた補足 These results identify a key component of the pontomedullary network controlling REM sleep. 意義、結論（抽象化した表現）The capability to induce REM sleep on command may offer a powerful tool for investigating its functions. 将来展望・研究領域への期待される波及効果