Slow-wave sleep is controlled by the nucleus accumbens
側坐核による徐波睡眠の制御

Losing yourself in your favorite things without sleeping, or falling asleep during boring lectures — As humans, we often defy sleepiness and stay awake when attention is necessary, but also experience an inescapable desire to sleep in boring situations. The brain mechanisms governing the regulation of sleep by cognitive and emotional factors are not well understood. We found that a part of the brain that is associated with motivation and pleasure – the nucleus accumbens – also can produce sleep. The new findings may explain why we have the tendency to fall asleep in the absence of motivating stimuli, i.e., when bored. We used chemo-genetic and optical techniques to remotely control the activities of nucleus accumbens neurons and the behaviors they mediate. As a result, we discovered that nucleus accumbens neurons have an extremely strong ability to induce sleep that is indistinguishable from the major component of natural sleep, known as slow-wave sleep, as it is characterized by slow and high-voltage brain waves (Oishi Y, et al, Nat Commun, 8:734, 2017).

 面白い映画を観てつい夜更かししたり、退屈な講義を聴いて眠気に襲われることは誰しもが経験します。このような「モチベーション」の変化による睡眠制御の仕組みは、明らかではありません。

 我々は、モチベーションや快楽に関与する脳領域・側坐核に注目し、化学遺伝学および光遺伝学技術により神経活動を操作しました。その結果、側坐核の特定の神経群による強力な徐波睡眠(ノンレム睡眠;睡眠の主成分)誘発作用が見出されました。モチベーション刺激が無い時に眠くなるのは、側坐核の作用かもしれません (Oishi Y, et al, Nat Commun, 8:734, 2017)。

© 2017 by Lazarus Laboratory.