The arousal effect of caffeine

The sleeping habits of humans are unique in the sense that we often defy sleep and stay awake for occupational and recreational reasons or other life-style choices, despite experiencing fatigue during that time. The motivation to defy sleep and stay awake for a wide range of life-style choices is often accompanied by the use of psychoactive substances, most prominently caffeine. Our laboratory discovered that caffeine causes wakefulness through inhibiting the activity of adenosine, one of the most potent sleep-promoting neuromodulators, at adenosine A2A receptors (A2AR) in the nucleus accumbens - a brain region traditionally associated with drug addiction and motivational behavior (Lazarus M, et al., J Neurosci, 31:10067–10075, 2011).

 コーヒーやお茶などに含まれるカフェインは世界で最もよく摂取される向精神物質のひとつであり、その覚醒効果がよく知られています。そのメカニズムは長らく謎でしたが、我々は最近、薬物依存や動機付け行動に重要とされる脳部位・側坐核を介して、カフェインが覚醒効果を示すことを見出しました (Lazarus M, et al., J Neurosci, 31:10067–10075, 2011)。

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