The olfactory tubercle (OT), an important nucleus in processing sensory information, has been reported to change cortical activity under odor. However, little is known about the physiological role and mechanism of the OT in sleep-wake regulation. The OT expresses abundant adenosine A2A receptors (A2ARs), which are important in sleep regulation. Therefore, we hypothesized that the OT regulates sleep via A2ARs. This study examined sleep-wake profiles through electroencephalography and electromyography recordings with pharmacological and chemogenetic manipulations in freely moving rodents. Compared with their controls, activation of OT A2ARs pharmacologically and OT A2AR neurons via chemogenetics increased non-rapid eye movement sleep for 5 and 3 h, respectively, while blockade of A2ARs decreased non-rapid eye movement sleep. Tracing and electrophysiological studies showed OT A2AR neurons projected to the ventral pallidum and lateral hypothalamus, forming inhibitory innervations. Together, these findings indicate that A2ARs in the OT play an important role in sleep regulation.

中文翻译：

---

嗅结节中腺苷A2A受体的激活促进了啮齿动物的睡眠。

嗅觉结节（OT）是处理感官信息的重要核，据报道会改变气味下的皮层活动。然而，关于OT在睡眠觉醒调节中的生理作用和机制知之甚少。OT表达丰富的腺苷A2A受体（A2ARs），这在睡眠调节中很重要。因此，我们假设OT通过A2AR调节睡眠。这项研究通过脑电图和肌电图记录，通过药理学和化学发生学方法，对自由活动的啮齿动物进行了睡眠-觉醒特征的检查。与他们的对照相比，通过药理学激活OT A2ARs和OT A2AR神经元的激活分别增加了非快速眼动睡眠5 h和3 h，而阻断A2ARs则降低了非快速眼动睡眠。示踪和电生理研究表明，OT A2AR神经元投射到腹侧苍白球和下丘脑外侧，形成抑制性神经支配。总之，这些发现表明OT中的A2AR在睡眠调节中起重要作用。