Department of Biology, University of South Dakota, Vermillion, SD 57069 USA; Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069 USA; Veterans Affairs Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD 57105 USA.
Department of Biology, University of South Dakota, Vermillion, SD 57069 USA; Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069 USA; Veterans Affairs Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD 57105 USA.
Brain Res. 2020 Mar 15;1731:146085. doi: 10.1016/j.brainres.2018.12.036. Epub 2018 Dec 24.
Hypothalmic orexin/hypocretin (Orx) neurons in the lateral and dorsomedial perifornical region (LH-DMH/PeF) innervate broadly throughout the brain, and receive similar inputs. This wide distribution, as well as two Orx peptides (Orx and Orx) and two Orx receptors (Orx and Orx) allow for functionally related but distinctive behavioral outcomes, that include arousal, sleep-wake regulation, food seeking, metabolism, feeding, reward, addiction, and learning. These are all motivational functions, and tie the orexin systems to anxiety and depression as well. We present evidence, that for affective behavior, Orx and Orx receptors appear to have opposing functions. The majority of research on anxiety- and depression-related outcomes has focused on Orx receptors, which appear to have primarily anxiogenic and pro-depressive actions. Although there is significant research suggesting contrary findings, the primary potential for pharmacotherapies linked to the Orx receptor is via antagonists to block anxious and depressive behavior. Dual orexin receptor antagonists have been approved for treatment of sleep disorders, and are likely candidates for adaptation for affect disorder treatments. However, we present evidence here that demonstrates the Orx receptors are anxiolytic and antidepressive. Using a new experimental pre-clinical model of anxious and depressive behavior stimulated by social stress and decision-making that produces two stable behavioral phenotypes, Escape/Resilient and Stay/Susceptible, we tested the effects of intracerebroventricular injections of Orx agonist and antagonist drugs. Over ten behavioral measures, we have demonstrated that Orx agonists promote resilience, as well as anxiolytic and antidepressive behavior. In contrast, Orx antagonists or knockdown kindle anxious and pro-depressive behavior plus increase susceptibility. The results suggest that the Orx receptor may be a useful target for pharmacotherapies to treat anxiety and depression.
下丘脑食欲素/下丘脑分泌素(Orx)神经元位于外侧和背内侧peri 穹窿区(LH-DMH/PeF),广泛分布于整个大脑,并接受相似的输入。这种广泛的分布,以及两种 Orx 肽(Orx 和 Orx)和两种 Orx 受体(Orx 和 Orx),使得功能相关但具有独特行为结果的可能性增加,包括觉醒、睡眠-觉醒调节、食物寻求、代谢、进食、奖励、成瘾和学习。这些都是动机功能,也将食欲素系统与焦虑和抑郁联系在一起。我们提供的证据表明,对于情感行为,Orx 和 Orx 受体似乎具有相反的功能。大多数关于焦虑和抑郁相关结果的研究都集中在 Orx 受体上,这些受体似乎主要具有焦虑和促抑郁作用。尽管有大量研究表明相反的发现,但与 Orx 受体相关的潜在药物治疗主要是通过拮抗剂来阻断焦虑和抑郁行为。双重食欲素受体拮抗剂已被批准用于治疗睡眠障碍,并且可能是适应情感障碍治疗的候选药物。然而,我们在这里提供的证据表明,Orx 受体具有抗焦虑和抗抑郁作用。使用一种新的实验性临床前焦虑和抑郁行为模型,该模型由社会压力和决策刺激引起,产生两种稳定的行为表型,逃避/恢复和停留/易感,我们测试了脑室注射 Orx 激动剂和拮抗剂药物的效果。通过十多项行为测量,我们证明了 Orx 激动剂可以促进恢复,以及抗焦虑和抗抑郁行为。相反,Orx 拮抗剂或敲低会引起焦虑和促抑郁行为,并增加易感性。结果表明,Orx 受体可能是治疗焦虑和抑郁的药物治疗的有用靶点。