School of Pharmacy, Pharmacology Unit, University of Camerino, Camerino 62032, Italy, Institute of Psychopharmacology at the Central Institute of Mental Health, Medical Faculty Mannheim/University of Heidelberg, Heidelberg 68159, Germany, Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, California 92037, and National Institutes of Health/National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892-1108.
J Neurosci. 2014 Jan 8;34(2):363-72. doi: 10.1523/JNEUROSCI.2400-13.2014.
Corticotropin releasing factor (CRF) is the primary mediator of stress responses, and nociceptin/orphanin FQ (N/OFQ) plays an important role in the modulation of these stress responses. Thus, in this multidisciplinary study, we explored the relationship between the N/OFQ and the CRF systems in response to stress. Using in situ hybridization (ISH), we assessed the effect of body restraint stress on the gene expression of CRF and N/OFQ-related genes in various subdivisions of the amygdala, a critical brain structure involved in the modulation of stress response and anxiety-like behaviors. We found a selective upregulation of the NOP and downregulation of the CRF1 receptor transcripts in the CeA and in the BLA after body restraint. Thus, we performed intracellular electrophysiological recordings of GABAA-mediated IPSPs in the central nucleus of the amygdala (CeA) to explore functional interactions between CRF and N/OFQ systems in this brain region. Acute application of CRF significantly increased IPSPs in the CeA, and this enhancement was blocked by N/OFQ. Importantly, in stress-restraint rats, baseline CeA GABAergic responses were elevated and N/OFQ exerted a larger inhibition of IPSPs compared with unrestraint rats. The NOP antagonist [Nphe1]-nociceptin(1-13)NH2 increased the IPSP amplitudes in restraint rats but not in unrestraint rats, suggesting a functional recruitment of the N/OFQ system after acute stress. Finally, we evaluated the anxiety-like response in rats subjected to restraint stress and nonrestraint rats after N/OFQ microinjection into the CeA. Intra-CeA injections of N/OFQ significantly and selectively reduced anxiety-like behavior in restraint rats in the elevated plus maze. These combined results demonstrate that acute stress increases N/OFQ systems in the CeA and that N/OFQ has antistress properties.
促肾上腺皮质释放因子（CRF）是应激反应的主要介质，孤啡肽/孤啡肽（N/OFQ）在调节这些应激反应中起着重要作用。因此，在这项多学科研究中，我们探讨了 N/OFQ 与 CRF 系统在应激反应中的关系。我们使用原位杂交（ISH）技术评估了躯体束缚应激对杏仁核不同亚区中 CRF 和 N/OFQ 相关基因表达的影响，杏仁核是参与调节应激反应和焦虑样行为的关键脑结构。我们发现，躯体束缚后，CeA 和 BLA 中的 NOP 表达上调，CRF1 受体转录物表达下调。因此，我们在杏仁核中央核（CeA）中进行了 GABAA 介导的 IPSP 的细胞内电生理记录，以探索该脑区中 CRF 和 N/OFQ 系统之间的功能相互作用。急性应用 CRF 可显著增加 CeA 中的 IPSP，且这种增强作用可被 N/OFQ 阻断。重要的是，在应激束缚大鼠中，CeA 中的基底 GABA 能反应升高，并且 N/OFQ 对 IPSP 的抑制作用比非束缚大鼠更大。NOP 拮抗剂[Nphe1]-孤啡肽（1-13）NH2 在束缚大鼠中增加 IPSP 幅度，但在非束缚大鼠中没有增加，这表明急性应激后 N/OFQ 系统的功能募集。最后，我们在 CeA 中注射 N/OFQ 后，评估了束缚应激大鼠和非束缚大鼠的焦虑样反应。CeA 内注射 N/OFQ 可显著选择性地降低束缚大鼠在高架十字迷宫中的焦虑样行为。这些综合结果表明，急性应激会增加 CeA 中的 N/OFQ 系统，并且 N/OFQ 具有抗应激特性。
