Mehdi Sadeghi, Fatemeh Zareie, Masoumeh Gholami, Farzaneh Nazari-Serenjeh, Mohadeseh Ghalandari-Shamami, Abbas Haghparast
{"title":"Contribution of the intra-hippocampal orexin system in the regulation of restraint stress response to pain-related behaviors in the formalin test.","authors":"Mehdi Sadeghi, Fatemeh Zareie, Masoumeh Gholami, Farzaneh Nazari-Serenjeh, Mohadeseh Ghalandari-Shamami, Abbas Haghparast","doi":"10.1097/FBP.0000000000000755","DOIUrl":null,"url":null,"abstract":"<p><p>Stress-induced antinociception (SIA) is due to the activation of several neural pathways and neurotransmitters that often suppress pain perception. Studies have shown that the orexin neuropeptide system is essential in pain modulation. Therefore, this study aimed to investigate the role of orexinergic receptors in the hippocampal CA1 region in modulating SIA response during the formalin test as an animal model of inflammatory pain. The orexin-1 receptor (OX1r) antagonist, SB334867, at 1, 3, 10, and 30 nmol or TCS OX2 29 as an orexin-2 receptor (OX2r) antagonist at the same doses were microinjected into the CA1 region in rats. Five minutes later, rats were exposed to restraint stress (RS) for 3 h, and pain-related behaviors were monitored in 5-min blocks for the 60-min test period in the formalin test. Results showed that applying RS for 3 h reduced pain responses in the early and late phases of the formalin test. The main findings showed that intra-CA1 injection of orexin receptor antagonists reduced the antinociception caused by stress in both phases of the formalin test. In addition, the contribution of OX2r in mediating the antinociceptive effect of stress was more prominent than that of OX1r in the early phase of the formalin test. However, in the late phase, both receptors worked similarly. Accordingly, the orexin system and its two receptors in the CA1 region of the hippocampus regulate SIA response to this animal model of pain in formalin test.</p>","PeriodicalId":8832,"journal":{"name":"Behavioural Pharmacology","volume":null,"pages":null},"PeriodicalIF":1.6000,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Behavioural Pharmacology","FirstCategoryId":"102","ListUrlMain":"https://doi.org/10.1097/FBP.0000000000000755","RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2023/11/7 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"BEHAVIORAL SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Stress-induced antinociception (SIA) is due to the activation of several neural pathways and neurotransmitters that often suppress pain perception. Studies have shown that the orexin neuropeptide system is essential in pain modulation. Therefore, this study aimed to investigate the role of orexinergic receptors in the hippocampal CA1 region in modulating SIA response during the formalin test as an animal model of inflammatory pain. The orexin-1 receptor (OX1r) antagonist, SB334867, at 1, 3, 10, and 30 nmol or TCS OX2 29 as an orexin-2 receptor (OX2r) antagonist at the same doses were microinjected into the CA1 region in rats. Five minutes later, rats were exposed to restraint stress (RS) for 3 h, and pain-related behaviors were monitored in 5-min blocks for the 60-min test period in the formalin test. Results showed that applying RS for 3 h reduced pain responses in the early and late phases of the formalin test. The main findings showed that intra-CA1 injection of orexin receptor antagonists reduced the antinociception caused by stress in both phases of the formalin test. In addition, the contribution of OX2r in mediating the antinociceptive effect of stress was more prominent than that of OX1r in the early phase of the formalin test. However, in the late phase, both receptors worked similarly. Accordingly, the orexin system and its two receptors in the CA1 region of the hippocampus regulate SIA response to this animal model of pain in formalin test.
期刊介绍:
Behavioural Pharmacology accepts original full and short research reports in diverse areas ranging from ethopharmacology to the pharmacology of schedule-controlled operant behaviour, provided that their primary focus is behavioural. Suitable topics include drug, chemical and hormonal effects on behaviour, the neurochemical mechanisms under-lying behaviour, and behavioural methods for the study of drug action. Both animal and human studies are welcome; however, studies reporting neurochemical data should have a predominantly behavioural focus, and human studies should not consist exclusively of clinical trials or case reports. Preference is given to studies that demonstrate and develop the potential of behavioural methods, and to papers reporting findings of direct relevance to clinical problems. Papers making a significant theoretical contribution are particularly welcome and, where possible and merited, space is made available for authors to explore fully the theoretical implications of their findings. Reviews of an area of the literature or at an appropriate stage in the development of an author’s own work are welcome. Commentaries in areas of current interest are also considered for publication, as are Reviews and Commentaries in areas outside behavioural pharmacology, but of importance and interest to behavioural pharmacologists. Behavioural Pharmacology publishes frequent Special Issues on current hot topics. The editors welcome correspondence about whether a paper in preparation might be suitable for inclusion in a Special Issue.