Chavan, Parimal Ravindra Tokushima University
Shiuchi, Tetsuya Tokushima University Tokushima University Educator and Researcher Directory KAKEN Search Researchers
Shimizu, Noriyuki Tokushima University Tokushima University Educator and Researcher Directory KAKEN Search Researchers
Dalanon, Junhel Tokushima University
Okura, Kazuo Tokushima University Tokushima University Educator and Researcher Directory KAKEN Search Researchers
Séi, Hiroyoshi Tokushima University Tokushima University Educator and Researcher Directory KAKEN Search Researchers
Predictable chronic mild stress (PCMS)
Thesis or Dissertation
Aims: This study aimed to evaluate the involvement of the orexin system in predictable chronic mild stress (PCMS) and the effects of suvorexant, a dual orexin receptor antagonist, on nociceptive behavior in PCMS.
Materials and methods: Male C57BL/6 J mice were separated into various PCMS groups: a control group with sawdust on the floor of the rearing cage (C), a group with mesh wire on the floor (M), and a group with water just below the mesh wire (W). Activation of lateral hypothalamic orexin neurons was assessed using immunofluorescence. In another experiment, half of the mice in each group were administered an intraperitoneal injection of suvorexant (10 mg/kg), and the remaining mice were injected with the same amount of vehicle (normal saline). Thermal hyperalgesia was examined using tail immersion and hot plate tests, while mechanical hyperalgesia was investigated using the tail pinch test after 21 days of PCMS.
Key findings: Animals subjected to PCMS showed an increased percentage of activated orexin neurons in the lateral hypothalamic region after 21 days. Mice raised in the PCMS environment showed increased pain sensitivity in several pain tests; however, the symptoms were significantly reduced by suvorexant administration.
Significance: The findings revealed that PCMS activates hypothalamic orexin neuronal activity, and the use of suvorexant can help attenuate PCMS-induced thermal and mechanical hyperalgesia.
Brain Research Bulletin
|DOI (Published Version)
|URL ( Publisher's Version )
k3749_abstract.pdf 315 KB
k3749_review.pdf 44.1 KB
k3749_fulltext.pdf 2.94 MB
|MEXT report number
Doctor of Dental Science