Astrocytes in the rostral ventromedial medulla contribute to the maintenance of oro‐facial hyperalgesia induced by late removal of dental occlusal interference
| Autor: | Shan-Shan Bai, Yun Liu, Kai-Yuan Fu, Qiu-Fei Xie, Barry J. Sessle, Si-Yi Mo, Ye Cao, Xiaoxiang Xu |
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| Rok vydání: | 2021 |
| Předmět: |
Male
medicine.medical_specialty Orofacial pain Carbenoxolone Rats Sprague-Dawley 03 medical and health sciences 0302 clinical medicine Internal medicine medicine Animals General Dentistry Microinjection Medulla Oblongata Glial fibrillary acidic protein biology business.industry 030206 dentistry Rats medicine.anatomical_structure Endocrinology Nociception Hyperalgesia Astrocytes biology.protein Rostral ventromedial medulla medicine.symptom business 030217 neurology & neurosurgery medicine.drug Astrocyte |
| Zdroj: | Journal of Oral Rehabilitation. 49:207-218 |
| ISSN: | 1365-2842 0305-182X |
| Popis: | Background Astrocytes in the rostral ventromedial medulla (RVM) contribute to descending pain modulation, but their role in oro-facial pain induced by persistent experimental dental occlusal interference (PEOI) or following EOI removal (REOI) is unknown. Objective To explore the involvement of RVM astrocytes in PEOI-induced oro-facial hyperalgesia or its maintenance following REOI. Methods Male rats were randomly assigned into five groups: sham-EOI, postoperative day 6 and 14 of PEOI (PEOI 6 d and PEOI 14 d), postoperative day 6 following REOI on day 3 (REOI 3 d) and postoperative day 14 following REOI on day 8 (REOI 8 d). The nociceptive head withdrawal threshold (HWT) and activities of RVM ON- or OFF-cells were recorded before and after intra-RVM astrocyte gap junction blocker carbenoxolone (CBX) microinjection. RVM astrocytes were labelled immunohistochemically with glial fibrillary acidic protein (GFAP) and analysed semi-quantitatively. Results Persistent experimental dental occlusal interference-induced oro-facial hyperalgesia, as reflected in decreased HWTs, was partially inhibited by REOI at day 3 but not at day 8 after EOI placement. Increased GFAP-staining area occurred only in REOI 8 d group in which CBX could inhibit the maintained hyperalgesia; CBX was ineffective in inhibiting hyperalgesia in PEOI 14 d group. OFF-cell activities showed no change, but the spontaneous activity and responses of ON-cells were significantly enhanced that could be suppressed by CBX in REOI 8 d group. Conclusion Rostral ventromedial medulla astrocytes may not participate in PEOI-induced oro-facial hyperalgesia or hyperalgesia inhibition by early REOI but are involved in the maintenance of oro-facial hyperalgesia by late REOI. |
| Databáze: | OpenAIRE |
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