Avaliação da ativação microglial no bulbo rostroventromedial (RVM) durante a vigência de dor neuropática orofacial induzida pela constrição do nervo infra-orbital: revisão sistemática

• Autor(a) principal: Okumura, Marlice Hayumi Theles [UNESP]
• Data de Publicação: 2015
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/149703; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2017-01-31/000867966.pdf
• topic: Dor facial; Microglia; Ratos; Facial pain

The pathophysiology of orofacial neuropathic pain is poorly understood, limiting their treatment. Studies demonstrate changes in endogenous pain modulation system as one of those responsible for the maintenance of neuropathic pain. The rostral ventromedial medulla (RVM) is among the main areas responsible for pain modulation. For a long time, the pain was seen only as reflect of the activity of neurons. However, in recent years, evidence suggests an effective participation of glial cells, especially in neuropathic pain. The aim of this study was to evaluate the pattern of microglial activation in RVM after constriction of the infra orbital nerve (IoN). Fifty four rats were distributed into three groups: CCI, CTL2 and CTL1. In CCI group, we accessed the infra orbital nerve (IoN) surgically, and two ligature (catgut chrome wire) were installed around it, to result in neuropathic pain. In CTL2 group, we only accessed the IoN surgically (sham-operated control group). While in CTL1 group no procedure was executed (control group intact). It was used facial grooming behavioral test after thermal stimulation (cold) in the region of adjacent vibrissae to validate the chronic constriction of the IoN as an experimental model of orofacial neuropathic pain. The euthanasia was performed at 1, 7 and 14 days postoperatively. Brain stem (medulla oblongata) samples were processed and submitted to an immunohistochemical method for detecting CD11b, a marker of microglia. The pattern of microglial activation was analyzed by optical density immunolabeling. Only the CCI group showed orofacial neuropathic pain behavior. There was no statistically difference between CTL2 and CTL1 groups in any of the experimental periods. There was a higher immunolabeling pattern showed in CCI both ipsilateral as on the contralateral side at 7 and 14 days postoperatively when...