Avaliação in vivo da atividade celular por meio de imagens por ressonância magnética contrastadas por manganês (memri) após estimulação nociceptiva inflamatória em ratos recém-nascidos

• Ano de defesa: 2015
• Autor(a) principal: Malheiros, Jackeline Moraes [UNIFESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: Magnetic resonance imaging; Nociception; Central nervous system; Manganese chloride; Imagens por ressonância magnética; Sistema nervoso central; Cloreto de manganês; Nocicepção
• Link de acesso: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=2858811; http://repositorio.unifesp.br/handle/11600/47220

Neonatal noxious stimulation in rats has been proposed to model neonatal procedural pain performed in neonatal intensive care units. Previous studies have shown that the rate of hippocampal neurogenesis as well as the behavioral repertoire of adult rats may be altered in response to neonatal noxious stimuli. Several studies have used MEMRI (Manganese-enhanced MRI) approach, since the Mn2+ can act as a marker of calcium influx into cells serving as a surrogate indicator of activated areas after stimulation. The purpose of this study is to map, in adult animals, MEMRI signal alterations in brain areas related to pain after neonatal noxious stimulation. For pain induction, male and female rats received an intraplantar injection of CFA (complete Freund's adjuvant) in P1 (first postnatal day), P8 or P21. To assess whether nociceptive re-exposure could activate differentially the same brain areas, a subgroup of animals were also stimulated in the infancy (P1P21 and P8P21). Results indicate that the re-stimulated females showed higher signal intensity mainly in areas related to emotional pain control (insular cortex), recognition, learning (secondary somatosensory cortex) and pain memory (dorsal hippocampus). The P1 female group showed the same signal intensity as Naïve group in areas related to pain localization (ventrolateral thalamus and primary somatosensory cortex) and showed no signal intensity alterations in the amygdala. In the dorsal hippocampal dentate gyrus, P1 females (1.551 ± 0.053 a.u.) showed higher signal intensity than P1 males (1.203 ± 0.119 a.u., p<0.05). This area is recently related to associative memory. These results show that MEMRI can be used in animal models to map central nervous system areas related to processing long-term nociceptive information.