Repeated exposure of naive and peripheral nerve-injured mice to a snake as an experimental model of post-traumatic stress disorder and its co-morbidity with neuropathic pain

Autor(es)

Paschoalin-Maurin, Tatiana ^{[1, 2, 3]}

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Ribeirao Preto Med Sch, Ophidiarium LNN FMRP USP INeC, Av Bandeirantes 3900, BR-14049900 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo FMRP USP, Dept Pharmacol, Lab Neuroanat & Neuropsychobiol, Ribeirao Preto Med Sch, Av Bandeirantes 3900, BR-14049900 Ribeirao Preto, SP - Brazil

^[3] Behav Neurosci Inst INeC, Ave Cafe 2450, BR-14050220 Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Brain Research; v. 1744, OCT 1 2020.
• Citações Web of Science: 0

Resumo

Confrontation of rodents by natural predators provides a number of advantages as a model for traumatic or stressful experience. Using this approach, one of the aims of this study was to investigate a model for the study of post-traumatic stress disorder (PTSD)-related behaviour in mice. Moreover, because PTSD can facilitate the establishment of chronic pain (CP), and in the same way, patients with CP have an increased tendency to develop PTSD when exposed to a traumatic event, our second aim was to analyse whether this comorbidity can be verified in the new paradigm. C57BL/6 male mice underwent chronic constriction injury of the sciatic nerve (CCI), a model of neuropathic CP, or not (sham groups) and were submitted to different threatening situations. Threatened mice exhibited enhanced defensive behaviours, as well as significantly enhanced risk assessment and escape behaviours during context reexposure. Previous snake exposure reduced open-arm time in the elevated plus-maze test, suggesting an increase in anxiety levels. Sham mice showed fear-induced antinociception immediately after a second exposure to the snake, but 1 week later, they exhibited allodynia, suggesting that multiple exposures to the snake led to increased nociceptive responses. Moreover, after reexposure to the aversive environment, allodynia was maintained. CCI alone produced intense allodynia, which was unaltered by exposure to either the snake stimuli or reexposure to the experimental context. Together, these results specifically parallel the behavioural symptoms of PTSD, suggesting that the snake/exuvia/reexposure procedure may constitute a useful animal model to study PTSD. (AU)

• Processo FAPESP: 17/11855-8 - Estudo da influência de endocanabinoides do corpo estriado e do mesencéfalo ventral na atividade das projeções GABAérgicas neoestriado-nigro-tectais durante as reações de pânico de roedores ameaçados por serpentes peçonhentas
• Beneficiário: Norberto Cysne Coimbra
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 07/01174-1 - Estudo do envolvimento do sistema opióide, serotoninérgico e noradrenérgico do sistema endógeno de inibição de dor em processos antinociceptivos induzidos por reações de fuga orientada evocada pela estimulação química do hipotálamo medial
• Beneficiário: Norberto Cysne Coimbra
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/13398-2 - Investigação da comorbidade entre dor neuropática crônica e estresse pós-traumático: papel dos sistemas glutamatérgico, canabinoide e vaniloide envolvendo o córtex pré-límbico e a substância cinzenta periaquedutal
• Beneficiário: Joyce Mendes Gomes Tessari
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 12/03798-0 - Envolvimento de receptores opióides e endocanabinóides da substância negra na modulação da atividade da via GABAérgica nigro-tectal durante a organização do comportamento de defesa eliciado por roedores confrontados com serpentes veneníferas
• Beneficiário: Norberto Cysne Coimbra
• Modalidade de apoio: Auxílio à Pesquisa - Regular