Sex-related long-term behavioral and hippocampal cellular alterations after nociceptive stimulation throughout postnatal development in rats

Autor(es)

Lima, Marcia ^[1] ; Malheiros, Jackeline ^{[1, 2]} ; Negrigo, Aline ^[1] ; Tescarollo, Fabio ^[1] ; Medeiros, Magda ^[3] ; Suchecki, Deborah ^[4] ; Tannus, Alberto ^[2] ; Guinsburg, Ruth ^[5] ; Covolan, Luciene ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo, Dept Fisiol, BR-04023062 Sao Paulo - Brazil

^[2] Univ Sao Paulo IFSC USP, Inst Fis Sao Carlos, Ctr Imagens & Espect In Vivo Ressonancia Magnet C, BR-13566590 Sao Carlos, SP - Brazil

^[3] Univ Fed Rural Rio de Janeiro, Dept Ciencias Fisiol, BR-23890000 Seropedica - Brazil

^[4] Univ Fed Sao Paulo, Dept Psicobiol, BR-04023062 Sao Paulo - Brazil

^[5] Univ Fed Sao Paulo, Dept Pediat, Disciplina Pediat Neonatal, BR-04023062 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Neuropharmacology; v. 77, p. 268-276, FEB 2014.
• Citações Web of Science: 14

Resumo

Early noxious stimuli may alter the neurogenesis rate in the dentate gyrus and the behavioral repertoire of adult rats. This study evaluated the long-term effects of noxious stimulation, imposed in different phases of development, on nociceptive and anxiety-like behaviors, hippocampal activation, cell proliferation, hippocampal BDNF and plasma corticosterone levels in 40 day-old male and female adolescents. Noxious stimulation was induced by intra-plantar injection of Complete Freund's adjuvant (CFA), on postnatal days (P) 1 (group P1), 8 (P8) or 21 (P21). Control animals were not stimulated in any way. On P21 a subset of animals from each group received BrdU and was perfused on P40 for identification of proliferating cells in the granule cell layer of the dentate gyrus. Another subset of rats was subjected to behavioral testing on P40 and one week later, to magnetic resonance imaging (MRI) acquisition. Noxious stimulation evoked hypoalgesia in adolescents, mainly in females (P < 0.02), reflected by greater latency to withdraw the paw and less paw lickings in the hot plate test than controls (P < 0.001). It also resulted in more time spent in the open arms, e.g., less anxiety-like behavior than controls (P < 0.01), especially in females (P < 0.01, compared with males). Proliferative cell rate in the dentate gyrus was the highest in P8 males and females (P < 0.001), with males exhibiting more proliferation than females on P1 and PS, which was directly related to the hippocampal levels of BDNF and inversely related to plasma corticosterone. Sex differences were also detected in manganese-enhanced MRI signal, which was more prominent in P1 females than males (P < 0.01). This study represents the first step of investigation on the cellular basis of the sex-dependent long-term consequences of nociceptive stimuli in newborns. (C) 2013 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 09/53646-0 - Efeitos da estimulacao nociceptiva inflamatoria em ratos recem-nascidos sobre a cognicao, proliferacao e diferenciacao celular no hipocampo
• Beneficiário: Luciene Covolan
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 05/56663-1 - Centro de imagens e espectroscopia in vivo por ressonância magnética para estudo de modelos animais
• Beneficiário: Alberto Tannús
• Modalidade de apoio: Auxílio à Pesquisa - Programa CINAPCE - Temático