Efeitos da programação por nicotina durante a lactação nos níveis de comportamentos associados à ansiedade, busca por novos estímulos e aprendizagem/memória em ratos Wistar adolescentes e adultos

• Ano de defesa: 2011
• Autor(a) principal: Claudio Neto, Sylvio
• Orientador(a): Manhães, Alex Christian
• Banca de defesa: Carvalho, Anderson Ribeiro , Marques, Mabel Carneiro Fraga , Villaça, Yael de Abreu
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade do Estado do Rio de Janeiro
• Programa de Pós-Graduação: Programa de Pós-Graduação em Fisiopatologia Clínica e Experimental
• Departamento: Centro Biomédico::Faculdade de Ciências Médicas
• País: BR
• Palavras-chave em Português: Nicotina; Desenvolvimento; Lactação; Comportamento; Ansiedade; Comportamento do lactente; Exposição materna
• Palavras-chave em Inglês: Nicotine; Development; Lactation; Behavior; Anxiety; Infant behavior; Maternal exposure
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::FISIOLOGIA::FISIOLOGIA DE ORGAOS E SISTEMAS::NEUROFISIOLOGIA
• Link de acesso: http://www.bdtd.uerj.br/handle/1/12743

Maternal nicotine exposure during lactation in rats rogrammes for hyperleptinemia and hypothyroidism in the adult offspring. Changes in the levels of these hormones are known to affect behavior. Hence, here we investigated the short- and long-term behavioral effects of neonatal nicotine exposure in Wistar rats. Lactating rats implanted with minipumps either containing nicotine (NIC=6mg/Kg/day) or a solution with equivalent concentration of saline (C) during the second postnatal day to the nineteenth postnatal (PN) days. Sixty two NIC and 48 C rats were tested according to the following protocol: 1) Either at PN30 or PN75, anxiety levels were assessed in elevated plus-maze (EPM). Entries into each area of the maze (open and closed arms and centre square) were recorded over a period of 10 min; 2) One hour, animals were tested in the hole board arena (HB) in order to assess novelty-seeking behavior. Animals were allowed 10 min to explore. The number of explored holes was noted; 3) Either at PN31 or PN76, learning/memory was assessed in the radial arm water maze (RAWM). Each animal was tested 4 times a day for 5 consecutive days. On the 5th day, the platform was moved to the arm located in the opposite side. They were allowed 2 min to find the hidden escape platform. The latency to find the platform was noted. The percentage of time spent in the open arms of the EPM by PN30 NIC animals (6.4±1.1 %) was significantly (ANOVA: P=0.024) lower than that of PN30 C ones (9.9±1.4 %). The percentage of entries into the open arms was also significantly lower (ANOVA: P<0.04) for PN30 NIC (32.4±2.9 %) animals when compared to that of PN30 C ones (38.5±1.8 %). No differences regarding these variables were observed between PN75 groups (ANOVA: P>0.1). No differences (ANOVA: P>0.1) were observed between groups regarding the number of closed arm entries at both ages. As for the HB test, no differences were observed between groups at both ages (ANOVA: P>0.1). In the RAWM, PN75 NIC animals (274±24 s) displayed a significantly (ANOVA: P<0.006) reduced total (all trials summed) latency to find the platform when compared to PN75 C ones in the first four days (410±45 s). No difference was observed regarding PN30 animals (ANOVA: P>0.1). Neonatal nicotine programming results in a short term effect on anxiety-like behavior, observed by a high anxiety levels during adolescence. No difference was observed regarding novelty-seeking behavior. However, neonatal nicotine programming causes a long-term late emerging effect on cognitive-behavior, observed by a better performance in learning\memory task at adulthood.