Morphine treatment during pregnancy modulates behavioral selection in lactating rats

Autor(es)

Cruz, Aline de Mello ^[1] ; Maiorka, Paulo C. ^[1] ; Canteras, Newton S. ^[2] ; Sukikara, Marcia H. ^[1] ; Felicio, Luciano F. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Fac Med Vet & Zootecnia, Dept Patol, BR-05588000 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Dept Anat, Inst Ciencias Biomed 3, BR-05508900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Physiology & Behavior; v. 101, n. 1, p. 40-44, AUG 4 2010.
• Citações Web of Science: 9

Resumo

Previous studies have demonstrated that treatment of postpartum female rats with morphine inhibits maternal behavior and stimulates foraging. Exposure to drugs of abuse may result in a progressive enhancement of their reinforcing effects. Puerperal treatment with morphine leads to reverse tolerance to this drug. The present study investigated whether repeated morphine treatment during late pregnancy may influence the effects of different morphine dosages on behavioral selection in lactating rats. Females were simultaneously exposed to pups and insects, and the choice between taking care of the pups and hunting insects was observed. Female Wistar rats were treated with morphine (3.5 mg/kg/day, subcutaneous {[}s.c.]) or saline for 5 days beginning on pregnancy day 17. On day 5 of lactation, animals were acutely challenged with morphine (0.5, 1.0, or 1.5 mg/kg, s.c.; MM0.5, MM1.0, and MM1.5 groups, respectively) or saline (MS group) and tested for predatory hunting and maternal behavior. Control groups were pretreated with saline and challenged with morphine (SM0.5, SM1.0, and SM1.5 groups) or saline (SS group). Animals treated with morphine during late pregnancy and acutely challenged with 1.0 mg/kg morphine (MM1.0 group) exhibited significantly decreased maternal behavior and enhanced hunting. This effect was not evident with the 0.5 mg/kg dose. The 1.5 mg/kg morphine dose decreased maternal behavior and increased hunting in both the MM1.5 group and in animals challenged with morphine after previous saline treatment (SM1.5 group). These results provide evidence of plasticity of the opioidergic role in behavioral selection during lactation. (C) 2010 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 07/04224-0 - Efeitos da administração de interleucina-2 no comportamento maternal e na liberação in vivo de dopamina em núcleo accumbens de ratas
• Beneficiário: Luciano Freitas Felicio
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 06/58263-3 - Investigação do papel da modulação opioidérgica e endócrina na seleção comportamental após o parto
• Beneficiário: Aline de Mello Cruz
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 03/00819-8 - Significado neuroetologico da participacao peptidergica no comportamento maternal.
• Beneficiário: Marcia Harumi Sukikara
• Modalidade de apoio: Bolsas no Brasil - Doutorado