What is the impact of low testosterone levels on the anatomical and behavioral repertoire of long-term enriched housing of male mice?

Autor(es)

Lima, F. B. ^[1] ; Spinelli de Oliveira, E. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Fed Santa Catarina, Ctr Ciencias Biol, Dept Fisiol, BR-88040970 Florianopolis, SC - Brazil

^[2] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Biochem, Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Behavioural Processes; v. 108, p. 57-64, OCT 2014.
• Citações Web of Science: 3

Resumo

Environmental enrichment is a strategy to improve animal welfare, providing brain plasticity with changes at cellular, molecular and behavioral levels. In order to test the long-term effects of enriched housing and the importance of testosterone levels for the expression of behavioral plasticity, 28 categories were assessed in 45 adult Swiss mice, subdivided in prepubertal castrated and non-castrated groups, maintained for seven months as three non-sibling mates. Enrichment consisted of introducing insets for gnawing, climbing and hiding. Tests of spontaneous exploration (barrier), territoriality (intruder) and hierarchical organization (group) were applied at once. Measurements of body weight and the relative weight of key organs were done at the end of the experiment. Mice kept in enriched cages, either castrated or non-castrated, showed more spontaneous exploration than those raised in standard cages. Non-castrated mice housed in structured cages had a lower frequency of attack in the resident-intruder test than the non-castrated standard caged mice, indicating a decrease in territoriality in the first group. Independent of the housing conditions, castrated mice showed reduction of offensive, defensive, and social contacts, as well as low frequency of attack in both agonistic tests. The well-known importance of testes to ensure the expression of aggressive and social contact behaviors was therefore not challenged by the enrichment condition. Behavioral repertoire at the home cage, performance in the group-test, and organometric measurements were not significantly different between the groups kept in enriched and non-enriched cages. Our results suggest that the experience in enriched environment does not increase aggressiveness in their routine in the home-cage nor negatively influence physiological parameters, independently of the testosterone level. (C) 2014 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 97/12913-6 - Estudo comparativo da relação entre agressividade, castração e distribuição do óxido nítrico sintase no sistema nervoso de diferentes linhagens de camundongos machos
• Beneficiário: Fernanda Barbosa Lima
• Modalidade de apoio: Bolsas no Brasil - Mestrado