Routine post-weaning handling of rats prevents isolation rearing-induced deficit in prepulse inhibition

Autor(es)

M.L.N.M. Rosa ; R.C.B. Silva ; F.T. Moura-de-Carvalho ; M.L. Brandão ; F.S. Guimarães ; E.A. Del Bel

• Tipo de documento: Artigo Científico
• Fonte: Brazilian Journal of Medical and Biological Research; v. 38, n. 11, p. 1691-1696, Nov. 2005.

Resumo

Rats reared under isolation conditions from weaning present a number of behavioral changes compared to animals reared under social conditions (group housing). These changes include deficits in prepulse inhibition (PPI) of the startle reflex to a loud sound. PPI refers to the reduction of the magnitude of the startle reflex when a relatively weak stimulus (the prepulse) precedes by an appropriate time interval the intense startle-elicing stimulus (the pulse). PPI is useful for studying sensorimotor integration. The present study evaluated the effect of handling on the impairment of PPI induced by isolation-rearing. Male Wistar rats (N = 11-15/group) were housed in groups (5 per cage and handled three times a week) or isolated (housed individually) since weaning (21 days) for 10 weeks when they reach approximately 150 g. The isolated rats were divided into "minimally handled" animals (handled once a week for cleaning purposes only) or "handled" animals (handled three times a week). This handling consisted of grasping the rat by the tail and moving it to a clean cage (approximately 5 s). A statistically significant reduction (52%) in the PPI test was found only in the isolated group with minimal handling while no difference was seen between grouped animals and isolated handled animals. These results indicate that isolation rearing causes disruption in the PPI at adult age, which serves as an index of attention deficit. This change in the sensory processing of information induced by post-weaning isolation can be prevented by handling during the development of the animal. (AU)

• Processo FAPESP: 98/10639-7 - Neurobiologia de respostas comportamentais a eventos aversivos 2
• Beneficiário: Francisco Silveira Guimaraes
• Linha de fomento: Auxílio à Pesquisa - Temático
• Processo FAPESP: 00/12108-0 - Expressão de RNA mensageiro para receptores AMPA/KA no cérebro de ratos submetidos a episódios de estresse por imobilização forçada e isolamento social
• Beneficiário: Maria Luiza Nunes Mamede Rosa
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado