Transport of animals between rooms: A little-noted aspect of laboratory procedure that may interfere with memory

This study investigated the effects of transporting animals from the experimental room to the animal facility in between experimental sessions, a procedure routinely employed in experimental research, on long-term social recognition memory. By using the intruder-resident paradigm, independent groups of Wistar rats exposed to a 2-h encounter with an adult intruder were transported from the experimental room to the animal facility either 0.5 or 6h after the encounter. The following day, residents were exposed to a second encounter with either the same or a different (unfamiliar) intruder. Resident`s social and non-social behaviors were carefully scored and subjected to Principal Component Analysis, thus allowing to parcel out variance and relatedness among these behaviors. Resident rats transported 6h after the first encounter exhibited reduced amount of social investigation towards familiar intruders, but an increase of social investigation when exposed to a different intruder as compared to the first encounter. These effects revealed a consistent long-lasting (24h) social recognition memory in rats. In contrast, resident rats transported 0.5 h after the first encounter did not exhibit social recognition memory. These results indicate that this common, little-noted, laboratory procedure disturbs long-term social recognition memory. (C) 2011 Elsevier B.V. All rights reserved.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES), Brazil

Brown-Coxe postodoctoral fellowship

Brown-Coxe postodoctoral fellowship

National Association of Research on Schizophrenia and Depression (NARSAD)

National Association of Research on Schizophrenia and Depression (NARSAD)

National Institutes of Health (NIH)[MH01527]

U.S. National Institutes of Health (NIH)

National Institutes of Health (NIH)[MH52711]

U.S. National Institutes of Health (NIH)

Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)