085 | Environmental enrichment rescues pattern separation deficit in a rat transgenic model of Alzheimer’s-like brain amyloidosis

Cognition, Behavior, and Memory

Author: Karen Soledad Campuzano | Email: kcampuzano@leloir.org.ar

Karen Campuzano , Sonia Do Carmo , Dinka Piromalli Girado , Pedro Bekinschtein , Eduardo Castaño , Luis Javier Santín , A. Claudio Cuello , Laura Morelli , Pablo Galeano

1° Brain Aging and Neurodegeneration Laboratory, Fundación Instituto Leloir (IIBBA-CONICET), Buenos Aires, Argentina
2° Department of Pharmacology & Therapeutics, McGill University, Montreal, Canada
3° Laboratory of Memory and Molecular Cognition, Instituto de Neurociencia Cognitiva y Traslacional (CONICET, Fundación INECO, Universidad Favaloro), Buenos Aires, Argentina
4° Department of Psychobiology and Methodology of the Behavioral Sciences, University of Malaga, and Institute for Biomedical Research of Malaga (IBIMA), Malaga, Spain

Adult hipocampal neurogenesis (AHN) is impaired in animal models of Alzheimer’s disease (AD) and in post-mortem AD brains. AHN promotes pattern separation (PS), a cognitive process by which similar stimuli are discriminated in hippocampus-dependent tasks. Moreover, PS is affected in individual with high genetic risk for AD and in patients diagnosed with AD. Here, we evaluated if the exposure to an enriched environment (EE) was able to rescue PS deficit in the McGill-R-Thy1-APP transgenic (Tg) rat model of AD, in which deficits in AHN have been previously described. To this end, 6-month-old Tg and wild-type (WT) rats were assigned to EE, or continued living in standard cages, until 9-month-old, when they were submitted to the spontaneous location recognition (SLR) task to assess PS. Using two configurations of the SLR task, the similarity of the to-be-remembered locations were parametrically manipulated by altering the spatial positions of objects-dissimilar or -similar to vary the load on pattern separation. Results showed that in the objects-dissimilar configuration all groups were able to solve the task. In contrast, in the objects-similar configuration Tg rats not exposed to EE were unable to solve the task while Tg rats exposed to EE did. These results provide evidence of a specific cognitive deficit in this Tg rat model that has not been previously studied and that is sensitive to environmental stimulation.