Effects of environmental enrichment on hippocampal astroglial populations in APP transgenic mice

BEAUQUIS J; PAVÍA P; ROIG P; GALVÁN V; DE NICOLA AF; SARAVIA F

Huerta Grande, Córdoba

Congreso; XXVI Congreso anual de la Sociedad Argentina de Investigación en Neurociencias (SAN); 2011

Sociedad Argentina de Neurociencias (SAN)

Environmental stimulation plays a protecting role in the pathogenesis of Alzheimer´s disease (AD). Our aim was to explore the effect of environmental enrichment (EE) in a model of AD, focusing on astroglial changes in the hippocampus. Transgenic mice (Tg, PDAPP-J20; Swe and Ind APP mutations) and non-transgenic siblings (NTg) were housed in EE or in standard conditions (SC) for 3 months (5 to 8 months of life). Using immunohistochemistry we found a decreased density of GFAP+ astrocytes in the CA1 field in TgSC and an increase in TgEE. The volume of astrocytes was measured using confocal microscopy in 2 subpopulations: amyloid plaque-associated (PA) and non-plaque-associated (NPA) astrocytes. PA astrocytes were larger than control astrocytes, suggesting an increased reactivity, with no effect of EE. NPA astrocytes of Tg had a decreased volume when compared with those from NTg, possibly indicating astroglial atrophy. Interestingly, EE was able to increase the volume to control levels. Sholl analysis showed that astrocyte ramification was increased in TgSC (NPA and PA) but not in TgEE compared with controls. Our results indicate that EE influences astrocyte morphology in APP Tg mice, suggesting a role in the evolution of AD, modulating not only neuronal but also glial populations.