Table 3.
Effects of environmental enrichment on glial cells.
| Study’s primary objective | Animal species/strain | EE methods | Frequency of changing EE method | Proteins/behavior investigated | Significant findings | Reference |
|---|---|---|---|---|---|---|
| • Modulation of glial cells with EE in an animal model of AD | • PDAPP-J20 crossed with C57BL/6J mice | • Large cages with toys, extra nesting material, small plastic houses, and tubes. No running wheel | • Every 2 days | • Aβ peptides | • ↓ Astrocytes association with Aβ plaques | Beauquis et al. (2013) |
| • Amyloid plaques | • ↓ Aβ peptides | |||||
| • GFAP+ glial cells | ||||||
| • Effect of EE on glial cells within the hippocampus | • Adult male Sprague-Dawley rats | • A running wheel, a PVC tube, various small objects, and toys | • EE for 12 h each day in a separate cage | • Expression of various cytokines, chemokines, GFAP, and IBA1 | • ↑ Astrocytes and microglia antigens expression in the hippocampus but not in CA1, CA3, and cortex | Williamson et al. (2012) |
| • Expression of growth factors, BDNF and GDNF in the hippocampus. | • ↓ Expression of TNF, IL-1β, and chemokines Cc12, Cc13, and Cxc12 in the hippocampus | |||||
| • ↑ Hippocampal BDNF mRNA | ||||||
| • Effect of EE on the short-term memory for event durations and on the astrocytes percentage in hippocampus, frontal cortex, and corpus callosum | • Naive male Wistar derived rats 5 and 21 months of age | • Three large wire mesh cages interconnected with two tunnels, wooden and metallic objects, toys and balls, ladders, footbridges, and papers | • Daily | • Delayed symbolic matching to sample task test | • Behavioral testing resulted in ↑ in the astrocytes number and size and GFAP % in the hippocampus and corpus callosum of young rats | Soffié et al. (1999) |
| • Estimation of astrocytes by evaluating GFAP percentage | • Conversely, Behavioral testing resulted in ↓ in the astrocytes number and size and GFAP % in the hippocampus and corpus callosum of old rats | |||||
| • ↓ Astrocytes number and size in the hippocampus and corpus callosum of old enriched rats | ||||||
| • Reduction in memory deficit with age in old enriched rats but no total reversal of age-related impairment |
EE, environmental enrichment; AD, Alzheimer’s disease; Aβ, amyloid-β; GFAP, glial fibrillary acidic protein; PVC, polyvinyl chloride; IBA1, ionized calcium-binding adapter molecule 1; BDNF, brain-derived neurotrophic factor; GDNF, glial cell-derived neurotrophic factor; CA, Cornu Ammonis; Cc12, (C–C motif) ligand 12; Cc13, (C–C motif) ligand 13; Cxc12, (C–X–C motif) ligand 12; mRNA, messenger ribonucleic acid.