Environmental impoverishment and aging alter object recognition, spatial learning, and dentate gyrus astrocytes

Environmental and age-related effects on learning and memory were analysed and compared with changes observed in astrocyte laminar distribution in the dentate gyrus. Aged (20 months) and young (6 months) adult female albino Swiss mice were housed from weaning either in impoverished conditions or in enriched conditions, and tested for episodic-like and water maze spatial memories. After these behavioral tests, brain hippocampal sections were immunolabeled for glial fibrillary acid protein to identify astrocytes. The effects of environmental enrichment on episodic-like memory were not dependent on age, and may protect water maze spatial learning and memory from declines induced by aging or impoverished environment. In the dentate gyrus, the number of astrocytes increased with both aging and enriched environment in the molecular layer, increased only with aging in the polymorphic layer, and was unchanged in the granular layer. We suggest that long-term experience-induced glial plasticity by enriched environment may represent at least part of the circuitry groundwork for improvements in behavioral performance in the aged mice brai

Nonmass enhancement on breast MRI: review of patterns with radiologic-pathologic correlation and discussion of management

OBJECTIVE: The purpose of this article is to review the varied appearances and associated diagnoses of nonmass enhancement on breast MRI with radiologic-pathologic correlation. CONCLUSION: Knowledge of the distribution and internal characteristics of these findings is helpful to determine when core needle biopsy is indicated. Correlating imaging with pathologic findings is critical in making appropriate recommendations regarding clinical management