Development of an organotypic brain slice culture model using tissues collected from geriatric mice

Ex vivo organ slice cultures are attractive models to address specific biomedical research questions because they retain complex and dynamic three dimensional architecture. In addition, they require only a few animals as tissue donors thus greatly decreasing the number needed for live animal studies. The model has been most successful using tissues from very young mice, but has generally not been considered for aging research because of the challenge of maintaining viability of tissues collected from older mice. The brain is a high impact organ in aging and age-related disease research, so it was of interest to investigate the viability and related molecular and cellular characteristics of brain slice cultures (BSCs) derived from old mice. Coronal sections of 200 μm thickness were collected from the middle third of the brain of 21 month old C57BL/6JN mice, cultured in a standard media concoction for seven days, exposed to chemical stressors glucose, hydrogen peroxide, lipopolysaccharide, or sodium hypochlorite for 24 to 48 hours, and then rinsed and cultured for another seven days. Results in non-treated BSCs showed cellular viability of greater than 80 percent with specific aging pathways relatively unaffected. Chemical stressors selectively targeted pathways of aging including DNA damage, autophagy, and inflammation. These preliminary observations suggest that BSCs derived from geriatric mice have potential for research into brain aging and age-related neurodegenerative conditions, and could serve as a prototype for developing organ slice cultures for other organs collected from old mice.