Quantifying Effects of Aging Across Structures of the Mouse Auditory System With In-Vitro Brain Slice Preparations
TLDR Chronological age affects the mouse auditory cortex more than hearing loss, and the brain may be less sensitive to mitochondrial dysfunction.
The dissertation by Kevin A. Stebbings investigated the effects of aging on the mouse auditory system and metabolism, focusing on the auditory cortex and hippocampus. The study found that chronological age, rather than hearing loss, primarily altered inhibition and rate-level functions in the auditory cortex. An unexpected increase in redox potential was observed in specific hippocampal regions of older mice, particularly those with lower body weights. The research also examined the PolG mouse model, which has increased mitochondrial DNA mutations, to test the mitochondrial theory of aging. Despite advanced aging features like hearing and weight loss, PolG mice did not show accelerated brain aging, suggesting that the brain might be less sensitive to mitochondrial dysfunction compared to other tissues. These findings highlighted the complexity of aging processes and the potential for differential aging across body tissues.