Meeting Abstract
Vertebrate animals can undergo changes in sensory physiology due to aging. Despite our increased knowledge regarding the underlying mechanisms of aging, we still have a limited understanding of how senescence (aging process) affects hearing across different vertebrate taxa. In our project, we aimed to characterize the effects of aging on the auditory sensitivity of zebrafish (Danio rerio). Zebrafish have become a valuable model system for studying the effects of aging because of their availability in large numbers, ease of manipulation, and relatively short lifespan (~40 months on average for wildtype zebrafish). In addition, research on the zebrafish auditory system may eventually provide insight into conserved molecular and genetic mechanisms of age-related hearing loss across multiple taxa. Previous observations in mammals have shown that age-related hearing loss has the most impact on encoding high frequency sounds. We test the hypothesis that zebrafish undergo age-related changes in auditory sensitivity such that the higher frequencies in the zebrafish hearing range are more greatly affected by senescence. We characterize the auditory sensitivity of three zebrafish age groups: 12-month-old, 20-month-old and 36-month-old. We used AB/WIK zebrafish from each of the age groups and applied the auditory evoked potential (AEP) recording technique for measuring the sensitivity of the zebrafish auditory periphery (i.e., the combined auditory evoked response of the inner ear, auditory nerve, and brainstem). We found that the oldest age zebrafish group (36 months of age) had the poorest auditory sensitivity across the five tested frequencies (115Hz, 800Hz, 1850Hz,3700Hz, 4500Hz). In ongoing measurements, we also aim to characterize aging-related auditory changes in adult zebrafish using a behavioral paradigm.
