Physiological Evidence for Delayed Age-related Hearing Loss in Two Long-lived Rodent Species (Peromyscus leucopus and P. californicus)

AbstractDeer mice (genusPeromyscus) are an emerging model for aging studies due to their longevity relative to rodents of similar size. AlthoughPeromyscus species are well-represented in genetic, developmental, and behavioral studies, relatively few studies have investigated auditory sensitivity in this genus. Given the potential utility ofPeromyscus for investigations of age-related changes to auditory function, we recorded auditory brainstem responses (ABRs) in twoPeromyscus species,P. californicus, andP. leucopus, across the lifespan. We compared hearing sensitivity and ABR wave metrics measured in these species with measurements fromMus musculus (CBA/CaJ strain) to assess age-related effects on hearing across species. Recordings in young animals showed that all species had similar hearing ranges and thresholds with peak sensitivity ranging from 8 to 16  kHz; however,P. californicus andP. leucopus were more sensitive to frequencies below 8  kHz. AlthoughM. musculus showed significant threshold shifts across a broad range of frequencies beginning at middle age and worsening among old individuals, olderPeromyscus mice retained good sensitivity to sound across their lifespan. Middle-agedP. leucopus had comparable thresholds to young for frequencies below 24  kHz.P. leucopus also had notably large ABRs that were robust to age-related amplitude reductions, although response latencies increased with age. OldP. californicus were less sensitive to mid-range tones (8 –16 kHz)...

Source: JARO - Journal of the Association for Research in Otolaryngology - July 26, 2022 Category: ENT & OMF Source Type: research