Age-related decline of auditory function in the chinchilla (Chinchilla laniger).
The aim of this study was to examine the functional consequences of aging in the chinchilla, a rodent with a relatively long life span and a range of hearing similar to that of humans. Subjects were 21 chinchillas aged 10-15 years, and 23 young controls. Thresholds were determined from auditory evoked potentials (EVPs), and outer hair cell (OHC) functioning was assessed by measuring 2f1-f2 distortion product otoacoustic emissions (DPOAEs). Six cochleas from 11-12-year-old animals were examined for hair cell loss and gross strial pathology. The results show that the chinchilla exhibits a small but significant decline of auditory sensitivity and OHC functioning between 3 and 15 years of age, with high-frequency losses exceeding and growing more rapidly than low-frequency losses. Compared to rodents with shorter life spans, the chinchilla has a rate of loss that is more similar to that of humans, which could make it a valuable model for understanding the etiology of human presbycusis.
McFadden
S L
SL
Center for Hearing and Deafness, Department of Communicative Disorders, SUNY at Buffalo, NY 14214, USA. mcfadden@acsu.buffalo.edu
Campo
P
P
Quaranta
N
N
Henderson
D
D
D000161:Acoustic Stimulation; D000375:Aging / Q000502:physiology*; D000818:Animals; D001309:Auditory Threshold / Q000502:physiology; D002682:Chinchilla; D003051:Cochlea / Q000473:pathology / Q000503:physiopathology; D004195:Disease Models, Animal; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D018072:Hair Cells, Auditory, Outer / Q000473:pathology / Q000502:physiology*; D009622:Noise / Q000009:adverse effects; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology; D011304:Presbycusis / Q000209:etiology / Q000503:physiopathology*; D013316:Stria Vascularis / Q000473:pathology