Biomaterial Database

Distortion product otoacoustic emissions in the C57BL/6J mouse model of age-related hearing loss. 1997

K Parham

Department of Surgery, The School of Medicine, University of Connecticut Health Center, Farmington 06030-1110, USA. parham@neuron.uchc.edu

One of the earliest histopathological changes associated with age-related hearing loss appears to be the disruption of outer hair cells (OHCs). To evaluate age-related changes in OHC function, distortion product otoacoustic emissions (DPOAEs) were recorded in the young and aging C57BL/6J mouse. Starting in young adulthood, the C57 mouse displays age-related elevation of auditory brainstem response thresholds, beginning in the high frequencies and progressing toward lower frequencies. The 2f1-f2 DPOAEs of mice between 2 and 20 months of age were examined for f2s between 8 and 16 kHz. In this octave region, the features of 2f1-f2 DPOAEs in the 2-month-old C57 mouse were comparable to those described for non-murine rodents in the literature in terms of optimum f2/f1 ratio, optimum primary level difference, input/output (I/O) function features and microstructure. It was determined that f2/f1 = 1.2 and L1-L2 = 20 dB were optimal stimulus parameters for investigation of the effects of age on C57 DPOAEs. Age-related changes in DPOAE I/O functions consisted of a right shift (i.e. increased DPOAE detection thresholds), disappearance of 'notches' and shallowing of the slopes after 8 months of age. As DPOAE I/O functions continued to shift to the right and DPOAE levels decreased with age, the appearance of I/O functions became complex to include regions of steep or shallow slopes and plateaus. The present results suggest that the age-related elevation of auditory thresholds in the C57 mice is associated with substantial progressive changes in OHC function.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008810	Mice, Inbred C57BL	One of the first INBRED MOUSE STRAINS to be sequenced. This strain is commonly used as genetic background for transgenic mouse models. Refractory to many tumors, this strain is also preferred model for studying role of genetic variations in development of diseases.	Mice, C57BL,Mouse, C57BL,Mouse, Inbred C57BL,C57BL Mice,C57BL Mice, Inbred,C57BL Mouse,C57BL Mouse, Inbred,Inbred C57BL Mice,Inbred C57BL Mouse
D011304	Presbycusis	Gradual bilateral hearing loss associated with aging that is due to progressive degeneration of cochlear structures and central auditory pathways. Hearing loss usually begins with the high frequencies then progresses to sounds of middle and low frequencies.	Presbycuses
D003051	Cochlea	The part of the inner ear (LABYRINTH) that is concerned with hearing. It forms the anterior part of the labyrinth, as a snail-like structure that is situated almost horizontally anterior to the VESTIBULAR LABYRINTH.	Cochleas
D004195	Disease Models, Animal	Naturally-occurring or experimentally-induced animal diseases with pathological processes analogous to human diseases.	Animal Disease Model,Animal Disease Models,Disease Model, Animal
D000161	Acoustic Stimulation	Use of sound to elicit a response in the nervous system.	Auditory Stimulation,Stimulation, Acoustic,Stimulation, Auditory
D000375	Aging	The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.	Senescence,Aging, Biological,Biological Aging
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001309	Auditory Threshold	The audibility limit of discriminating sound intensity and pitch.	Auditory Thresholds,Threshold, Auditory,Thresholds, Auditory
D016057	Evoked Potentials, Auditory, Brain Stem	Electrical waves in the CEREBRAL CORTEX generated by BRAIN STEM structures in response to auditory click stimuli. These are found to be abnormal in many patients with CEREBELLOPONTINE ANGLE lesions, MULTIPLE SCLEROSIS, or other DEMYELINATING DISEASES.	Acoustic Evoked Brain Stem Potentials,Auditory Brain Stem Evoked Responses,Brain Stem Auditory Evoked Potentials,Evoked Responses, Auditory, Brain Stem,Acoustic Evoked Brain Stem Potential,Acoustic Evoked Brainstem Potential,Acoustic Evoked Brainstem Potentials,Auditory Brain Stem Evoked Response,Auditory Brain Stem Response,Auditory Brain Stem Responses,Auditory Brainstem Evoked Response,Auditory Brainstem Evoked Responses,Auditory Brainstem Responses,Brain Stem Auditory Evoked Potential,Brainstem Auditory Evoked Potential,Brainstem Auditory Evoked Potentials,Evoked Potential, Auditory, Brainstem,Evoked Potentials, Auditory, Brainstem,Evoked Response, Auditory, Brain Stem,Evoked Response, Auditory, Brainstem,Evoked Responses, Auditory, Brainstem,Auditory Brainstem Response,Brainstem Response, Auditory,Brainstem Responses, Auditory,Response, Auditory Brainstem,Responses, Auditory Brainstem