Assessment of hearing in 80 inbred strains of mice by ABR threshold analyses

Abstract

The common occurrence of hearing loss in both humans and mice, and the anatomical and functional similarities of their inner ears, attest to the potential of mice being used as models to study inherited hearing loss. A large-scale, auditory screening project is being undertaken at The Jackson Laboratory (TJL) to identify mice with inherited hearing disorders. To assess hearing sensitivity, at least five mice from each inbred strain had auditory brainstem response (ABR) thresholds determined. Thus far, we have screened 80 inbred strains of mice; 60 of them exhibited homogeneous ABR threshold values not significantly different from those of the control strain CBA/CaJ. This large database establishes a reliable reference for normal hearing mouse strains. The following 16 inbred strains exhibited significantly elevated ABR thresholds before the age of 3 months: 129/J, 129/ReJ, 129/ SvJ, A/J, ALR/LtJ, ALS/LtJ, BUB/BnJ, C57BLKS/J, C57BR/cdJ, C57L/J, DBA/2J, I/LnJ, MA/MyJ, NOD/LtJ, NOR/LtJ, and SKH2/J. These hearing impaired strains may serve as models for some forms of human non-syndromic hearing loss and aid in the identification of the underlying genes.

A comparison of vestibular and auditory phenotypes in inbred mouse strains

“…In addition, available ABR data show that CE/J and SJL/J strains retain good hearing (at least up to 400 days of age) or may develop a mild hearing loss at or beyond 1 year of age (Zheng et al, 1999). The early onset gravity receptor deficit in the absence of hearing loss (including significant agerelated hearing loss) suggests that selective vestibular dysfunction may occur.…”

“…While mouse ABR data are available from a number of resources, recording methods often differ among laboratories, making it virtually impossible to group ABR data collected across laboratories. Therefore, the comparison ABR data used herein were collected by the same laboratory using the methods published by Zheng et al (1999). From the individual mouse data, we calculated means and standard deviations for the 32 kHz thresholds of age-and strain-matched mice.…”

“…Therefore, using the highest frequency data available would facilitate identification of any hearing loss regardless of the underlying etiology. The upper limit of "normal" for the 32 kHz stimulus was defined by Zheng et al (1999) as three standard deviations above the average 32 kHz threshold obtained from CBA/CaJ mice (i.e., 54 dB peSPL). We used this defined limit for the comparison made in the present study.…”

“…Three strains (SJL/J, CE/J, and MRL/MpJ) show elevated VsEP thresholds but no concomitant hearing loss. The dashed lines depict the upper limits of normative ranges for VsEPs (vertical line) and ABRs (horizontal line from Zheng et al, 1999). The lower left quadrant reflects normal VsEP and ABR thresholds, the lower right quadrant reflects abnormal VsEP with normal ABR thresholds, the upper right reflects abnormal VsEP and ABR thresholds, and the upper left reflects normal VsEP and abnormal ABR.…”

“…To do this, we compared VsEP and ABR thresholds for age-and strain-matched mice. ABR thresholds for inbred strains were obtained from data published by Zheng et al (1999), the Hereditary Hearing Impairment in Mice website (http://www.jax.org/hmr/screening.html) and the Mouse Phenome Database (http://aretha.jax.org/pub-cgi/phenome/mpdcgi?rtn=docs/home).…”