Research ReportAuditory brainstem responses in 10 inbred strains of mice
Introduction
The auditory brainstem response (ABR) is an evoked potential measurement of auditory activity in the auditory nerve and subsequent fiber tracts and nuclei within the auditory brainstem pathways. The threshold, amplitude, and latency analysis of the ABR provides information on the peripheral hearing status and the integrity of brainstem pathways. Therefore, the measurement of ABR has become a useful and practical procedure for the determination of hearing levels in animals and young children (Arnold, 2000, Musiek et al., 1994, Parham et al., 2001). In mice, the ABR threshold has been used successfully to estimate audiometric thresholds in hearing and genetic research (Davis et al., 2002, Duan and Canlon, 1996, Erway et al., 1996, Erway et al., 1993, Hirose and Liberman, 2003, Money et al., 1995, Munemoto et al., 1998, Rosowski et al., 2003, Szymko-Bennett et al., 2003). A PubMed search using key words of mouse, ABR, and threshold has revealed 80 of these studies since 1985.
The successful use of ABR threshold for assessment of the hearing sensitivity of mice has lead to strain characterization (Zheng et al., 1999), gene localization (Galambos and Hecox, 1978, Henry, 2004, Hirose and Liberman, 2003, Huang and Buchwald, 1978, Hunter and Willott, 1987, Ikeda et al., 2002, Ingham et al., 1998, Jimenez et al., 1999, Johnson et al., 2001), and gene identification (Ikeda et al., 2002, Johnson et al., 2000, Johnson et al., 2001, Johnson et al., 2003) since 1997. Moreover, the measurement of ABR threshold has proven essential in identifying modifier genes (Ikeda et al., 2002, Johnson and Zheng, 2002, Johnson et al., 2000, Johnson et al., 2001, Noben-Trauth et al., 1997, Noben-Trauth et al., 2003, Zheng and Johnson, 2001). However, previous studies have shown that, while some hearing impairments were characterized by significant changes in all ABR parameters such as the threshold, amplitude, and latency, others were associated with the abnormalities in the amplitude and latency but not the threshold (Evans et al., 1983, Fujiyoshi et al., 1994, Kanzaki et al., 1985). For example, Kanzaki et al. (1985) have shown that the peak latency of later ABR waves for the shiverer mice was prolonged with increased inter-peak latency although the threshold was normal. To further assess the hearing sensitivity with ABR, we have studied the ABR threshold as well as the variation in amplitude and latency of ABR components as a function of stimulus intensity in 10 different inbred strains of mice. These mouse strains include BALB/cJ, C3HeB/FeJ, C3H/HeJ, CAST/EiJ, CBA/CaJ, CBA/J, FVB/NJ, MRL/MpJ, NZB/BlNJ, and SJL/J. Because these strains are commonly used and readily available, they have become increasingly important for medical research since the gene mutations on these strain backgrounds provide models for a variety of human disorders. To our knowledge, the amplitude and latency of ABR components determined at different intensities have only been reported for CBA/CaJ and CBA/J mice among these strains (Burkard et al., 2001, Hunter and Willott, 1987).
Millions of mice are produced annually at the Jackson Laboratory. These mice belong to nearly 2800 strains of genetically defined and modified strains, including standard inbred strains, recombinant inbred strains, congenic inbred strains, and inbred strains carrying both spontaneous and induced mutations. The Neuroscience Mutagenesis Facility at the Jackson Laboratory has undertaken a large scale auditory screening project, which is specifically designed to provide novel murine genetic models for human deafness. The data reported in this study provide a reliable reference for evaluating mouse hearing in terms of amplitude and latency of ABR components. The strain differences in ABR parameters reported in this study suggest genetic determinants, which may lead to gene identification and novel mechanism discovery for the future studies.
Section snippets
Results
As described above, we used clicks and tone bursts to study the ABR threshold as well as the variation in amplitude and latency of ABR components as a function of stimulus intensity in 10 different inbred strains of mice. Because of the large amount of data, we mainly present ABR results obtained using click stimulation in this report. To address the issue of age-related hearing loss (AHL), which is characterized by a gradual decrease in sensitivity in the high to low frequency direction,
Discussion
As reported in previous studies (Chuu et al., 2001, Fujiyoshi et al., 1994, Hunter and Willott, 1987, Parham et al., 2001, Zheng et al., 1999), the ABR patterns of mice typically consisted of five vertical positive waves (Figs. 1A-1, B-1). Although the precise origins of ABR waves are not yet well defined, it is generally agreed that, in animal models such as cats, ferrets, non-human primates, and rodents, the first wave represents activities from the auditory nerve while the later waves
Animals
A total of 149 mice from 10 different inbred strains were used in this study. The strain names, age, and the number of mice tested in each strain are shown in Table 1. These mice were produced within the production facilities of the Jackson Laboratory. Prior to ABR recording, animals were anesthetized by intraperitoneal injection with Avertin (tribromoethanol stabilized in tertiary amyl hydrate) given at a dose of 5 mg tribromoethanol/10 g body weight. An otoscopic examination was then
Acknowledgments
The work was supported by grants MH067670, NSFC30440080, DC005846, and a grant from the Research Board of University of Missouri-Columbia (URB-03-057). We thank Melissa L Berry for critical review of the manuscript. We thank Dr. Weidong Zhang for statistical assistance.
References (52)
- et al.
Age-related changes in auditory brainstem responses in Fischer 344 rats: effects of rate and intensity
Hear. Res.
(1994) - et al.
Brain-stem auditory evoked potentials in the rat: effects of gender, stimulus characteristics and ethanol sedation
Electroencephalogr. Clin. Neurophysiol.
(1984) - et al.
Abnormal auditory brainstem responses for mice treated with mercurial compounds: involvement of excessive nitric oxide
Toxicology
(2001) - et al.
Susceptibility to the ototoxic properties of toluene is species specific
Hear. Res.
(2002) - et al.
Genetics of age-related hearing loss in mice: I. Inbred and F1 hybrid strains
Hear. Res.
(1993) - et al.
Genetics of age-related hearing loss in mice: III. Susceptibility of inbred and F1 hybrid strains to noise-induced hearing loss
Hear. Res.
(1996) - et al.
Auditory brainstem responses in neonatally sound deprived CBA/J mice
Hear. Res.
(1983) - et al.
Comparison of cat and human brain-stem auditory evoked potentials
Electroencephalogr. Clin. Neurophysiol.
(1987) Males lose hearing earlier in mouse models of late-onset age-related hearing loss; females lose hearing earlier in mouse models of early-onset hearing loss
Hear. Res.
(2004)- et al.
Factors that affect the amplitudes and latencies of the vertex short latency acoustic responses in the cat
Electroencephalogr. Clin. Neurophysiol.
(1978)