TY - JOUR
T1 - Vulnerability to noise-induced hearing loss in 'middle-aged' and young adult mice
T2 - A dose-response approach in CBA, C57BL, and BALB inbred strains
AU - Ohlemiller, Kevin K.
AU - Wright, James S.
AU - Heidbreder, Arnold F.
N1 - Funding Information:
We thank Drs. W.W. Clark, J.D. Miller, M.E. Warchol, and our reviewers for helpful comments, and J.M. Lett for technical assistance. Supported by grants from the Spencer T. and Anna W. Olin Foundation to C.I.D., and from the Edward Mallinckrodt, Jr. Foundation and NIH (R01 DC03454) to K.K.O.
PY - 2000
Y1 - 2000
N2 - Vulnerability of the cochlea to noise-induced permanent threshold shifts (NIPTS) was examined in young adult (1-2 months) and 'middle-aged' (5-7 months) CBA/CaJ, C57BL/6J, and BALB/cJ inbred mice. For each age and strain, a dose-response paradigm was applied, whereby groups of up to 12 animals were exposed to intense broadband noise (110 dB SPL) for varying durations. Exposure durations reliably associated with <10% and >90% probability of a criterion amount of NIPTS (determined 2 weeks post-exposure) were identified, and the minimum NIPTS exposure and the slope of the dose-response relation were then derived by numerical modeling. For all three strains, young adult mice were more susceptible to NIPTS than older adults; That is, a shorter exposure was able to cause NIPTS in the younger mice. Strain comparisons revealed that C57 mice were more susceptible than CBAs in the older age group only. At both ages examined, however, BALB mice were most susceptible to NIPTS. When animals with a similar amount of NIPTS were compared, outer hair cell loss in the cochlear base was more widespread in the younger animals. BALB mice appear particularly susceptible to noise-induced outer hair cell loss throughout life. Our data suggest that the mechanism or site of noise injury differs between young adults and older adults, and may depend on genetic background. The finding that both BALB and C57 mice, which show pronounced age-related hearing loss, are also especially vulnerable to noise supports the notion that genes associated with age-related hearing loss often act by rendering the cochlea susceptible to insults. Copyright (C) 2000 Elsevier Science B.V.
AB - Vulnerability of the cochlea to noise-induced permanent threshold shifts (NIPTS) was examined in young adult (1-2 months) and 'middle-aged' (5-7 months) CBA/CaJ, C57BL/6J, and BALB/cJ inbred mice. For each age and strain, a dose-response paradigm was applied, whereby groups of up to 12 animals were exposed to intense broadband noise (110 dB SPL) for varying durations. Exposure durations reliably associated with <10% and >90% probability of a criterion amount of NIPTS (determined 2 weeks post-exposure) were identified, and the minimum NIPTS exposure and the slope of the dose-response relation were then derived by numerical modeling. For all three strains, young adult mice were more susceptible to NIPTS than older adults; That is, a shorter exposure was able to cause NIPTS in the younger mice. Strain comparisons revealed that C57 mice were more susceptible than CBAs in the older age group only. At both ages examined, however, BALB mice were most susceptible to NIPTS. When animals with a similar amount of NIPTS were compared, outer hair cell loss in the cochlear base was more widespread in the younger animals. BALB mice appear particularly susceptible to noise-induced outer hair cell loss throughout life. Our data suggest that the mechanism or site of noise injury differs between young adults and older adults, and may depend on genetic background. The finding that both BALB and C57 mice, which show pronounced age-related hearing loss, are also especially vulnerable to noise supports the notion that genes associated with age-related hearing loss often act by rendering the cochlea susceptible to insults. Copyright (C) 2000 Elsevier Science B.V.
KW - Aging
KW - Ahl
KW - Ahl2
KW - Auditory brainstem response
KW - Cochlea
KW - Hair cell
KW - Mouse
KW - Presbycusis
UR - http://www.scopus.com/inward/record.url?scp=0033796186&partnerID=8YFLogxK
U2 - 10.1016/S0378-5955(00)00191-X
DO - 10.1016/S0378-5955(00)00191-X
M3 - Article
C2 - 11033262
AN - SCOPUS:0033796186
VL - 149
SP - 239
EP - 247
JO - Hearing Research
JF - Hearing Research
SN - 0378-5955
IS - 1-2
ER -