The spiral organ of the chinchilla was studied by the surface-preparation technique in four different age groups: 1 month, 6 months, 1 year, and 4 years, to assess age-related hair cell loss. Decrease in hair cell population is linearly related to age, and damage rate of outer hair cells is greater than that of inner hair cells. The mean percentage of damaged total outer hair cells was 0.60%, 1.16%, 1.71%, and 7.07% in animals in 1 month, 6 months, 1 year, and 4 years of age, respectively. Outer hair cell loss was greatest in the apex of the cochlea and, of these cells, the outermost row was the most affected. Damage to inner hair cells also increases with age. Age-related apical cochlear cell loss in the chinchilla is comparable to that observed in other laboratory animals.
CrowleyDESchramVLSwainREMaiselRHRauchbachESwansonSN. An animal model for presbycusis. Laryngoscope1972; 82: 2079–91.
2.
CorsoJF. Presbycusis as a complicating factor in evaluating noise-induced hearing loss. In: HendersenDHamernikRPDosanjhDSMillsJH, eds. New York: Raven Press, 1976: 497–524.
3.
HenryKRCholeRA. Genotypic differences in behavioral, physiological and anatomical expressions of age-related hearing loss in the laboratory mouse. Audiology1980; 19: 369–83.
4.
HenryKRMcGinnMDCholeRA. Age-related auditory loss in the Mongolian gerbil. Arch Otorhinolaryngol1980; 228: 233–8.
5.
DumNSchmidtUVon WedelH. Age related changes in the auditory evoked brain stem potentials of albino and pigmented guinea pigs. Arch Otolaryngol1980; 228: 249–58.
6.
BredbergG. Cellular pattern and nerve supply of the human organ of Corti. Acta Otolaryngol (Stockh)1968 (suppl 236).
7.
JohnssonLGHawkinsJE. Sensory and neural degeneration with aging, as seen in microdissections of the human inner ear. Ann Otol Rhinol Laryngol1972; 81: 179–93.
8.
FederspilP. Das cochleogramm des normales Meerschweinchens. Arch Klin Exp Ohren Nasen Kehlkopfheilkunde1972; 201: 283–93.
9.
UlehlovaL. Normal cellular pattern of the organ of Corti in the guinea pig. Arch Klin Exp Ohren Nasen Kehlkopfheilkunde1973; 204: 321–30.
10.
DayalVSBarekWG. Cochlear changes from noise, kanamycin and aging. Laryngoscope1975; 85 (suppl 1) :1–18.
11.
ColemanJW. Hair cell loss as function of age in the normal cochlea of the guinea pig. Acta Otolaryngol (Stockh)1976; 82: 33–40.
12.
KeithleyEMFeldmanML. Hair cell counts in an age-graded series of rat cochleas. Hear Res1982; 8: 249–62.
13.
MillerJD. Audibility curve of the chinchilla. J Acoust Soc Am1970; 48: 513–23.
14.
StockwellCWAdesHWEngstromH. Patterns of hair cell damage after intense auditory stimulation. Ann Otol Rhinol Laryngol1969; 78: 1144–68.
15.
BohneBA. Safe level for noise exposure?. Ann Otol Rhinol Laryngol1976; 85: 1–14.
16.
SantiPAMulchowDC. Morphometry of the chinchilla organ of Corti and stria vascularis. J Histochem Cytochem1979; 27: 1539–42.
17.
BrowningGGNorthropRCorteseR. Selective destruction of the outer hair cells in the chinchilla. Clin Otolaryngol1982; 7: 3–9.
18.
CampbellRC. Statistics for biologists. London: Cambridge University Press, 1974: 177–85.
19.
EhretG. Correlations between cochlear hair cell loss and shifts of marked and absolute behavioral auditory thresholds in the house mouse. Acta Otolaryngol (Stockh)1979; 87: 28–38.
20.
Hunter-DuvarIMSuzukiMMountRJ. Anatomical changes in the organ of Corti after acoustic stimulations. In: HamernikRPHendersonDSalviR, eds. New perspectives on noise-induced hearing loss. New York: Raven Press, 1982: 3–22.
21.
LimDJDunnDEFerraroJALempertBL. Anatomical changes found in the cochleas of animals exposed to typical industrial noise. In: HamernikRPHendersonDSalviR, eds. New perspectives on noise-induced hearing loss. New York: Raven Press, 1982: 23–48.
22.
CovellWPRogersJB. Pathological changes in the inner ears of senile guinea pigs. Laryngoscope1957; 67: 118–29.
23.
SchuknechtHF. Further observations on the pathology of presbycusis. Arch Otolaryngol1964; 80: 369–82.
24.
BernsteinJMSilversteinH. Anterior cerebellar and labyrinthine arteries. Arch Otolaryngol1966; 83: 422–35.
25.
KimuraRS. Cochlear vascular lesions. In: de LorenzoDarin AJ, ed. Vascular disorders and hearing defects. Baltimore: University Park Press, 1973: 205–18.
26.
AxelssonA. The cochlear blood vessels in guinea pigs of different ages. Acta Otolaryngol (Stockh)1971; 72: 172–81.
27.
AxelssonALipscombeD. The vascular pattern of the chinchilla cochlea. Acta Otolaryngol (Stockh)1975; 79: 352–65.
28.
JohnssonLGHawkinsJE. Vascular changes in the human inner ear associated with aging. Ann Otol Rhinol Laryngol1972; 81: 364–76.
29.
JohnssonLG. Cochlear blood vessel pattern in the human fetus and postnatal vascular involution. Ann Otol Rhinol Laryngol1972; 81: 22–40.
30.
MakishimaK. Arteriolar sclerosis as a cause of presbycusis. Otolaryngology1978; 86: 322–6.
31.
ClarkWWBohneBA. Animal model for the 4-kHz tonal dip. Ann Otol Rhinol Laryngol1978; 87: 1–16.
