[Glycogenosis in cochlea of aging mice]

CBA/Caj mice and C57BL/6Nsd mice (animal models widely used for study of presbycusis) were used to study glycogen metabolic changes in the aging cochlea by a quantitative analysis of histochemistry. Glycogen contents in both hair cells and stria vascularis were significantly increased in CBA aged mice (18 and 36 months) as compared with those in CBA young animals (6 weeks), indicating a glycogenosis in the cochlea within naturally aging CBA mice. The glycogen contents in the stria vascularis in C57BL mice (6 weeks) was higher than in CBA (6 weeks) mice, whereas no significant difference could be discerned in the hair cell glycogen level. The results suggest that the glycogen metabolic changes in the CBA mice, a model of the natural aging cochlea, were different from in the C57 mice, a model of the cochlear genetic defect.