[Skip to Navigation]
November 1996

Age-Related Differences in Cochlear Microcirculation and Auditory Brain Stem Response

Author Affiliations

From the Department of Otolaryngology–Head and Neck Surgery, Henry Ford Hospital, West Bloomfield, Mich (Drs Seidman and Khan); Kresge Hearing Research Institute, University of Michigan, Ann Arbor (Dr Dolan); and Department of Otolaryngology–Head and Neck Surgery, Wayne State University, Detroit, Mich (Dr Quirk).

Arch Otolaryngol Head Neck Surg. 1996;122(11):1221-1226. doi:10.1001/archotol.1996.01890230067013

Objective:  To examine possible age-related differences in auditory sensitivity and cochlear vascular properties.

Design:  This study is designed to provide information regarding cochlear function using physiological and audiological measures. Each animal underwent intravital microscopic evaluation of red blood cell velocity, vessel diameter, and vascular permeability in the second turn of the cochlear lateral wall. Auditory brain stem responses were used to determine hearing sensitivity.

Subjects:  Four age ranges of male Fischer rats were studied: young, 2 to 4 months (n=9); mid-young, 9 to 11 months (n=8); mid-old, 18 to 20 months (n=6); and old, 30 to 34 months (n=10).

Results:  Auditory brain stem response testing showed an age-related decrease in auditory sensitivity. Intravital microscopic analysis showed age-related statistically significant decreases in red blood cell velocity and increased vascular permeability with a trend for reduced capillary diameters.

Conclusions:  The process of aging is associated with many biochemical and physiological changes that include decrease in cellular water concentration, ionic changes, and decreased elasticity of cellular membranes. One contributing factor to this process may be altered vascular characteristics, such as reduced flow and vascular plasticity, as well as increased vascular permeability. These age-related changes may result in reductions in oxygen and nutrient delivery, and also waste elimination. Our results suggest that progressive age-associated vascular compromise may be a contributing factor in presbycusis.Arch Otolaryngol Head Neck Surg. 1996;122:1221-1226

Add or change institution