Involution of the auditory neuro-epithelium in a tiger (Panthera tigris) and a jaguar (Panthera onca)

Numerical atrophy of the hair cells of the organ of Corti of the inner ear in a 14-year-old tiger and a 17-year-old jaguar is described. The decrease in number of sensory hair cells is considered to represent physiological atrophy caused by the process of ageing. The findings are compared with previous observations on man, guinea-pigs, shrews, and bats. The development of the physiological involution of the hearing neuro-epithelium is discussed.