Dietary restriction slows the abnormally rapid loss of spiral ganglion neurons in C57BL/6 mice.

Dietary restriction as a means extending the life span and exploring the aging process has interested researchers for over 50 years. We wanted to determine whether dietary restriction would alter the unusually rapid aging of the auditory ganglion in the C57BL/6NNia mouse. Quantitative methods were used to estimate the number of spiral ganglion neurons in the cochleas of 18 month-old dietary restricted and ad libitum-fed C57BL/6NNia mice. The number of spiral ganglion neurons in dietary restricted mice was significantly higher than those on an ad libitum diet. This is the first study to quantitatively demonstrate that severe neuron loss in the auditory ganglion of a mouse suffering inherited, prepubertal deafness can be slowed by caloric restriction.