Survey on spontaneous peripheral neuropathy in aging rats

The incidence of peripheral neuropathy in rats (Charles River bred, caesarean derived, Sprague-Dawley origin) obtained from long term studies over a 10 year period is reported. The survey included peripheral nerve samples from 14,237 males and 13,668 females. The incidence of peripheral neuropathy is 23% in untreated males and 18% in untreated females at 80-104 weeks of age. The total incidence in all rats in the survey was somewhat higher in males than females. The light and electron microscopic features of age-related peripheral neuropathy in rats is described. The peripheral neuropathy was spontaneous in origin and was age-related.