Correlative studies of axonal spheroids and Lafora-like bodies in aged dogs.

The gracile nucleus and conus medullaris, the sites of predilection for spheroids and Lafora-like bodies, were examined light and electron microscopically in 91 dogs ranging from 1 month to 19 years of age. The number of both structures showed a tendency to increase with age. Spheroids have already been found in younger dogs before the appearance of Lafora-like bodies. In the aged dog, intra-spheroidal Lafora-like bodies were occasionally observed. Correlative studies may yield clues on the pathogenesis of aging phenomena in the CNS.