抄録
The ultrastructural morphology of the spheroids in the gracile nucleus and cauda equina was studied in 8 autopsied dogs 7 to 16 years of age. The spheroids were shown to originate in the myelinated, unmyelinated and terminal axons and they were tentatively classified into two types based upon the internal structures: The one consisted of intreased and combined, axoplasmic organellae, such as mitochondria, neurofilaments, microtubules and smooth-surfaced endoplasmic reticulum (sER), and the other consisted mainly of sER. The former type of spheroids showed various alterations with advancing age in the interior structurre, axolemmal demarcation and occurrence of filamentous round bodies, as well as huge vacuolation and accumulation of electron-dense materials. The findings were similar to those described in axonal dystrophy of man and animals, Hallervorden-Spatz disease, infantile neuroaxonal dystrophy and experimental vitamin E-deficient rats.
