[Special forms of ultrastructural changes in dendrites and axons in the human and cat brain]

The investigation has been performed in the human brain of persons at the age of 75-87 years, in the auditory cortex of old cats and in bioplates obtained from epileptic foci of the hippocamp and the temporal cortex of 11 patients suffering from temporal epilepsy (at the age of 12-29 years). Distal parts of the dendrites contain a large amount of myelin-like membranous and electron opaque inclusions. In most cases these dendrites have no axodendritic contacts. In large trunks of the dendrites there are noted a comparatively large number of neurotubules with definitely seen contours against the background of small conglomerates of loose fine fibrillar material. Myelin axons contain a large amount of sharply contoured neurotubules which fill axoplasm. Similar dendrites and axons are revealed in the cerebral cortex both at age changes and in tissue of the epilepsy foci. These changes are supposed to result from the effect of the same factor.