[Age-related changes in the dendrites in the cat cerebral cortex (an electron microscopic study)]

Various zones of the acoustic cortex (A1, A3, A4, Ep after Voolsey) have been serially studied in two cats 12-14 years of age at electron microscopic level. Various forms of age changes have been revealed in their dendrites. The most often occurring form of the changes is the dendrites with lipofuscin granules in them. The dendrites with neuroplasm filled with numerous, sometimes aggregating electron opaque formations of various size and contour make the second form. Appearance of separate electron opaque round myelin-like bodies scattered in the dendritic neuroplasm precede the appearance of the third form. There is a various degree of disturbances in the interneuronal contacts. They depend on age alterations in the dendrites which are the most widespread postsynaptic components in the cerebral cortex. The importance to perform age selection of animals for an experimental morphological interneuronal connection investigations is stressed.