[Structural disruption of the myelin sheaths in the CNS of adult rats with hereditary catatonia].

Ultrastructural studies have been made on the medio-dorsal region of n. caudatus and ventromedial part of the corpus callosum in rats with hereditary catatonia. In most of the nervous fibres, structural abnormalities were revealed in myelin sheaths. Dense myelin is split into several layers at the intraperiod line, terminal loops being swollen. Proliferation of oligodendroglia is also observed. Most of the mitochondria, both in the glia and nervous fibers, almost completely lack cristae. Proportional relationship between two main components of the cytoskeleton, i.e. neurofilaments and microtubuli, increases, which may be taken as an indication of a compensatory reaction. The observed morphological changes may play significant role in disturbances of sleep-wakefulness cycle in rats with hereditary catatonia.