[Ultrastructure of glial-neuronal interrelationships in the celiac nodes of normal and hypokinetic rats].

Ultrastructure of perisomatic gliocytes and glio-neuronal interrelations were studied in celiac nodes in normal young (6 months) and old (28--30 months) rats and at 45-days' hypokinesia. Several variants on how deep gliocytes are situated in the perikaryon, their relation to neuronal processes, as well as the character of border-line membrane relations are described. It was stated that processes of gliocytes have varied relations with each other, with neuronal perikaryon, with neural fibres. In old animals some dystrophic changes were revealed in glio-neuronal complexes. At hypokinesia a wide range of dystrophic changes in all structural elements in the nodes and destruction of some glio-neuronal complexes were observed. These changes were more evident in the old animals and at early stages, but by the end of the experiment they notably subsided. Simultaneously, some qualitative rearrangements of glio-neuronal interrelations took place: the relief of contacting membranes grew complex at the expense of interdirected small processes and deep invaginations of gliocytic processes into the neuronal perikaryon; the number of layers in the glial capsule increased as a result of hyperplasia of perisomatic gliocytic processes migrating towards gliocytic neurons and lemmocytic processes. Variety of forms in the glio-neuronal interrelations evidence in favour of their high structural plasticity. At hypokinesia, great resources of gliocytes to plastic transformations, of compensatory-adaptive importance are realized. In the celiac nodes of the old animals the adaptive rearrangements of the glio-neuronal interrelations developed more slowly and with less efficiency than in the young animals.