[Early postanoxic changes in the neuronal and neuropil ultrastructure of the cerebral cortex in cats].

Seven min after anoxia lasting for 2.5 and 6 min, changes in neurons and neuropil of the cat cerebral cortex sensomotor area have been studied electron microscopically. By means of a microscope MCCO having a long focus, the state of blood microcirculation in the pia mater vessels has been visually observed. During early postanoxic period, peculiar changes are mainly observed in neuronal bodies and degree of their manifestation depends on duration of the proceeding oxygen deficiency. In neuronal cytoplasm clearance of matrix, disorganization of the endoplasmic reticulum cisterns and formation of lamellar bodies are observed, as well as hypertrophy of Golgi complex and increasing number of free ribosomes. In the bodies of large pyramidal neurons of V layer, conglomerates of lipofuscin granules appear. In dendrites and myelinated axons destruction of membrane complexes and formation of myelin-like bodies are noted. In neuroglia glycogen granules precipitate. The most pronounced changes are revealed near microvessels which are filled with cellular blood elements. When estimating the ultrastructural changes of the cerebral cortex during early postanoxic period, it is necessary to take into account both duration of oxygen deficiency and the state of the blood microcirculation in various cortical areas.