Reorganization of the Ultrastructure of Neocortical Neurons in Rats Treated with Extracellular DNA

Abstract

Neuron ultrastructure in layers III–V of the cerebral cortex was studied in rats 24 h after i.p. (n = 3) or i.v. (n = 3) administration of extracellular DNA (ecDNA) at a dose of 7.7·10–5 g/kg. Plastic rearrangements of nuclear chromatin were seen, along with nucleolar hypertrophy, deep invaginations of the nuclear envelope, mitochondrial hyperplasia, and tight contact between mitochondria and other organelles, including nuclei, formation of tubulovesicular bodies in the cytoplasm which could promote the transport of synaptic vesicles to the presynaptic terminals of axons, and activation of the astrocyte glia. These data provide evidence that administration of ecDNA leads to ultrastructural rearrangements of neocortical neurons directed to activating protein synthesis, increasing the efficacy of synaptic transmission, and enhancing energy metabolism, which may promote repair and compensatory processes in ischemic brain pathology.