Morphological, biochemical and physiological changes in brain nervous tissue of adult intact and hypoxia-subjected rats after transplantation of embryonic nervous tissue.

Data of morphological, biochemical and physiological investigations of brain nervous tissue in adult intact and hypoxia-subjected rats after transplantation of rat embryonic nervous tissue are presented. It has been established that transplants survive and develop successfully in the brain of both intact and hypoxia-subjected rats. The Golgi technique reveals that transplanted neurons form dendrites and axons. They also establish afferent and efferent connections with neurons in different brain regions of the recipient, as has been demonstrated by the horseradish peroxidase (HRP) tract tracing technique. Hypoxia induces reversible as well as irreversible dystrophy of host brain neurons, and transplantation of embryonic brain tissue leads to considerable normalization of the state of reversibly dystrophic neurons. Biochemical investigations have revealed that the spectrum of cytoplasmic proteins of neurons and proteins of the whole brain cortex tissue changed after hypoxia are significantly normalized after subsequent transplantation. It should be also pointed out that there is a considerable increase in the number of proteins in certain fractions which is correlated with regeneration of reversibly dystrophic neurons and other cortical cells. Electrophysiological experiments revealed distinct but short-term EEG changes induced by hypoxia. 1-2 days after hypoxia all EEG parameters were back to normal and displayed no changes during the 2-3-month registration period.