[Transplantation of stem/progenitor cells of human brain into the brain of adult rats]. / Transplantatsiia stvolovykh/progenitornykh kletok mozga cheloveka v mozg vzroslykh krys.

We studied the development of stem/progenitor cells of the human brain transplanted in the adult rat brain after reproduction in an in vitro tissue culture. It was preliminarily shown by the immunological methods that the stem cells grown in a medium with growth factors formed neurospheres, which were heterogenous and contained both stem and progenitor cells of the human brain. The cells were implanted in the hippocampus, striatum, or lateral ventricle of the rat brain as a suspension or aggregates (neurospheres) and their behavior and differentiation were studies within 10, 20, and 30 days using the morphological and immunochemical methods. The cultured cells of the human brain continued their development in the rat brain, migrated, and formed neurons and astrocytes. The white mater fibers, lateral ventricle wall, and perivascular spaces served as the main pathways of migration. The neuronal differentiation was shown by staining with antibodies to beta-tubulin III, neurofilaments-70, and calbindin. Some growing nerve cells had long processes with growth cones. At the same time, some transplanted cells retained the undifferentiated state within one month after the implantation, as shown by the vimentin expression.

[The DNA content of the neurons in the embryonic cerebellum transplanted into the cerebral cortex of adult rats]. / Soderzhanie DNK v neironakh émbrional'nogo mozzhechka, transplantirovannogo v koru golovnogo mozga vzroslykh krys.

Cerebellum of rat embryos at day 17 of gestation was transplanted into sensomotor cortex of adult syngenic rats. DNA content in granule and Purkinje cells of the transplant was determined cytophotometrically on day 30 after surgery. It is shown that granule cells are diploid; about 3% Purkinje cells contain hyperdiploid and tetraploid nuclei which corresponds to the content of such cells in the adult cerebellum. The conclusion is drawn that cell hyperploidy does not depend on the functional load but is essential property of the tissue.

The recovery of the ultrastructure of hyperchromic host neurons under the influence of fetal neurotransplants.

Fetal neocortical transplants placed into a previously prepared cavity in the cortex of adult animals inhibited destructive processes in host neurons surrounding the place of injury. This was demonstrated by a gradual reduction in the number of hyperchromic and shrunken host neurons and the recovery of the ultrastructure of dystrophic cells which die as a result of neuronophagia or sclerosis in the absence of the transplants.

[The effect of different methods of isolating thrombocytes on the surface structure and biochemical parameters of the serotonin system of these cells]. / Vliianie raznykh sposobov vydeleniia trombotsitov na poverkhnostnuiu strukturu i biokhimicheskie parametry serotoninovoi sistemy étikh kletok.

The method of platelets' isolation influences their morphofunctional state. The study of the surface structure of platelets with the method of scanning electron microscopy shows, that the nonactivated form of platelets is characterized for the cells, isolated by gel filtration, but platelets which are isolated by centrifugation are activated. Platelets' activation under centrifugation is shown to connect with the changes of biochemical parameters of platelet serotonin system: the increase of the velocity of the 3H-serotonin reuptake and of the 3H-imipramine specific binding.

[Plastic metabolism in neurons altered according to the hypochromic type]. / Plasticheskii obmen v neironakh pri ikh izmeneniiakh po gipokhromnomu tipu.

Ribonucleoprotein structures and condensed chromatin (CCh) have been studied electron cytochemically in neurons of the rat cerebral sensomotor cortex at their reversible (injection of aminazine) and irreversible (postmortem and posttraumatic processes) alterations according to the hypochromic type. For the hypochromic neurons, revealed after aminazine administration, increasing metabolic activity in their plastic apparatus is specific: intensification of the nuclear-cytoplasmic transport of RNA (decreasing amount of interchromatin granules and fibrils), when the acid synthesis is preserved, presence of small fibrillized clumps (SC), perichromatin fibrils (PChF); nucleolar structure is specific for the stage of active functioning. At the postmortem and posttraumatic alterations of the neurons according to the hypochromic type, the functional activity of the system DNA--RNA--protein in them is inhibited: mainly, the transcriptive activity of nuclei decreases (PChF, SC disappear and CCh appear). Combination of these processes with development of hydrolytic changes (nonidentified electron opaque material appears, CCh clumps and perichromatin granules undergo fibrillization, ribosomes decrease in their number) reflects certain irreversible lesions of hypochromic neurons.

[Changes in the brain neurons of the recipient around an embryonic nerve tissue transplant]. / Izmenenie neironov mozga retsipienta vokrug transplantata émbrional'noi nervnoi tkani.

Ultrastructure of adult neurons (sensomotor cortex) of recipient brain tissue localized in the vicinity of developing embryonic nervous tissue transplant has been studied. Partial dedifferentiation of pyramidal neurons has been revealed four days after the transplantation. The following changes were observed: dispersion and nearly complete absence of granular endoplasmic reticulum: appearance of a multitude of small mitochondria and disappearance of large ones; the presence of a large number of free polysomes; marked clearing of nuclei, and the presence of large nucleoli. No destructive processes in neurons were observed.

[Nucleolus-like bodies and neuronal differentiation in the anterior hypothalamus of rats]. / Iadrushkopodobnye te'ltsa i differentsirovka neironov perednego gipotalamusa krys.

The emergence of nucleolus-like bodies was studied during differentiation of neurosecretory hypothalamic neurons. Nucleus supraopticus was studied in offspring of intact rats and in offspring of mothers injected with anti-hypothalamic antibodies stimulating hypothalamic tissue differentiation during gestation. The degree of structural and functional differentiation of neurosecretory cells correlated with the number of neurosecretory cells and of neurons with nucleolus-like bodies. The authors believe that these bodies' formation is a physiological event linked to development of specific function of neurosecretory cells. Morphologically, nucleoli and nucleolus-like bodies were different, with nucleolonemms absent in the latter.

[Ultrastructure of mitotically dividing cells with signs of neurons in the rat brain]. / Ul'trastruktura mitoticheski deliashchikhsia kletok s priznakami neronov v mozge krys.

Ultrastructure of mitotically dividing cells in the sensomotor cerebral cortex of mature rats has been investigated, after transplantation into them embryonal nervous tissue of 17-day-old embryos. In 4 days after the operation in the recipient's nervous tissue, arranging around the developing transplant, among various proliferating cells with mitotic figures, some cells with signs of neurons (oval bodies, electron opaque cytoplasm with developed organelles and RNP-particles, specific for the nervous cell, with axonal terminals on the body) have been found. These cells are surrounded with the satellite glia. There are no mitotic figures in the pyramidal neurons.

[Ultrastructure of neurons manifested by hyperchromia and vacuolization observed in nerve tissue following hypoxia]. / Osobennosti ul'trastruktury neironov s iavleniiami giperkhromii i vakuolizatsii, obnaruzhivaemykh v nervnoi tkani posle gipoksii.

100 days after the exposure of the rat sensorimotor cortex to hypoxic hypoxia two types of hyperchromic neurons with vacuolization of the cytoplasm were described. Using electron cytochemical method for the differential staining of ribonucleoproteins, it has been shown that the first type of hyperchromic neurons were cells with irreversible dystrophic changes and the second type were cells without irreversible dystrophy but with changes in the DNA-RNA-protein synthesizing system.