[Transplantation of stem/progenitor cells of human brain into the brain of adult rats].

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 DNA content of the neurons in the embryonic cerebellum transplanted into the cerebral cortex of adult rats].

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 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].

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].

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).

[Changes in the brain neurons of the recipient around an embryonic nerve tissue transplant].

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.

[Nucleolus-like bodies and neuronal differentiation in the anterior hypothalamus of rats].

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.

[Ultrastructure of mitotically dividing cells with signs of neurons in the rat brain].

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.

[Ultrastructure of neurons manifested by hyperchromia and vacuolization observed in nerve tissue following hypoxia].

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.

[Electron microscopic and cytochemical research on the function of the glial cells in a focus of local cortical destruction].

The activity of DNA-RNA-protein synthesizing system of some glial cells was studied using electron cytochemical method for determination of chromatin state and RNA-particles. A dependence of functional state of satellite glial cells (oligodendroglia and astroglia) on the tinctorial neuron state (hyper- and hypochromic scale) was shown. The functional state of interfascicular oligodendroglial cells has been characterized.

[Ultrastructure of neurons with initial signs of ischemization in schizophrenia].

The authors studied two cases of sudden death of schizophrenia patients aged 23 and 40 years who died from acute asphyxia. Two types of ultrastructural changes in their cortical neurons are described: gradual lightening of the cytoplasm and nuclei in some cells; cytoplasm lightening, perinuclear edema and increased nuclear density due to condensed chromatin in others. Cytoplasm lightening is explained by swelling of the cysterns of the endoplasmatic reticulum and loss of polysomes.

[Neurons in the hyperchromic state].

The paper summarizes findings concerning the ultrastructure and cytochemistry of the cortical hyperchromic neurons which appear under different experimental conditions (in intact animals, in mechanical traumatization of neuronal tissue, during formation of a local focus of destruction, upon the administration of aminazine, and in the process of autolysis). Characteristics of the development of the hyperchromic status in each of the above experimental situations are specified. The authors consider the questions concerning the life-time development of neuronal hyperchromia, a relationship of hyperchromia with a certain function of the cell and the reversibility of the ultrastructural and cytochemical shifts characteristic of hyperchromia.

[Electron-cytochemical characteristics of hyperchromic neurons in schizophrenia].

During autopsy of brains from 17 schizophrenic patients and 14 mentally normal subjects the authors studied metabolic characteristics in hyperchromic neurons, using methods of electron cytochemistry. The parameters of plastic and energy metabolism investigated included ribonucleoproteins (RNP), Mg-activated ATPase and succinate dehydrogenase (SDH). Two types of neurons with a different degree of hyperchromia and a decrease in metabolic activity were identified.