[Changes in the topography of various proteins in cultured neurons after selective injury of various cytoskeletal elements with neurotoxins]. / Izmeneniia topografii nekotorykh belkov vneshnei membrany kul'tiviruemykh neironov pri izbiratel'nom povrezhdenii razlichnykh élementov tsitoskeleta neirotoksinami.

The spinal cord and hippocampal primary cultures were incubated with three neurotoxins (separately) known to impair the main components of the cytoplasmic cytoskeleton: 1) colchicine blocking the repolymerization of microtubules, 2) cytochalasin preventing elongation of actin filaments, and 3) beta, beta'-iminodipropionitrile (IDPN), causing disorganisation of neurofilaments. The distribution of surface membrane molecules on the surface of the neurons was evaluated in the ultrastructural study after treatment with the neurotoxins on the 5th, 12th, and 15th days in vitro (DIV). On the 12 DIV, the density of immunogold labelled neural cell adhesion molecules (NCAM) on IDPN-treated hippocampal neurons increased 1.45 times comparing to the controls. On the 5 DIV, the density of WGA (wheat germ agglutinin)-binding membrane glycoproteins increased 2.09 times on colchicine-treated neurons, and 3.98 times on cytochalasin-treated ones, whereas on the 12 DIV, the increase was 3.28 and 2.72 times, respectively, as compared to the control cultures of the same age. These data provide insights into the mechanisms of neurodegenerative changes in the nerve cells and into the relationship between the cytoskeletal elements and the surface molecules on the neuronal plasmatic membrane.

[The cytoskeleton of cultured spinal cord cells from mouse embryos]. / Tsitoskelet kul'tiviruemykh kletok spinnogo mozga émbrionov myshi.

By means of monoclonal antibodies (fluorescein-isothiocyanate- and rhodamine-labelled) distribution and quantitative content of the main cytoskeleton proteins (actin, tubulin, neurofilamentous protein with the molecular mass of 160 kDa and glial fibrillar acid protein) has been studied in various types of the mouse embryos spinal cord cells, cultivated in monolayer. During the process of development of neurons tubulin displaces from the neuronal soma into its processes with its predominant concentration in some of them, which are probably more active functionally at certain stages of differentiation. The total amount of tubulin is supposed to remain stable during the neuron life time. Quantitative content and distribution of actin filaments in various types of the cells are different. Actin content in the neurons is much lower than in glial cells and fibroblasts. The major amount of protein (neurofilamentous, glial fibrillar acid protein) is concentrated in cell bodies and in proximal parts of the processes. The pattern of distribution of the cytoskeleton proteins in the spinal cord cells has been revealed.

[Quantitative characteristics and reconstruction of the surface topography of histochemical markers on the nerve cell plasmalemma]. / Chislennye kharakteristiki i rekonstruktsiia poverkhnostnoi topografii gistokhimicheskikh markerov na plazmalemme nervnykh kletok.

An electron microscopic study of topography of colloidal gold-bound lectins conjugating to glycocalix carbohydrate residues on the somatic membrane surface of the cultivated spinal neurons has been carried out. The quantitative procedures are suggested for analyzing the surface pattern of the markers: two stochastic functions are considered to correspond properly to the particle distribution observed in the electron micrograms. The analysis of these functions permits obtaining required numerical characteristics. The Monte Carlo reconstructing model is described, and results of its work (on the basis of the above experimental data) are demonstrated in the form of "averaged" surface topography of the studied markers within the membrane fragments bordered. Possible connection of the obtained data with cooperative properties of the membrane is discussed.

[Immunocytochemical study of the distribution of cytoskeletal proteins in cultured neurons of the spinal cord of mouse embryos]. / Immunotsitokhimicheskoe issledovanie raspredeleniia tsitoskeletnykh belkov v kul'tiviruemykh neironakh spinnogo mozga myshinykh émbrionov.

The distribution of tubulin, actin and neurofilamentous protein (molecular weight 160 kD) in the spinal cord neurons of mice embryos cultivated in monolayer was studied by means of monoclonal FITC- and rhodamine labeled antibodies. It was found that nerve cell development induced migration of tubulin from the neuronal soma to its processes. The tubulin filling in different processes was uneven at certain stages of cell differentiation. The actin content in the neuron was negligible. Its point concentration was observed along the neuronal processes in the vicinity of focal contacts with the lining cells. Main content of neurofilamentous protein is concentrated in the neuronal body and proximal parts of neurites. The results obtained present the pattern of distribution of cytoskeletal proteins in the spinal cord neurons.

[The cytoskeleton of nerve cells during their differentiation]. / Tsitoskelet nervnykh kletok v protsesse ikh differentsirovki.

Ultrastructural and cytochemical characteristics of cytoskeletal elements of the cell (microtubules, microfilaments and neurofilaments), their state and proportion in a mature neuron and at definite stages of its differentiation are analyzed. Structural and functional properties of microtubule-associated proteins are described with their distribution in different parts of the neuron and quantitative changes in the course of differentiation. Data from literature concerning functional significance of cytoskeletal elements of the neuron, their connections with electrically excitable surface membrane and participation of the cytoskeleton in pathological states of the nervous system are discussed.