scholarly journals MICROGLIA AND ASTROCYTES OF THE HUMAN BRAIN SUBSTANTIA NIGRA

2019 ◽  
Vol 19 (1S) ◽  
pp. 135-135
Author(s):  
D E Korzhevskii ◽  
D A Sufieva ◽  
M A Brovko
Keyword(s):  
Substantia Nigra ◽  
Human Brain ◽  
Structural Organization ◽  
Active Role ◽  
Microglial Cells ◽  
Experimental Medicine ◽  
Special Role ◽  
Saint Petersburg ◽  
Close Proximity

In recent years, attention of researches has focused on glial cells of different brain formations - astrocytes and microglial cells. This is due to active role of these cells in ensuring synaptic plasticity and regulation of neurogenesis. The study aimed at analyzing the structural organization of microglia and astrocytes of the human brain substantia nigra, which is the main dopaminergic nerve center. For the study, material from the archive of the Morphology Department (Institute of Experimental Medicine, Saint Petersburg, Russia) was used. Cells were detected using immunocytochemical markers (GFAP for astrocytes and Iba-1 for microglia). It has been established that microglial cells bodies in substantia nigra are located in neuropile singly. In pars compacta of substantia nigra these cells distributed relatively evenly, rarely being in close proximity to neurons. An unexpected fact was that the processes of microglia cells of the human brain substantia nigra have a sufficiently large thickness - 1.5-3 microns, which is not typical for a ramified microglia. Astrocytes of substantis nigra were characterized by the presence of very long processes (more than 100 microns) and the formation of the pericellular sheath around the nerve cells. These sheaths consisted of a dense interweaving of thin sparingly branched astrocyte processes. The processes of microglia were rarely present within such sheaths. The results obtained indicate moderate activation of microglia in substantia nigra and the special role of astrocytes in ensuring the compartmentalization of the pericellular zones in this nerve center.

CERAMICS BASED ON ORGANOSILICON POLYMERS-PRECURSORS: MICROSTRUCTURE AND PROPERTIES (review). Part 2

2021 ◽  
pp. 22-32
Author(s):  
A.M. Shestakov ◽  
Keyword(s):  
Electron Microscopy ◽  
Nmr Spectroscopy ◽  
Material Properties ◽  
Structural Organization ◽  
Ceramic Materials ◽  
Special Role ◽  
Correct Interpretation ◽  
Instrumental Methods ◽  
Organosilicon Polymers

Shows the scientific approaches of various authors to the study of the microstructure of ceramics, the purpose of which is to elucidate its structural organization at the micro- and nanoscale, as well as the influence of the microstructure on the complex of material properties. Various instrumental methods for studying ceramics (NMR spectroscopy, electron microscopy, х-ray structural analysis, etc.) are considered, the permissible capabilities of research methods and analysis of the results obtained with their correct interpretation are shown. The special role of theoretical modeling in understanding the structure of the considered ceramic materials is noted.

A special role of water in dielectrics of different structural organization

2021 ◽  
Vol 585 (1) ◽  
pp. 40-51
Author(s):  
Nadezhda D. Gavrilova ◽  
Inna A. Malyshkina ◽  
Olga D. Novik
Keyword(s):  
Structural Organization ◽  
Special Role

scholarly journals Estradiol Inhibits Human Brain Vascular Pericyte Migration Activity: A Functional and Transcriptomic Analysis

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2314
Author(s):  
Lisa Kurmann ◽  
Michal Okoniewski ◽  
Raghvendra K. Dubey
Keyword(s):  
Endothelial Cells ◽  
Cell Migration ◽  
Human Brain ◽  
Neurovascular Unit ◽  
Active Role ◽  
Migration Activity ◽  
Akt Phosphorylation ◽  
And Function ◽  
The Impact

Stroke is the third leading cause of mortality in women and it kills twice as many women as breast cancer. A key role in the pathophysiology of stroke plays the disruption of the blood–brain barrier (BBB) within the neurovascular unit. While estrogen induces vascular protective actions, its influence on stroke remains unclear. Moreover, experiments assessing its impact on endothelial cells to induce barrier integrity are non-conclusive. Since pericytes play an active role in regulating BBB integrity and function, we hypothesize that estradiol may influence BBB by regulating their activity. In this study using human brain vascular pericytes (HBVPs) we investigated the impact of estradiol on key pericyte functions known to influence BBB integrity. HBVPs expressed estrogen receptors (ER-α, ER-β and GPER) and treatment with estradiol (10 nM) inhibited basal cell migration but not proliferation. Since pericyte migration is a hallmark for BBB disruption following injury, infection and inflammation, we investigated the effects of estradiol on TNFα-induced PC migration. Importantly, estradiol prevented TNFα-induced pericyte migration and this effect was mimicked by PPT (ER-α agonist) and DPN (ER-β agonist), but not by G1 (GPR30 agonist). The modulatory effects of estradiol were abrogated by MPP and PHTPP, selective ER-α and ER-β antagonists, respectively, confirming the role of ER-α and ER-β in mediating the anti-migratory actions of estrogen. To delineate the intracellular mechanisms mediating the inhibitory actions of estradiol on PC migration, we investigated the role of AKT and MAPK activation. While estradiol consistently reduced the TNFα-induced MAPK and Akt phosphorylation, only the inhibition of MAPK, but not Akt, significantly abrogated the migratory actions of TNFα. In transendothelial electrical resistance measurements, estradiol induced barrier function (TEER) in human brain microvascular endothelial cells co-cultured with pericytes, but not in HBMECs cultured alone. Importantly, transcriptomics analysis of genes modulated by estradiol in pericytes showed downregulation of genes known to increase cell migration and upregulation of genes known to inhibit cell migration. Taken together, our findings provide the first evidence that estradiol modulates pericyte activity and thereby improves endothelial integrity.

Iron and ferritin in hippocampal cortex and substantia nigra in human brain — Implications for the possible role of iron in dementia

2006 ◽  
Vol 248 (1-2) ◽  
pp. 31-34 ◽  
Author(s):  
Andrzej Friedman ◽  
Jolanta Galazka-Friedman ◽  
Erika R. Bauminger ◽  
Dariusz Koziorowski
Keyword(s):  
Substantia Nigra ◽  
Human Brain

scholarly journals THE ROLE OF STUDENT YOUTH IN THE CONSTRUCTION OF ANTI-CORRUPTION CIVIL SOCIETY: ILLUSION OR REALITY?

2020 ◽  
Vol 3 (1) ◽  
pp. 69-75
Author(s):  
Tatiana N. Akulova ◽  
Nadejda V. Plaksina ◽  
Elena V. Smirnova
Keyword(s):  
Civil Society ◽  
Negative Attitude ◽  
Social Institutions ◽  
Active Role ◽  
Public Confidence ◽  
Special Role ◽  
New Type ◽  
The Government ◽  
Near Future

  The article discusses the role and participation of students in building a «new» type of civil society from the perspective of an anti-corruption component. According to the authors, the most important criterion for the structure and construction of statehood is the propaganda of a negative attitude to corruption as a phenomenon that undermines public confidence in government bodies, government institutions, and public social institutions. The problem of the fight against corruption is relevant and at the present stage of the formation of our state requires active role participation. An important role and significance is assigned to students in the formation of the basic and key areas of modern state strategies in the anti-corruption vector. The authors substantiate the special role of students in the construction of a new formation by the absence of stable stereotypes due to age. The article presents and analyzes the results of a study on the attitude of students to fundamental changes in the Government of the Russian Federation, reveals ideas about the program for the development of the state and society in the near future from the perspective of students' opinions.

Colonization of Neural Allografts by Host Microglial Cells: Relationship to Graft Neovascularization

1997 ◽  
Vol 6 (3) ◽  
pp. 221-230 ◽  
Author(s):  
Nathan A. Pennell ◽  
Wolfgang J. Streit
Keyword(s):  
Blood Vessels ◽  
Great Majority ◽  
Active Role ◽  
Microglial Cells ◽  
Sprague Dawley ◽  
Functional Roles ◽  
Sprague Dawley Rats ◽  
Close Proximity ◽  
Quantitative Image ◽  
Phenotype Characteristic

In order to illuminate functional roles of microglial cells within neural allografts, we have transplanted both whole and microglial and endothelial cell-depleted E14 neural cell suspensions into the intact striatum of Sprague-Dawley rats. Following posttransplantation times of up to 30 days, the intrastrial allografts were analyzed histochemically using the Griffonia simplicifolia B4 isolectin, a marker for both microglia and blood vessels. Our results indicate that both whole and depleted suspension grafts develop identically in terms of neovascularization and microglial colonization. In both types of transplants microglial cells appeared before any blood vessels were apparent. The main phase of graft vascularization occurred between days 7 and 10 posttransplantation and neovascularization was complete by day 21, as revealed by quantitative image analysis. Microglial cells, which were present as ameboid cells during early posttransplantation times, underwent continuing cell differentiation with time that paralleled graft vascular development. By 30 days posttransplantation microglia within the grafts had assumed the fully ramified phenotype characteristic of resting adult microglia. During graft development and vascularization, microglia were often seen in close proximity to ingrowing blood vessels and vascular sprouts. In conclusion, our study has shown that microglial colonization of grafts and graft vascularization occurs independent of donor-derived microglial and endothelial cells, and suggests that the great majority of microglia and vessels within the graft are host derived. We hypothesize that the host microglia invading the allografts play an active role in promoting graft neovascularization.

scholarly journals Junctional ER Organization Affects Mechanotransduction at Cadherin-Mediated Adhesions

2021 ◽  
Vol 9 ◽  
Author(s):  
Michelle Joy-Immediato ◽  
Manuel J. Ramirez ◽  
Mauricio Cerda ◽  
Yusuke Toyama ◽  
Andrea Ravasio ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Actin Cytoskeleton ◽  
Structural Organization ◽  
Adherens Junctions ◽  
Conformational State ◽  
Microtubule Network ◽  
Close Proximity ◽  
Actomyosin Cytoskeleton

Cadherin-mediated adhesions (also known as adherens junctions) are adhesive complexes that connect neighboring cells in a tissue. While the role of the actin cytoskeleton in withstanding tension at these sites of contact is well documented, little is known about the involvement of microtubules and the associated endoplasmic reticulum (ER) network in cadherin mechanotransduction. Therefore, we investigated how the organization of ER extensions in close proximity of cadherin-mediated adhesions can affect such complexes, and vice versa. Here, we show that the extension of the ER to cadherin-mediated adhesions is tension dependent and appears to be cadherin-type specific. Furthermore, the different structural organization of the ER/microtubule network seems to affect the localization of ER-bound PTP1B at cadherin-mediated adhesions. This phosphatase is involved in the modulation of vinculin, a molecular clutch which enables differential engagement of the cadherin-catenin layer with the actomyosin cytoskeleton in response to tension. This suggests a link between structural organization of the ER/microtubule network around cadherin-specific adhesions, to control the mechanotransduction of adherens junctions by modulation of vinculin conformational state.

scholarly journals Field and scholarly studies of calendar folklore of Novgorod region: results and prospects

2020 ◽  
pp. 75-86
Author(s):  
Inga Korolkova
Keyword(s):  
Field Studies ◽  
Special Role ◽  
North West ◽  
Saint Petersburg ◽  
North East ◽  
The North ◽  
South West ◽  
The 1960S ◽  
Made In

The article focuses on calendar-ceremonial folklore of Novgorod region as an important component of folklore song traditions of the region. The musical and poetical forms of the calendar are considered in terms of type, genre and realm. The author is the first to systematize the data about calendar folklore recordings made in Novgorod region by various collectors in the 1960s - 1990s. The author gives special attention to the results of field studies of Saint Petersburg Conservatory named after N.A. Rimski-Korsakov. The author introduces into scientific discourse a range of items of calendar folklore from the archive of the Conservatory (Maslenitsa, Christmas and Easter carols and yells). The specificity of Novgorod calendar traditions is connected with a special role of intoned yells serving a function of calling over ceremonial characters, and Christmas carols combining the features of folk and church melodics. Some folklore forms, recorded in Novgorod region, can be considered unique (the North-East Maslenitsa chants, the “Piper” song, the Easter callings). Taking into account the peculiarities of a genre composition of the calendar, the types of chants and the style features, the author outlines three historical-cultural zones in Novgorod region - the North-East, the South-West and the Central. The research results can be used for mapping  the calendar folklore chants of Russia’s North-West, and for the further study of music folklore traditions of Novgorod region together with other folklore genres.   

READING AS COMMUNICATION: THREATS AND OPPORTUNITIES FOR TRANSFORMATION OF THE MODERN READER’S PERSONALITY

2020 ◽  
pp. 135-150
Author(s):  
O. M. Kolyshko
Keyword(s):  
Strong Dependence ◽  
Active Role ◽  
General Level ◽  
Special Role ◽  
The Core ◽  
Loss Of Self ◽  
Core Subjects ◽  
The Individual ◽  
Internet Reading

The article presents an analysis of reading subjects. Reading is defined as complex, non-line poly-subject and inter-subject communication. The author of the text, the reader, and the text are defined as the core subjects of reading. The field of reading realization is defined as the consciousness of the individual as a dialogic education by its nature. The ways of participation of each of the reading subjects in the process of interaction with each other are indicated. The author reveals the active role of the publisher in reading, social and cultural-historical contexts, the history and structure of the text, and the form of its carrier. The special role of the teacher in modern practices of educational reading is noted. The nature of participation in modern Internet reading of hypertext space is considered. Based on the author’s research, the threats and opportunities of reading for the personal transformation of the reader are described. As threats to reading for the reader, we can mention superficial communication and replacing the content of the text with their own ideas and ways of presenting them (reproducing themselves); strong exposure to influence from the text and the author’s position (losing yourself). It is indicated that educational reading is characterized by a strong dependence of the reader on the attitudes and interpretations of the teacher (loss of self). The integrative characteristic of the reader as a subject of reading-communication is determined by his reading strategy, which reflects the General level of reader culture. The developing mechanism of the personality in reading is the recognition and acceptance of “the other as different from the reader”, sensitivity to cultural and personal differences. The prospects for studying reading in the field of experimental research of reading mechanisms and the development of psychological and educational programs for the formation of reading competencies are outlined.

Sign in / Sign up

Export Citation Format

Share Document