scholarly journals How neural stem cells contribute to neocortex development

2021 ◽  
Author(s):  
Lei Xing ◽  
Michaela Wilsch-Bräuninger ◽  
Wieland B. Huttner
Keyword(s):  
Cortical Neurons ◽  
Neural Progenitor Cells ◽  
Mammalian Species ◽  
Cellular Behavior ◽  
Cortical Neurogenesis ◽  
Biological Features ◽  
Neocortical Development ◽  
Proliferation And Differentiation ◽  
Different Types ◽  
Higher Cognitive Functions

The mammalian neocortex is the seat of higher cognitive functions, such as thinking and language in human. A hallmark of the neocortex are the cortical neurons, which are generated from divisions of neural progenitor cells (NPCs) during development, and which constitute a key feature of the well-organized layered structure of the neocortex. Proper formation of neocortex structure requires an orchestrated cellular behavior of different cortical NPCs during development, especially during the process of cortical neurogenesis. Here, we review the great diversity of NPCs and their contribution to the development of the neocortex. First, we review the categorization of NPCs into different classes and types based on their cell biological features, and discuss recent advances in characterizing marker expression and cell polarity features in the different types of NPCs. Second, we review the different modes of cell divisions that NPCs undergo and discuss the importance of the balance between proliferation and differentiation of NPCs in neocortical development. Third, we review the different proliferative capacities among different NPC types and among the same type of NPC in different mammalian species. Dissecting the differences between NPC types and differences among mammalian species is beneficial to further understand the development and the evolutionary expansion of the neocortex and may open up new therapeutic avenues for neurodevelopmental and psychiatric disorders.

scholarly journals Length of the Neurogenic Period—A Key Determinant for the Generation of Upper-Layer Neurons During Neocortex Development and Evolution

2021 ◽  
Vol 9 ◽  
Author(s):  
Barbara K. Stepien ◽  
Samir Vaid ◽  
Wieland B. Huttner
Keyword(s):  
Cognitive Abilities ◽  
Cortical Neurons ◽  
Mammalian Species ◽  
Critical Role ◽  
Exact Nature ◽  
Cortical Neurogenesis ◽  
Brain Functions ◽  
The Relationship ◽  
Development And Evolution

The neocortex, a six-layer neuronal brain structure that arose during the evolution of, and is unique to, mammals, is the seat of higher order brain functions responsible for human cognitive abilities. Despite its recent evolutionary origin, it shows a striking variability in size and folding complexity even among closely related mammalian species. In most mammals, cortical neurogenesis occurs prenatally, and its length correlates with the length of gestation. The evolutionary expansion of the neocortex, notably in human, is associated with an increase in the number of neurons, particularly within its upper layers. Various mechanisms have been proposed and investigated to explain the evolutionary enlargement of the human neocortex, focussing in particular on changes pertaining to neural progenitor types and their division modes, driven in part by the emergence of human-specific genes with novel functions. These led to an amplification of the progenitor pool size, which affects the rate and timing of neuron production. In addition, in early theoretical studies, another mechanism of neocortex expansion was proposed—the lengthening of the neurogenic period. A critical role of neurogenic period length in determining neocortical neuron number was subsequently supported by mathematical modeling studies. Recently, we have provided experimental evidence in rodents directly supporting the mechanism of extending neurogenesis to specifically increase the number of upper-layer cortical neurons. Moreover, our study examined the relationship between cortical neurogenesis and gestation, linking the extension of the neurogenic period to the maternal environment. As the exact nature of factors promoting neurogenic period prolongation, as well as the generalization of this mechanism for evolutionary distinct lineages, remain elusive, the directions for future studies are outlined and discussed.

scholarly journals Beyond Axon Guidance: Roles of Slit-Robo Signaling in Neocortical Formation

2020 ◽  
Vol 8 ◽  
Author(s):  
Yuko Gonda ◽  
Takashi Namba ◽  
Carina Hanashima
Keyword(s):  
Axon Guidance ◽  
Neural Progenitor Cells ◽  
Autism Spectrum ◽  
Extracellular Signaling ◽  
Neocortical Development ◽  
Neocortical Neurons ◽  
Proliferation And Differentiation ◽  
Progenitor Cell Proliferation ◽  
And Migration ◽  
Proliferation And Migration

The formation of the neocortex relies on intracellular and extracellular signaling molecules that are involved in the sequential steps of corticogenesis, ranging from the proliferation and differentiation of neural progenitor cells to the migration and dendrite formation of neocortical neurons. Abnormalities in these steps lead to disruption of the cortical structure and circuit, and underly various neurodevelopmental diseases, including dyslexia and autism spectrum disorder (ASD). In this review, we focus on the axon guidance signaling Slit-Robo, and address the multifaceted roles of Slit-Robo signaling in neocortical development. Recent studies have clarified the roles of Slit-Robo signaling not only in axon guidance but also in progenitor cell proliferation and migration, and the maturation of neocortical neurons. We further discuss the etiology of neurodevelopmental diseases, which are caused by defects in Slit-Robo signaling during neocortical formation.

Glycans in scaffold design in tissue reconstruction

2021 ◽  
pp. 088391152199784
Author(s):  
Nipun Jain ◽  
Shashi Singh
Keyword(s):  
Cell Attachment ◽  
Low Cost ◽  
Growth Conditions ◽  
Downstream Signaling ◽  
Cell Carrier ◽  
Wide Range ◽  
Proliferation And Differentiation ◽  
Different Types ◽  
Tissue Reconstruction ◽  
A Cell

Development of an artificial tissue by tissue engineering is witnessed to be one of the long lasting clarified solutions for the damaged tissue function restoration. To accomplish this, a scaffold is designed as a cell carrier in which the extracellular matrix (ECM) performs a prominent task of controlling the inoculated cell’s destiny. ECM composition, topography and mechanical properties lead to different types of interactions between cells and ECM components that trigger an assortment of cellular reactions via diverse sensing mechanisms and downstream signaling pathways. The polysaccharides in the form of proteoglycans and glycoproteins yield better outcomes when included in the designed matrices. Glycosaminoglycan (GAG) chains present on proteoglycans show a wide range of operations such as sequestering of critical effector morphogens which encourage proficient nutrient contribution toward the growing stem cells for their development and endurance. In this review we discuss how the glycosylation aspects are of considerable importance in everyday housekeeping functions of a cell especially when placed in a controlled environment under ideal growth conditions. Hydrogels made from these GAG chains have been used extensively as a resorbable material that mimics the natural ECM functions for an efficient control over cell attachment, permeability, viability, proliferation, and differentiation processes. Also the incorporation of non-mammalian polysaccharides can elicit specific receptor responses which authorize the creation of numerous vigorous frameworks while prolonging the low cost and immunogenicity of the substance.

Regulation of sperm motility at the axonemal level

1995 ◽  
Vol 7 (4) ◽  
pp. 847 ◽  
Author(s):  
C Gagnon
Keyword(s):  
Direct Action ◽  
Mammalian Species ◽  
Basic Structure ◽  
Structure And Function ◽  
Structural Components ◽  
Long Period ◽  
Different Types ◽  
Radial Spokes ◽  
Dynein Arms ◽  
And Function

With very few exceptions, the basic structure of the 9+2 axoneme has been well preserved over a very long period of evolution from protozoa to mammais. This stability indicates that the basic structural components of the axoneme visible by electron microscopy, as well as most of the other unidentified components, have withstood the passage of time. It also means that components of the 9+2 axoneme have sufficient diversity in function to accommodate the various types of motility patterns encountered in different species of flagella. Several of the 200 polypeptides that constitute the axoneme have been identified as components of the dynein arms, radial spokes etc. but many more remain to be identified and their function(s) remain to be determined. Because this review deals with the regulation of flagellar movement at the axonemal level, it does not include regulation of flagella by extracellular factors unless these factors have a direct action on axonemal components. In this context, it is very important firstly to understand the structural components of the axoneme and how they influence and regulate axonemal movement. Different primitive organisms are mentioned in this review since major breakthroughs in our understanding of how an axoneme generates different types of movement have been made through their study. Despite some variations in structure and function of axonemal components, the basic mechanisms involved in the regulation of flagella from Chlamydomonas or sea urchin spermatozoa should also apply to the more evolved mammalian species, including human spermatozoa.

scholarly journals Plasma Rich in Growth Factors in the Treatment of Endodontic Periapical Lesions in Adult Patients: A Narrative Review

2021 ◽  
Vol 14 (10) ◽  
pp. 1041
Author(s):  
Agata Zoltowska ◽  
Katarzyna Machut ◽  
Elzbieta Pawlowska ◽  
Marcin Derwich
Keyword(s):  
Growth Factors ◽  
Tissue Regeneration ◽  
Adult Patients ◽  
Application Site ◽  
Platelet Concentrates ◽  
Platelet Rich Fibrin ◽  
Periapical Lesions ◽  
Pubmed Database ◽  
Proliferation And Differentiation ◽  
Different Types

Platelet concentrates have been widely used in regenerative medicine, including endodontics. The aim of this manuscript was to assess critically the efficacy of PRF in the treatment of endodontic periapical lesions in adult patients on the basis of the literature. The PICO approach was used to properly develop literature search strategies. The PubMed database was analyzed with the keywords: “((PRP) OR (PRF) OR (PRGF) OR (CGF)) AND (endodontic) AND ((treatment) OR (therapy))”. After screening of 155 results, 14 articles were included in this review. Different types of platelet concentrates are able to stimulate the processes of proliferation and differentiation of mesenchymal stem cells. Platelet rich fibrin (PRF) releases growth factors for at least 7 days at the application site. Growth factors and released cytokines stimulate the activity of osteoblasts. Moreover, the release of growth factors accelerates tissue regeneration by increasing the migration of fibroblasts. It was not possible to assess the efficacy of PRF supplementation in the treatment of endodontic periapical lesions in permanent, mature teeth with closed apexes, due to the lack of well-designed scientific research. Further studies are needed to analyze the effect of PRF on the healing processes in the periapical region.

scholarly journals Using of tea-hybrid roses from the Nikita Botanical Gardens’ collection in the floriculture of the Southern Coast of the Crimea

2020 ◽  
pp. 65-77
Author(s):  
Z. K. Klimenko ◽  
S. A. Plugatar ◽  
V. K. Zykova ◽  
I. N. Kravchenko
Keyword(s):  
Optimal Timing ◽  
Southern Coast ◽  
Botanical Gardens ◽  
Biological Features ◽  
Different Types ◽  
Open Ground ◽  
The Crimea ◽  
Comprehensive Study

The article presents the results of a long-term research on the introduction study and evaluation of cultivars of tea-hybrid roses introduced and selected by the Nikitsky Botanical Gardens to determine the possibilities of their use in floriculture of the Southern Coast of the Crimea. The research was conducted in the period from 1955 to 2014. The material for the study was 679 cultivars of garden roses from the tea-hybrid garden group of the collection of the Nikitsky Botanical Gardens. As a result of a comprehensive study, 400 cultivars are recommended for use in the floriculture of the Crimea. The main options for this use becomes the growing of tea-hybrid roses in the open ground for gardening purposes in bush and tree-shaped forms, as well as the growing cultivars for cutting in both open and protected ground. The biological features of the cultivars, which determine the possibility of different types of the use and the cultivars, that have these features were identified: 400 cultivars were recommended for use in landscaping in bush form, 45 cultivars - also in tree-shaped form, 226 cultivars are promising for cutting in the open ground and 107 cultivars - for forcing and cutting in greenhouses. The main methods of propagation of cultivars of tea-hybrid roses under the conditions of the Southern Coast of the Crimea are budding and rooting of green and hardwood cuttings. The optimal timing for propagation by each of these methods is indicated. The best rootstocks for budding were identified, depending on the type of their use in floriculture. 

TWEAK regulates proliferation and differentiation of adult neural progenitor cells

2011 ◽  
Vol 46 (1) ◽  
pp. 325-332 ◽  
Author(s):  
Marion N. Schölzke ◽  
Amely Röttinger ◽  
Sasidhar Murikinati ◽  
Nadine Gehrig ◽  
Christoph Leib ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Neural Progenitor Cells ◽  
Neural Progenitor ◽  
Proliferation And Differentiation

scholarly journals miR-194-5p negatively regulates the proliferation and differentiation of rabbit skeletal muscle satellite cells

2020 ◽  
Author(s):  
Yu Shi ◽  
Xudong Mao ◽  
Mingcheng Cai ◽  
Shenqiang Hu ◽  
Xiulan Lai ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Satellite Cells ◽  
Mammalian Species ◽  
Muscle Growth ◽  
Luciferase Reporter ◽  
Stem Cell Population ◽  
Muscle Satellite Cells ◽  
Skeletal Muscle Satellite Cells ◽  
Proliferation And Differentiation

Abstract Skeletal muscle satellite cells (SMSCs), also known as a multipotential stem cell population, play a crucial role during muscle growth and regeneration. In recent years, numerous miRNAs have been associated with the proliferation and differentiation of SMSCs in a number of mammalian species; however, the regulatory mechanisms of miR-194-5p in rabbit SMSCs still remain scarce. In this study, miR-194-5p was first observed to be highly expressed in the rabbit leg muscle. Furthermore, both the mimics and inhibitor of miR-194-5p were used to explore its role in the proliferation and differentiation of rabbit SMSCs cultured in vitro. Results from both EdU and CCK8 assays showed that miR-194-5p inhibited the proliferation of SMSCs. Meanwhile, Mef2c was identified as a target gene of miR-194-5p based on the dual-luciferase reporter assay results. In addition, upregulation of miR-194-5p decreased the expression levels of Mef2c and MyoG during rabbit SMSCs differentiation on Days 3 and 7 of in vitro culture. Taken together, these data demonstrated that miR-194-5p negatively regulates the proliferation and differentiation of rabbit SMSCs by targeting Mef2c.

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