Nerve fibre regeneration after traumatic lesions of the CNS; progress and problems

1991 ◽  
Vol 331 (1261) ◽  
pp. 303-306 ◽  
Keyword(s):  
Synapse Formation ◽  
Target Recognition ◽  
Side Branch ◽  
Distal Dendrite ◽  
Long Distance ◽  
Axon Sprouting ◽  
Lower Vertebrates ◽  
Traumatic Lesions ◽  
Branch Formation ◽  
Selection Of

Four distinct phases can be distinguished in the regenerative response of a lesioned CNS axon: sprouting of the proximal axon stump, elongation, target recognition, and formation of appropriate synapses. These processes can be observed in such a way only in lower vertebrates, in particular, in the optic system. In these species and systems, both, the guidance mechanisms leading regenerating fibres to their former target areas, and the mechanisms responsible for specific synapse formation are retained throughout life. As during development, guidance crucially depends on the presence of favourable substrate molecules, and on chemotropic signals (Dodd & Jessel 1989; Tessier-Lavigne et al .1988; Harris 1989). The cell biological mechanisms responsible for target recognition including the arrest of long-distance growth, the initiation of side branch formation and terminal arborization, and the selection of specific post-synaptic partners (cell type; soma, proximal or distal dendrite, spines, axons) remain unknown up to now.

Neuromuscular target recognition by a homophilic interaction of connectin cell adhesion molecules in Drosophila

Development ◽  
1997 ◽  
Vol 124 (8) ◽  
pp. 1433-1441 ◽  
Author(s):  
A. Nose ◽  
T. Umeda ◽  
M. Takeichi
Keyword(s):  
Cell Adhesion ◽  
Synapse Formation ◽  
Target Recognition ◽  
Surface Protein ◽  
Transgenic Lines ◽  
A Cell ◽  
Neuromuscular Connectivity ◽  
Recognition Molecule

Drosophila Connectin (CON) is a cell surface protein of the leucine-rich repeat family. During the formation of neuromuscular connectivity, CON is expressed on the surface of a subset of embryonic muscles and on the growth cones and axons of the motoneurons that innervate these muscles, including primarily SNa motoneurons and their synaptic targets (lateral muscles). In vitro, CON can mediate homophilic cell adhesion. In this study, we generated transgenic lines that ectopically expressed CON on all muscles. In the transformant embryos and larvae, SNa motoneurons often inappropriately innervated a neighboring non-target muscle (muscle 12) that ectopically expressed CON. Furthermore, the ectopic synapse formation was dependent on the endogenous CON expression on the SNa motoneurons. These results show that CON can function as an attractive and homophilic target recognition molecule in vivo.

scholarly journals Syncrip/hnRNP Q is required for activity-induced Msp300/Nesprin-1 expression and new synapse formation

2020 ◽  
Vol 219 (3) ◽  
Author(s):  
Joshua Titlow ◽  
Francesca Robertson ◽  
Aino Järvelin ◽  
David Ish-Horowicz ◽  
Carlas Smith ◽  
...  
Keyword(s):  
Single Molecule ◽  
Posttranscriptional Regulation ◽  
Rna Binding ◽  
Synapse Formation ◽  
Long Distance ◽  
Key Factor ◽  
Larval Neuromuscular Junction ◽  
Rnp Granules ◽  
Activity Dependent

Memory and learning involve activity-driven expression of proteins and cytoskeletal reorganization at new synapses, requiring posttranscriptional regulation of localized mRNA a long distance from corresponding nuclei. A key factor expressed early in synapse formation is Msp300/Nesprin-1, which organizes actin filaments around the new synapse. How Msp300 expression is regulated during synaptic plasticity is poorly understood. Here, we show that activity-dependent accumulation of Msp300 in the postsynaptic compartment of the Drosophila larval neuromuscular junction is regulated by the conserved RNA binding protein Syncrip/hnRNP Q. Syncrip (Syp) binds to msp300 transcripts and is essential for plasticity. Single-molecule imaging shows that msp300 is associated with Syp in vivo and forms ribosome-rich granules that contain the translation factor eIF4E. Elevated neural activity alters the dynamics of Syp and the number of msp300:Syp:eIF4E RNP granules at the synapse, suggesting that these particles facilitate translation. These results introduce Syp as an important early acting activity-dependent regulator of a plasticity gene that is strongly associated with human ataxias.

scholarly journals Prognostics and health management technology for radar system

2020 ◽  
Vol 309 ◽  
pp. 04009
Author(s):  
Yongle Lyu ◽  
Zhuo Pang ◽  
Chuang Zhou ◽  
Peng Zhao
Keyword(s):  
Model Building ◽  
Health Management ◽  
Radar System ◽  
Prognostics And Health Management ◽  
Failure Model ◽  
Long Distance ◽  
Maintenance System ◽  
Management Technology ◽  
Key Techniques ◽  
Selection Of

Information-based war in the future has a higher requirement to the maintenance and support ability of radar system. Prognostics and Health Management(PHM) technology represents the research hotspot of maintenance system, and following key techniques need to be resolved to research on the radar PHM technology such as the acquirement and selection of health information and fault signs of a radar’s electronical components, mass data warehousing and mining, fusion of multi-source test data and multi-field characteristic information, failure model building and forecasting, automatic decision-making on maintenance, and at the same time improving the self built-in test abilities of radar’s components based on the optimization of Design For Testability(DFT). The radar PHM technology has the trend of “built-in to integrate”, “together with DFT” and “long-distance and distributed”. However, subjected to radar’s complexity and current PHM technique level, radar PHM engineering still meets many challenges, but has bright future.

Environmental analysis in the selection of alternative corridors in a long-distance linear project: A methodological proposal

2006 ◽  
Vol 80 (3) ◽  
pp. 266-278 ◽  
Author(s):  
Alejandro J. Rescia ◽  
Elizabeth N. Astrada ◽  
Julieta Bono ◽  
Carlos A. Blasco ◽  
Paula Meli ◽  
...  
Keyword(s):  
Environmental Analysis ◽  
Long Distance ◽  
Selection Of

On the way from misery to happiness? A longitudinal perspective on economic migration and well-being

2018 ◽  
Vol 8 (3) ◽  
pp. 307-355
Author(s):  
Fabian Kratz
Keyword(s):  
Rural Areas ◽  
Urban Areas ◽  
Panel Study ◽  
Well Being ◽  
Long Distance ◽  
Economic Migration ◽  
Nationally Representative ◽  
Dynamic Relationships ◽  
Migration Type ◽  
Selection Of

Abstract The assessment of returns from migration lies at the very heart of migration research. While a growing body of literature examines the links between migration and well-being, dynamic relationships require further elaboration. Using the longest running, nationally representative panel study with information on well-being, the German Socio-Economic Panel (1985–2016) this article addresses two essential, as yet unresolved, questions: How does the favourable self-selection of economic migrants affect their well-being before relocation?How does the well-being of economic migrants develop when individuals approach migration, and thereafter? Results show that—although favourably selected regarding determinants of well-being—economically motivated migrants are not happier before relocating than those who stay. Furthermore, economic migration has a causal impact on well-being, net of both observed and unobserved differences between migrants and stayers. This impact is transitory for women and long-lasting for men. For men, the results corroborate the view that migration enables access to opportunity structures favouring the pursuit of individual happiness. Results also differ by migration type: While long-distance movers and return migrants show a period of depressed happiness before a move, these findings do not hold for short-distance and onward migrants. Furthermore, moving towards urban areas results in stronger permanent effects than moving towards rural areas.

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