Neuron dynamics on directional surfaces

Soft Matter ◽  
2019 ◽  
Vol 15 (48) ◽  
pp. 9931-9941
Author(s):  
Joao Marcos Vensi Basso ◽  
Ilya Yurchenko ◽  
Matthew R. Wiens ◽  
Cristian Staii
Keyword(s):  
Theoretical Approach ◽  
Neuronal Growth ◽  
Directional Surfaces ◽  
Neuron Dynamics

We quantify neuronal growth on substrates with controlled geometries and present a theoretical approach that describes the motion of axons.

scholarly journals Neuronal Growth and Formation of Neuron Networks on Directional Surfaces

Biomimetics ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 41
Author(s):  
Ilya Yurchenko ◽  
Matthew Farwell ◽  
Donovan D. Brady ◽  
Cristian Staii
Keyword(s):  
Network Formation ◽  
Nerve Repair ◽  
Critical Role ◽  
Axonal Growth ◽  
Neuronal Growth ◽  
Neural Repair ◽  
Geometrical Properties ◽  
Neuron Networks ◽  
Steering Mechanism ◽  
Directional Surfaces

The formation of neuron networks is a process of fundamental importance for understanding the development of the nervous system and for creating biomimetic devices for tissue engineering and neural repair. The basic process that controls the network formation is the growth of an axon from the cell body and its extension towards target neurons. Axonal growth is directed by environmental stimuli that include intercellular interactions, biochemical cues, and the mechanical and geometrical properties of the growth substrate. Despite significant recent progress, the steering of the growing axon remains poorly understood. In this paper, we develop a model of axonal motility, which incorporates substrate-geometry sensing. We combine experimental data with theoretical analysis to measure the parameters that describe axonal growth on micropatterned surfaces: diffusion (cell motility) coefficients, speed and angular distributions, and cell-substrate interactions. Experiments performed on neurons treated with inhibitors for microtubules (Taxol) and actin filaments (Y-27632) indicate that cytoskeletal dynamics play a critical role in the steering mechanism. Our results demonstrate that axons follow geometrical patterns through a contact-guidance mechanism, in which geometrical patterns impart high traction forces to the growth cone. These results have important implications for bioengineering novel substrates to guide neuronal growth and promote nerve repair.

Differential polarization imaging of sickled cells

1988 ◽  
Vol 46 ◽  
pp. 62-63
Author(s):  
Marcos F. Maestre
Keyword(s):  
Optical Properties ◽  
Theoretical Approach ◽  
Polarized Light ◽  
Polarization Microscopy ◽  
Spectroscopic Techniques ◽  
Polarization Imaging ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Microscopic Scale ◽  
Chiral Structures

Recently we have developed a form of polarization microscopy that forms images using optical properties that have previously been limited to macroscopic samples. This has given us a new window into the distribution of structure on a microscopic scale. We have coined the name differential polarization microscopy to identify the images obtained that are due to certain polarization dependent effects. Differential polarization microscopy has its origins in various spectroscopic techniques that have been used to study longer range structures in solution as well as solids. The differential scattering of circularly polarized light has been shown to be dependent on the long range chiral order, both theoretically and experimentally. The same theoretical approach was used to show that images due to differential scattering of circularly polarized light will give images dependent on chiral structures. With large helices (greater than the wavelength of light) the pitch and radius of the helix could be measured directly from these images.

Historic memory and propaganda. A theoretical approach to the communicative study of memory

2016 ◽  
Vol 0 (26) ◽  
pp. 71-94 ◽  
Author(s):  
Miguel Vázquez Liñán ◽  
◽  
Salvador Leetoy ◽  
Keyword(s):  
Theoretical Approach ◽  
Historic Memory

Toxic Leadership in the Military Organization – A Theoretical Approach to Failed Leadership

2020 ◽  
Vol 26 (1) ◽  
pp. 182-185
Author(s):  
Alexandru Baboș ◽  
Raluca Rusu
Keyword(s):  
Cultural Differences ◽  
Theoretical Approach ◽  
Personal Characteristics ◽  
Toxic Leadership ◽  
Military Organization ◽  
The Military

AbstractThe toxic leadership refers to destructive behaviours and leaders’ personal characteristics which cause serious damage to the subordinates and organizations. Still, what is toxic for the military in one country can be good in another one, given the cultural differences. This article wants to emphasize, from a theoretical approach, the main characteristics and effects of toxic leadership within the military organization.

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