BDNF and NT-3 Increase Velocity of Activity Front Propagation in Unidimensional Hippocampal Cultures

2010 ◽  
Vol 104 (6) ◽  
pp. 2932-2939 ◽  
Author(s):  
Shimshon Jacobi ◽  
Jordi Soriano ◽  
Elisha Moses
Keyword(s):  
Chronic Treatment ◽  
Synaptic Connection ◽  
Front Propagation ◽  
Excitatory Input ◽  
Synaptic Delay ◽  
One Dimensional ◽  
Propagation Front ◽  
Connection Probability ◽  
Neurotrophin 3 ◽  
Hippocampal Cultures

Neurotrophins are known to promote synapse development as well as to regulate the efficacy of mature synapses. We have previously reported that in two-dimensional rat hippocampal cultures, brain-derived neurotrophic factor (BDNF) and neurotrophin-3 significantly increase the number of excitatory input connections. Here we measure the effect of these neurotrophic agents on propagating fronts that arise spontaneously in quasi-one-dimensional rat hippocampal cultures. We observe that chronic treatment with BDNF increased the velocity of the propagation front by about 30%. This change is attributed to an increase in the excitatory input connectivity. We analyze the experiment using the Feinerman–Golomb/Ermentrout–Jacobi/Moses–Osan model for the propagation of fronts in a one-dimensional neuronal network with synaptic delay and introduce the synaptic connection probability between adjacent neurons as a new parameter of the model. We conclude that BDNF increases the number of excitatory connections by favoring the probability to form connections between neurons, but without significantly modifying the range of the connections (connectivity footprint).

BDNF and NT-3 increase excitatory input connectivity in rat hippocampal cultures

2009 ◽  
Vol 30 (6) ◽  
pp. 998-1010 ◽  
Author(s):  
Shimshon Jacobi ◽  
Jordi Soriano ◽  
Menahem Segal ◽  
Elisha Moses
Keyword(s):  
Excitatory Input ◽  
Hippocampal Cultures

Front propagation in the one-dimensional autocatalyticA+B→2Areaction with decay

1999 ◽  
Vol 59 (3) ◽  
pp. 2561-2565 ◽  
Author(s):  
V. N. Kuzovkov ◽  
J. Mai ◽  
I. M. Sokolov ◽  
A. Blumen
Keyword(s):  
Front Propagation ◽  
One Dimensional ◽  
The One

Propagation of spiking regularity in feedforward networks with recurrent connections

2021 ◽  
pp. 2150101
Author(s):  
Tianshi Gao ◽  
Bin Deng ◽  
Jixuan Wang ◽  
Jiang Wang ◽  
Guosheng Yi
Keyword(s):  
Synaptic Weight ◽  
Synaptic Connection ◽  
Feedforward Networks ◽  
Critical Window ◽  
Connection Probability ◽  
Visual Areas ◽  
Circuit Structure ◽  
Cortical Circuit ◽  
Recurrent Connections

The regularity of the inter-spike intervals (ISIs) gives a critical window into how the information is coded temporally in the cortex. Previous researches mostly adopt pure feedforward networks (FFNs) to study how the network structure affects spiking regularity propagation, which ignore the role of local dynamics within the layer. In this paper, we construct an FFN with recurrent connections and investigate the propagation of spiking regularity. We argue that an FFN with recurrent connections serves as a basic circuit to explain that the regularity increases as spikes propagate from middle temporal visual areas to higher cortical areas. We find that the reduction of regularity is related to the decreased complexity of the shared activity co-fluctuations. We show in simulations that there is an appropriate excitation–inhibition ratio maximizing the regularity of deeper layers. Furthermore, it is demonstrated that collective temporal regularity in deeper layers exhibits resonance-like behavior with respect to both synaptic connection probability and synaptic weight. Our work provides a critical link between cortical circuit structure and realistic spiking regularity.

scholarly journals Propagation of combustion waves in the shell–core energetic materials with external heat losses

2017 ◽  
Vol 473 (2199) ◽  
pp. 20160937
Author(s):  
V. V. Gubernov ◽  
V. N. Kudryumov ◽  
A. V. Kolobov ◽  
A. A. Polezhaev
Keyword(s):  
Solid Fuel ◽  
Energetic Materials ◽  
Energetic Material ◽  
Front Propagation ◽  
Heat Losses ◽  
Combustion Waves ◽  
One Dimensional ◽  
The One ◽  
Composite Solid ◽  
Linear Stability Problem

In this paper, the properties and stability of combustion waves propagating in the composite solid energetic material of the shell–core type are numerically investigated within the one-dimensional diffusive-thermal model with heat losses to the surroundings. The flame speed is calculated as a function of the parameters of the model. The boundaries of stability are determined in the space of parameters by solving the linear stability problem and direct integration of the governing non-stationary equations. The results are compared with the characteristics of the combustion waves in pure solid fuel. It is demonstrated that a stable travelling combustion wave solution can exist for the parameters of the model for which the flame front propagation is unstable in pure solid fuel and it can propagate several times faster even in the presence of significant heat losses.

Nonlinear Behaviour of Mass Transfer Mechanisms in Solvent Oil Recovery

2017 ◽  
Vol 379 ◽  
pp. 181-188 ◽  
Author(s):  
Shelley Lorimer ◽  
Caine Smithaniuk
Keyword(s):  
Mass Transfer ◽  
Front Propagation ◽  
Nonlinear Effects ◽  
Simulation Software ◽  
Solvent Recovery ◽  
One Dimensional ◽  
Solvent Front ◽  
Recovery Processes ◽  
And Diffusion ◽  
Transfer Mechanisms

Literature has indicated that, experimentally, solvent fronts in hybrid thermal solvent recovery processes progress more rapidly than what can be predicted using current approximations and more rapidly than thermal processes alone [1]. The equations that govern thermal multiphase flow through porous media are extremely complex and it is very difficult to decouple the contribution of the mass transfer mechanisms from the thermal effects. This paper explores the behavior of the mass transfer mechanisms in these processes through an examination of the nonlinear one-dimensional advection diffusion/dispersion (ADD) equation using finite difference methods. Earlier work [2] indicated that the linear ADD equation, using physically estimated parameters for diffusion and dispersion coefficients obtained from the literature, could not account for the solvent front progression rate predicted by Edmunds [3]. The results in this preliminary study indicate that the nonlinear effects are important in predicting the progression of a solvent front using the one dimensional ADD equation. The shapes and rate of propagation of the concentration profiles are influenced by both velocity and diffusion functionality. These results are more consistent with the solvent front propagation rate predicted by Edmunds [3]. These results also suggest that including nonlinear effects in traditional reservoir simulation software may be necessary in the modeling of solvent processes. Further work is needed to explore and understand the influence of the velocity and diffusion functionality necessary to mimic the behaviour observed in thermal solvent recovery processes and to further increase the understanding of their impact on solvent front propagation.

scholarly journals Motor cortex can directly drive the globus pallidus neurons in a projection neuron type-dependent manner in the rat

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Fuyuki Karube ◽  
Susumu Takahashi ◽  
Kenta Kobayashi ◽  
Fumino Fujiyama
Keyword(s):  
Basal Ganglia ◽  
Motor Cortex ◽  
Globus Pallidus ◽  
Projection Neuron ◽  
Excitatory Input ◽  
Morphological Observation ◽  
Dependent Manner ◽  
Motor Behaviors ◽  
Connection Probability ◽  
Motor Loop

The basal ganglia are critical for the control of motor behaviors and for reinforcement learning. Here, we demonstrate in rats that primary and secondary motor areas (M1 and M2) make functional synaptic connections in the globus pallidus (GP), not usually thought of as an input site of the basal ganglia. Morphological observation revealed that the density of axonal boutons from motor cortices in the GP was 47% and 78% of that in the subthalamic nucleus (STN) from M1 and M2, respectively. Cortical excitation of GP neurons was comparable to that of STN neurons in slice preparations. FoxP2-expressing arkypallidal neurons were preferentially innervated by the motor cortex. The connection probability of cortico-pallidal innervation was higher for M2 than M1. These results suggest that cortico-pallidal innervation is an additional excitatory input to the basal ganglia, and that it can affect behaviors via the cortex-basal ganglia-thalamus motor loop.

FLAME PROPAGATION IN ONE-DIMENSIONAL STATIONARY ERGODIC MEDIA

2007 ◽  
Vol 17 (01) ◽  
pp. 155-169 ◽  
Author(s):  
L. A. CAFFARELLI ◽  
K.-A. LEE ◽  
A. MELLET
Keyword(s):  
Free Boundary ◽  
Boundary Problem ◽  
Combustion Rate ◽  
Traveling Waves ◽  
Random Media ◽  
Front Propagation ◽  
Periodic Case ◽  
One Dimensional ◽  
A Free Boundary Problem ◽  
Effective Speed

This paper investigates front propagation in random media for a free boundary problem arising in combustion theory. We show the existence of asymptotic traveling waves solutions with effective speed depending only on the essential infimum of the combustion rate. This result generalizes a previous result of the same authors in the periodic case.

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