Sophie Roth

Publications (4)12.44 Total impact

• Article: Neuronal architectures with axo-dendritic polarity above silicon nanowires.

  Sophie Roth, Ghislain Bugnicourt, Mariano Bisbal, Sylvie Gory-Fauré, Jacques Brocard, Catherine Villard
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  ABSTRACT: An approach is developped to gain control over the polarity of neuronal networks at the cellular level by physically constraining cell development by the use of micropatterns. It is demonstrated that the position and path of individual axons, the cell extension that propagates the neuron output signal, can be chosen with a success rate higher than 85%. This allows the design of small living computational blocks above silicon nanowires.
  Small 03/2012; 8(5):671-5. · 8.35 Impact Factor
• Source

  Available from: PubMed Central

  Article: How morphological constraints affect axonal polarity in mouse neurons.

  Sophie Roth, Mariano Bisbal, Jacques Brocard, Ghislain Bugnicourt, Yasmina Saoudi, Annie Andrieux, Sylvie Gory-Fauré, Catherine Villard
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  ABSTRACT: Neuronal differentiation is under the tight control of both biochemical and physical information arising from neighboring cells and micro-environment. Here we wished to assay how external geometrical constraints applied to the cell body and/or the neurites of hippocampal neurons may modulate axonal polarization in vitro. Through the use of a panel of non-specific poly-L-lysine micropatterns, we manipulated the neuronal shape. By applying geometrical constraints on the cell body we provided evidence that centrosome location was not predictive of axonal polarization but rather follows axonal fate. When the geometrical constraints were applied to the neurites trajectories we demonstrated that axonal specification was inhibited by curved lines. Altogether these results indicated that intrinsic mechanical tensions occur during neuritic growth and that maximal tension was developed by the axon and expressed on straight trajectories. The strong inhibitory effect of curved lines on axon specification was further demonstrated by their ability to prevent formation of multiple axons normally induced by cytochalasin or taxol treatments. Finally we provided evidence that microtubules were involved in the tension-mediated axonal polarization, acting as curvature sensors during neuronal differentiation. Thus, biomechanics coupled to physical constraints might be the first level of regulation during neuronal development, primary to biochemical and guidance regulations.
  PLoS ONE 01/2012; 7(3):e33623. · 4.09 Impact Factor
• Source

  Available from: Guillaume Becq

  Article: Recording and simulation of hippocampal neural networks with bicuculline

  Guillaume Becq, Sophie Roth, Steeve Zozor, Jacques Brocard, Sylvie Gory-Fauré, Pierre-Olivier Amblard, Catherine Villard
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  ABSTRACT: In this study we compare the neural activity of a population of neurons recorded with a MEA to simulations of equivalent networks obtained on a computer when bicuculline, an antagonist of inhibitory connections, is introduced into the nutritive solution. The aim of this study is to obtain a model producing extra-cellular data that match the synchronicity of two different real networks: a cell culture and an oraganotypic hippocampus slice. A one compartment model of neuron and a neuron-electrode model are used to simulate experiments. Parameters of the models are fitted to match in vivo data. It is shown that the variation of the noise level at the synaptic level induces a variation in the period of the bursting effect of bicuculline and produces variation in amplitude of the recorded signal.
• Source

  Available from: Guillaume Becq

  Article: Simulation of hippocampal neural networks under bicuculline, with noise and synaptic delays

  Guillaume Becq, Pierre-Olivier Amblard, Sophie Roth, Catherine Villard
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  ABSTRACT: When bicuculline an antagonist of inhibitory connections is introduced in the nutritive solution of an in vivo preparation containing neural networks, a synchronous activity of the neural network is observed. Observation of this activity with micro electrodes arrays presents signals containing periodic bursts of activity. The aim of this study is to obtain the same behavior with simulations. Models of excitatory neural networks coupled to models of measures with micro electrode are tested and the parameters are adjusted. It is shown that the level of noise on synaptic transmission triggers a periodic bursting activity of the neural network like the one observed in experimental conditions. Introduction of delays and durations for the synaptic transmission, and adjustments of the parameters enable to obtain different patterns of bursting.