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Accueil du site > Séminaires > Soutenances 2021 > PhD Defense : Mallory Dazza ; Thursday July 22th 2021, 2 pm, "Activity and morphology of neuronal cultures A study on spatio-temporal patterns of activity in neuronal networks and neurons morphology in 2D cultures".

PhD Defense : Mallory Dazza ; Thursday July 22th 2021, 2 pm, "Activity and morphology of neuronal cultures A study on spatio-temporal patterns of activity in neuronal networks and neurons morphology in 2D cultures"

Sauf mention contraire, les séminaires et les soutenances se déroulent à 11h30 en salle 454A du bâtiment Condorcet.


Thèse de Mallory Dazza effectuée sous la direction de Samuel Bottani (MSC) et de Catherine Villard (Institut Curie).

Soutenance le jeudi 22 juillet 2022 à 14h00.

Lieu : 45 rue des Saints-Pères, salle R229 (second étage) et diffusion sur zoom.

Activity and morphology of neuronal cultures

Abstract : A study on spatio-temporal patterns of activity in neuronal networks and neurons morphology in 2D cultures

The goal of my thesis is to understand the relationship between neuronal network structures and spatio-temporal dynamics of neurons’ activity, either recorded in vitro, or simulated with mathematical models. My work focuses on neuronal cultures, as these experimental set-ups are increasingly studied in technical applications, but lack detailed theoretical characterisation and understanding.

The theoretical modeling involves two levels of interests : the activity and the establishment of connections in neuronal cultures. I was interested in two different models of activity : the static quorum percolation model and the dynamical adaptive exponential integrate and fire. Network connectome of neuronal culture is taken into account with a network embedded in the two-dimensional space. I investigate the phase transition of the Quorum Percolation Model and identify a transition between 2 types of propagating dynamics. With a phase specifically designed to investigate neuronal activity, I propose a novel method to analyse and identify the periodic bursting regime both in time and space. This analysis reveals specific characteristics of bursting initiation that help us in the understanding of the fundamental principles that relate the spatial network and the collective neuronal activity.

The second part of my thesis is experimental : the goal is to investigate and quantify neurons morphology in 2D cultures. Indeed, although many studies indicate that spatial correlations are a key parameter to understand the propagating bursting dynamics in culture, the underlying network structure is poorly characterized. The challenge is to observe a single cell in a culture dense biological medium. With viral infection, controlled in its quantity, we were able to observe individual cells, expressing the green fluorescent protein, in a complex biological environment. The confocal images are automatically processed with a python program able to extract and quantify neuritis morphology. Such measurements will be of great help in order to refine theoretical network models, and for future microfluidic devices that aim at controlling the network structure. I identify two regimes in the correlation of neurite path showing the interaction between neurite stiffness and adhesion to its environment and estimate the average connection length in a biological network with a simple toy model.


Contact : Équipe séminaires / Seminar team - Published on / Publié le 20 juillet