Nicolas Doyon, Ph.D.
Associate professor, researcher
Reaching a deeper understanding of neurons and neural networks through mathematical simulation and modeling.
Professor Nicolas Doyon, from the Department of Mathematics and Statistics, uses his expertise in mathematical modeling to better understand how ion transporters influence signal processing by neurons. Precise control of the amounts of certain ions, such as chloride ions, is necessary for the proper functioning of neurons. Professor Doyon's studies have led to a better understanding of the spatio-temporal control of ion transport in neurons.
Defects in the regulation of chloride ion transport are associated with several diseases such as chronic pain, epilepsy, autism and schizophrenia, and the restoration of control is therefore an attractive therapeutic target for these diseases. A specific protein, named KCC2, has the important role of removing chloride ions and thus controlling their level in cells. By modeling KCC2 function under different conditions, Dr. Doyon's research has shown that subtle variations in time and space of KCC2 activity can have important effects on neuron function. These studies may lead to better control strategies for KCC2, which would have significant therapeutic benefits.
I use mathematical modeling and numerical simulation in order to better understand neurons and neural networks. My specific research interest include:
-Modeling the dynamical evolution of intracellular chloride concentration and its impact on synaptic signaling, the quality of information processing and the energy consumption of neurons. I apply models describing these fluctuations especially in the context of the disregulation of chloride homeostasis resulting from the downregulation of the KCC2 cotransporter occuring in neuropathic pain.
-Using the Finite Element Method to solve the Poisson-Nernst-Planck equations. These equations allow to describe with high accuracy and spatial resolution the dynamical evolution of ionic concentrations and electrical potential in neural structures with complex geometries such as the dendritic spines and nodes of Ranvier.
-Modelling optogentic experiments and the recording of extracellular electric field. In collaboration with research from the Doric Lenses enterprise, we develop a simulation software allowing to predict the impact of properties and positions of electrodes and optical fibers and the quality of recordings.
-Studying complex network and the impact of network topology on signal processing.
Frank Boahen, Master degree student. Application of the Finite Elements Method the describe electrodiffusion in dendritic spines.
Nadège Octavie Lenkeu Lenkeu, Master degree student, modelling cell swelling during osmotic shocks.
Tahmineh Azizi, Ph D. student, dynamical systems and fluctuation of ionic concentrations.
Maurice-Étienne Cloutier, Ph D. student. Analytic number theory.
François Laniel, Ph D. student. Analytic number theory.
Vincent Ouellet, Ph D. student. Analytic number theory.
1) Automatic mesh adaptation improves simulation of electrodiffusion in the node of Ranvier, 2016, Ibrahima Dione, Jean Deteix, Thomas Briffard, Éric Chamberland, Nicolas Doyon, PLOS ONE accepted for publication.
2) Chloride regulation: a dynamic equilibrium crucial for synaptic inhibition, 2016,
Nicolas Doyon, Laurent Vinay, Steve A Prescott, Yves De Koninck, NEURON 89 (6), 1157-1172.
3) Counting Hidden Neural Network, 2016, Anathony Richard, Patrick Desrosiers, Simon Hardy, Nicolas Doyon, JOURNAL OF INTEGERS SEQUENCES 19 (2), 3.
4) Mild KCC2 hypofunction causes inconspicuous chloride dysregulation that degrades neural coding, 2015, Nicolas Doyon, Steve A Prescott, Y De Koninck, 2015. Frontiers in cellular neuroscience 9.
5) Allosteric modulation of metabotropic glutamate receptors by chloride ions,
Amélie S Tora, Xavier Rovira, Ibrahima Dione, Hugues-Olivier Bertrand, Isabelle Brabet, Yves De Koninck, Nicolas Doyon, Jean-Philippe Pin, Francine Acher, Cyril Goudet, 2015. The FASEB Journal, 29, 10 4174-4188.
6) Morphine hyperalgesia gated through microglia-mediated disruption of neuronal Cl-homeostasis. Francesco Ferrini, Tuan Trang, Theresa-Alexandra M Mattioli, Sophie Laffray, Thomas Del'Guidice, Louis-Etienne Lorenzo, Annie Castonguay, Nicolas Doyon, Wenbo Zhang, Antoine G Godin, Daniela Mohr, Simon Beggs, Karen Vandal, Jean-Martin Beaulieu, Catherine M Cahill, Michael W Salter, Yves De Koninck, 2013. NATURE NEUROSCIENCE, 1,62 183-192.
7) Efficacy of synaptic inhibition depends on multiple, dynamically interacting mechanisms implicated in chloride homeostasis. Nicolas Doyon, Steve A Prescott, Annie Castonguay, Antoine G Godin, Helmut Kröger, Yves De Koninck, 2011. PLoS Comput Biol. 7-9.
8) Inhibitory synaptic plasticity: spike timing-dependence and putative network function. Tim P Vogels, Robert C Froemke, Nicolas Doyon, Matthieu Gilson, Julie S Haas, Robert Liu, Arianna Maffei, Paul Miller, Corette Wierenga, Melanie A Woodin, Friedemann Zenke, Henning Sprekeler, 2013. FRONTIERS IN NEURAL CIRCUTIS, volume 7, 119 pages.
9) Treating pathological pain: is KCC2 the key to the gate? Nicolas Doyon, Francesco Ferrini, Martin Gagnon, Yves De Koninck. 2013. EXPERT REVIEW ON NEUROPATHICS. Vol 13, 5. pages
469-471.
10) On the counting function for the Niven numbers, Jean-Marie De Koninck, Nicolas Doyon, Imre Katai, 2003, ACTA ARITMETICA, Vol. 106 Pages 265-275.
I obtained a bachelor degree from Laval University during which I developed a passion for scientific investigation. I then pursued a Mater Degree in Applied Mathematics at the University of Montreal during which I used mathematical tools to create models of electrical propagation in cardiac valves.
After completing a Ph.D. in theoretical mathematics during which I performed research in analytic number theory, I started a postdoctoral internship at the University Institute in Mental Health of Quebec City. Since then, I work in collaboration with many experimental investigators to develop mathematical models which help better understand how the brain works. I became a professor at the department of mathematics and statistics of Laval University in 2013.
Star Teacher, 2016. Awarded by the Faculty of Engineering and Sciences for the quality of teaching.
Star Teacher, 2016. Awarded by the Faculty of Engineering and Sciences for the quality of teaching.
Individual NSERC grant, 35K$/year for 5 years. 2014-2019.
Grant for the establishment of new researcher of the FQRNT, 20K$/year for 2 years. 2013-2015.
Team grant of the FQRNT, co-investigator. Individual potion 15K$/year for 3 years 2014-2017.
ENGAGE grant from NSERC. 25K$ for 6 mois. 2016
2601 Chemin de la Canardière
Québec (Québec)
G1J 2G3
Canada
