Thierry BAL
Research Director
ED 158

In vitro dendritic voltage imaging and biological/artificial hybrid circuits to probe signal processing in dendrites,  synapses and circuits



Thierry BAL
A neuron-machine interface based on dynamic-clamp allows building hybrid circuits, in which living neurons interact in real time with computer models via artificial synapses: 1) We explore the top-...


CNRS Research Director (DR2)

I graduated in 1990 with a PhD in Neurosciences at the University of Bordeaux, on the neurobiology of neuronal networks in invertebrates (the lobster stomatogastric system). I pioneered the technique of neuronal photoinactivation and used it to establish the role of intrinsic membrane properties in central pattern generators.

After a postdoc and associate research scientist positions at the Yale University school of medicine, USA with Pr. D.A. McCormick. I obtained a tenured (CR1) position at the CNRS in 1995, and a research director (DR2) position in 2006. I lead the team "Cybernetics of thalamic and cortical networks" in the UNIC lab, CNRS UPR 3293 in Gif-sur-Yvette (directors Yves Frégnac/Dan shulz).

Scientific productions

We study sensory signal filtering in the thalamus and cortex using advanced in vitro intracellular electrophysiological and neuromimetic techniques (cell-machine interface based on dynamic-clamp). My workgroup has been a major contributor to the study of sleep oscillation genesis in the thalamus (spindle waves). In collaboration with Dr. D.A. McCormick, I have developed a functionally active slice preparation of the ferret visual thalamus that led to a detailed knowledge of cellular and network mechanisms of spindle waves. This early work produced a number of papers published in internationally recognized first-rate journals including Science (1), Neuron and Annual Review of Neuroscience.

Experimental methodology has been pushed forward in the UNIC laboratory, where we have developed new experimental strategies using computer assisted feedback stimulation of thalamic network inputs and hybrid biological-artificial neuromimetic networks (cell-machine interface based on dynamic-clamp) published in Nature (2) and Nature Neuroscience (3). Strong pluridisciplinary interactions with UNIC teams (A. Destexhe, Y. Fregnac), have pushed further the development of cell-machine interface and a novel recording approach based upon active compensation of the electrode (AEC)  allowing high temporal resolution for artificial conductances injection in neurons (4). Our expertise led to the edition of a book on dynamic-clamp with A. Destexhe.

In the recent years we have diversified the application of these techniques in the following issues:

Cellular attentiveness in the thalamus: How synaptic bombardment from the cortex tunes the transfer function of thalamocortical cells. This multidisciplinary work generated several papers (3,5,6) that suggest a mechanism for focal attention implemented at different scales in the thalamus.

Homeostatic plasticity: Identification of the post-synaptic sensors of synaptic activity involved in the retrograde control of neurotransmitter release and the homeostasis of the neuromuscular transmission. It is shown for the first time that a computer-based cell-machine interface can control biological synaptic plasticity in real time (7). 

New techniques

2011-2013: Collaborations at Yale University  on a cellular electrochromic voltage sensitive dye technique with unprecedented temporal resolution (up to 20kHz) to explore voltage transients in dendrites and axons in neurons (8). We are implementing this technique at UNIC. We will test in vitro innovative multiscale approaches that will link the subcellular levels (differentiating dendritic, somatic and axonal compartments of neurons) and the mesoscopic level of small neuronal population, to electrical local field potential (LFP)(9) and local detection of biomagnetic fields with "magnetrodes". In collaboration with A. Destexhe and through external collaborations (CEA-SPEC), we will combine theoretical and experimental analysis to explore these issues.

Academic influence and attractiveness

- Coordination and Participation of national and international collaborative projects (ACI, ANRs, Neuropole de recherche Francilien (NeRF), Fondation pour la recherche médicale, EU-FP7 IST FET BrainScales, Magnetrodes)

- External collaborations: Myriam Pannetier-Lecoeur, Claude Fermon (CEA, Saclay); David McCormick (Yale, USA); Leonel Gomez (Montevideo, Uruguay); José Gomez (Tenerife, Spain); Amanda Casale (San Diego, USA); Amanda Foust (Paris-Descartes, Paris); Nathalie Leresche (UPMC, Paris); Régis Lambert (UPMC, Paris); Gwendal Le Masson (INSERM, Bordeaux); Laurent Venance (College de France, Paris); Mattew Nelson, ICM, Paris)


Teaching and Research training

2008-15: Supervision of 4 PhD, 7 Master students 4 M2; 3 M1 (ENS Paris & Cachan, Supelec, Université Pierre et Marie Curie), and 4 postdocs.

Participation to PhD committees;  Teaching (Supelec, Université Pierre et Marie Curie, Paris 7).


1. vonKrosigk, M., Bal, T. & McCormick, D. Science 261, 361?364 (1993).

2. Le Masson, G., Renaud-Le Masson, S., Debay, D. & Bal, T. Nature 417, 854?858 (2002).

3. Wolfart, J., Debay, D., Le Masson, G., Destexhe, A. & Bal, T. Nat Neurosci 8, 1760?1767 (2005).

4. Brette, R. et al. Neuron 59, 379?391 (2008).

5. Deleuze, C. et al. Journal of Neuroscience 32, 12228?12236 (2012).

6. Behuret et al., (2015) Corticothalamic synaptic noise as a mechanism for selective attention in thalamic neurons. Front Neural Circuits, 9, 11633

7. Ouanounou et al., (2016) A novel synaptic plasticity rule explains homeostasis of neuromuscular transmission. eLife, 5 : e12190

8. Casale et al., (2015) Cortical Interneuron Subtypes Vary in Their Axonal Action Potential Properties. Journal of Neuroscience, 35, 15555–15567

9. Gomes et al. (2016) Intracellular Impedance Measurements Reveal Non-ohmic Properties of the Extracellular Medium around Neurons. Biophysj, 110, 234–246. 







/* Style Definitions */
{mso-style-name:"Tableau Normal";
mso-padding-alt:0cm 5.4pt 0cm 5.4pt;