Our team develops 3 main research axes : 1) plasticity of neuronal excitability, 2) the determinants of neuron synchronization and 3) axonal function.
Functional plasticity in the brain is not only mediated by synapses and voltage-gated ion channels are also regulated by neuronal activity. A great part of our activity is devoted to the characterization of interactions existing between synaptic and intrinsic plasticities. We have established that the learning rules defined for synaptic transmission (BCM, STDP) are also available for the plasticity of dendritic integration in CA1 pyramidal neurons ( Daoudal et al., PNAS 2002 ; Campanac & Debanne, J Physiol 2008 ). We show that h-channel activity is reduced in the dendrites following induction of potentiation of dendritic integration ( Campanac et al., J Neurosci 2008 ).
We study the factors that determine neuronal synchronization at 2 strategic points of the neuron : the synapse and the axon initial segment where the action potential (AP) is generated. We have recently established that the synaptic delay is not constant but depends on release probability that varies during several forms of short- and long-term synaptic plasticity ( Boudkkazi et al., Neuron 2007 ). We have also demonstrated the importance of voltage trajectories preceding the spike in determining temporal precision of neuronal firing ( Sourdet et al. J Neurosci. 2003 ; Cudmore et al., in revision). We also explore the role of inhibitory synaptic activity in the precision of neuronal discharge (Caillard, in preparation). Finally, our current works examine how voltage-gated ion channels determine information processing in small circuits ( Kopysova & Debanne, J. Neurosci 1998 ; Debanne, Nat Rev Neurosci 2004 ). For this purpose, we have recently developed whole-cell patch-clamp recordings from axons.
Team :
5 researchers (neurophysiologists and cellular biologists), 1 engineer, 1 technician, 1 post-doc and 3 PhD students
Tools and methodology :
Beside cellular biology equipments such as the gene transfert set-up, 5 patch-clamp set-ups are available in the team allowing multiple recordings (soma-soma, soma-dendrite ou soma-axon) on acute slice or organotypic slice cultures. Some of these set-ups allow specific tasks such as simulation of voltage-gated conductance with a dynamic-clamp amplifier, building hybrid network, imaging intracellular calcium in neurons or membrane potential with a confocal microscope. .
Softwares :
Detectivent is Software developped by Norbert Ankri. It allows detection and analysis of synaptic events.
Grants :
Our team is supported by grants from the following organisms and foundations
Main Publications :
Pre & postsynaptic tuning of action potential timing by spontaneous GABAergic activity.
Caillard O.
PLoS One.
2011 ; 6(7):e22322
The role of hyperpolarization-activated cationic current in spike-time precision and intrinsic resonance in cortical neurons in vitro.
Gastrein P, Campanac E, Gasselin C, Cudmore RH, Bialowas A, Carlier E, Fronzaroli-Molinieres L, Ankri N, Debanne D.
J Physiol.
2011 : 589,3753-73.
Axon physiology.
Debanne D, Campanac E, Bialowas A, Carlier E, Alcaraz G.
Physiol Rev.
2011 : 91, 555-602.
Presynaptic action potential waveform determines cortical synaptic latency.
Boudkkazi S, Fronzaroli-Molinieres L, Debanne D.
J Physiol.
2011 : 589, 1117-31.
Spike-time precision and network synchrony are controlled by the homeostatic regulation of the D-type potassium current.
Cudmore RH, Fronzaroli-Molinieres L, Giraud P, Debanne D.
J. Neurosci.
2010 : 30, 2885-95
Paired-recordings from synaptically coupled cortical and hippocampal neurons in acute and cultured brain slices
Debanne D, Boudkkazi S., Campanac E., Cudmore R.H., Giraud P., Fronzaroli-Molinieres L., Carlier E. and Caillard O.
Nature Protocols.
2008 : 3,1559-68
Downregulation of dendritic Ih in CA1 pyramidal neurons after LTP
Campanac E., Daoudal G., Ankri N. and Debanne D.
Journal of Neuroscience.
2008 : 23, 8635-43
Spike timing-dependent plasticity : a learning rule for dendritic integration in rat CA1 pyramidal neurons
Campanac E. and Debanne D.
Journal of Physiology (London).
2008 : 586, 779-793
Release-dependent variations in synaptic latency : a putative code for short- and long-term synaptic dynamics
Boudkkazi S., Carlier E., Ankri N., Caillard O., Giraud P., Fronzaroli-Molinieres L. and Debanne D.
Neuron. 2007 : 56 ,1048-60
Metabotropic glutamate receptor subtype 1 regulate sodium currents in rat neocortical pyramidal neurons
Carlier E., Sourdet V., Boudkkazi S., Déglise P., Ankri N., Fronzaroli-Molinieres L. and Debanne D.
Journal of Physiology (London).
2006 : 577, 141-154
Information processing in the axon
Debanne, D.
Nature Review Neuroscience. 2004 : 5, 304 - 16
Long-term enhancement of neuronal excitability and temporal fidelity mediated by metabotropic glutamate receptor subtype 5
Sourdet, V., Russier, M., Daoudal, G., Ankri, N. and Debanne, D.
Journal of Neuroscience.
2003 : 23, 10238 - 48
Bidirectional plasticity of excitatory postsynaptic potential (EPSP)-spike coupling in CA1 hippocampal pyramidal neurons
Daoudal, G., Hanada, Y., and Debanne, D.
Proc.Natl.Acad.Sci.U.S.A. 2002 : 99, 14512 - 17
GABA and glycine co-release optimizes functional inhibition in rat brainstem motoneurons in vitro
Russier, M., Kopysova, I. L., Ankri, N., Ferrand, N., and Debanne, D.
Journal of Physiology (London).
2002 : 541, 123 - 37
Critical role of axonal A-type K+ channels and axonal geometry in the gating of action potential propagation along CA3 pyramidal cell axons : a simulation study
Kopysova, I. L. and Debanne, D.
Journal of Neuroscience.
1998 : 18, 7436 - 51
