Dynamic I-V Curves Are Reliable Predictors of Naturalistic Pyramidal-Neuron Voltage Traces

• Published in: Journal of neurophysiology Vol. 99; no. 2; pp. 656 - 666
• Main Authors: Badel, Laurent, Lefort, Sandrine, Brette, Romain, Petersen, Carl C. H, Gerstner, Wulfram, Richardson, Magnus J. E
• Format: Journal Article
• Language: English
• Published: United States Am Phys Soc 01-02-2008; American Physiological Society
• Subjects: Animals; Animals, Newborn; Bioinformatics; Cerebral Cortex - cytology; Computer Science; Differential Threshold; Dose-Response Relationship, Radiation; Electric Stimulation; Electricity; In Vitro Techniques; Life Sciences; Membrane Potentials - physiology; Membrane Potentials - radiation effects; Mice; Mice, Inbred C57BL; Models, Neurological; Nonlinear Dynamics; Patch-Clamp Techniques - methods; Pyramidal Cells - physiology; Pyramidal Cells - radiation effects; Quantitative Methods
• ISSN: 0022-3077; 1522-1598
• DOI: 10.1152/jn.01107.2007

1 Laboratory of Computational Neuroscience, School of Computer and Communication Sciences and Brain Mind Institute and 2 Laboratory of Sensory Processing, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland; 3 Équipe Odyssée, Département d'Informatique, École Normale Supérieure, Paris, France; and 4 Warwick Systems Biology Centre, University of Warwick, Coventry, United Kingdom
Submitted 5 October 2007;
accepted in final form 3 December 2007
Neuronal response properties are typically probed by intracellular measurements of current-voltage ( I-V ) relationships during application of current or voltage steps. Here we demonstrate the measurement of a novel I-V curve measured while the neuron exhibits a fluctuating voltage and emits spikes. This dynamic I-V curve requires only a few tens of seconds of experimental time and so lends itself readily to the rapid classification of cell type, quantification of heterogeneities in cell populations, and generation of reduced analytical models. We apply this technique to layer-5 pyramidal cells and show that their dynamic I-V curve comprises linear and exponential components, providing experimental evidence for a recently proposed theoretical model. The approach also allows us to determine the change of neuronal response properties after a spike, millisecond by millisecond, so that postspike refractoriness of pyramidal cells can be quantified. Observations of I-V curves during and in absence of refractoriness are cast into a model that is used to predict both the subthreshold response and spiking activity of the neuron to novel stimuli. The predictions of the resulting model are in excellent agreement with experimental data and close to the intrinsic neuronal reproducibility to repeated stimuli.
Address for reprint requests and other correspondence: M.J.E. Richardson, Warwick Systems Biology Centre, University of Warwick, CV4 7AL, Coventry, UK (E-mail: magnus.richardson{at}warwick.ac.uk )