title: Parameter extraction and classification of three cortical neuron types reveals two distinct adaptation mechanisms.
abstract: Cortical information processing originates from the exchange of action potentials between many cell types. To capture the essence of these interactions, it is of critical importance to build mathematical models that reflect the characteristic features of spike generation in individual neurons. We propose a framework to automatically extract such features from current-clamp experiments, in particular the passive properties of a neuron (i.e., membrane time constant, reversal potential, and capacitance), the spike-triggered adaptation currents, as well as the dynamics of the action potential threshold. The stochastic model that results from our maximum likelihood approach accurately predicts the spike times, the subthreshold voltage, the firing patterns, and the type of frequency-current curve. Extracting the model parameters for three cortical cell types revealed that cell types show highly significant differences in the time course of the spike-triggered currents and moving threshold, that is, in their adaptation and refractory properties but not in their passive properties. In particular, GABAergic fast-spiking neurons mediate weak adaptation through spike-triggered currents only, whereas regular spiking excitatory neurons mediate adaptation with both moving threshold and spike-triggered currents. GABAergic nonfast-spiking neurons combine the two distinct adaptation mechanisms with reduced strength. Differences between cell types are large enough to enable automatic classification of neurons into three different classes. Parameter extraction is performed for individual neurons so that we find not only the mean parameter values for each neuron type but also the spread of parameters within a group of neurons, which will be useful for future large-scale computer simulations.
authors.affiliation: School of Computer and Communication Sciences and School of Life Sciences, Ecole Polytechnique Federale de Lausanne, 1015 Lausanne EPFL, Switzerland. skander.mensi@epfl.ch
authors.forename: Skander
authors.initials: S
authors.lastname: Mensi
authors.forename: Richard
authors.initials: R
authors.lastname: Naud
authors.forename: Christian
authors.initials: C
authors.lastname: Pozzorini
authors.forename: Michael
authors.initials: M
authors.lastname: Avermann
authors.forename: Carl C H
authors.initials: CC
authors.lastname: Petersen
authors.forename: Wulfram
authors.initials: W
authors.lastname: Gerstner
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000222:Adaptation, Physiological / Q000502:physiology; D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D008564:Membrane Potentials / Q000502:physiology; D051379:Mice; D008959:Models, Neurological; D009474:Neurons / Q000502:physiology*; D018408:Patch-Clamp Techniques / Q000379:methods*