title: High Stimulus-Related Information in Barrel Cortex Inhibitory Interneurons.
abstract: The manner in which populations of inhibitory (INH) and excitatory (EXC) neocortical neurons collectively encode stimulus-related information is a fundamental, yet still unresolved question. Here we address this question by simultaneously recording with large-scale multi-electrode arrays (of up to 128 channels) the activity of cell ensembles (of up to 74 neurons) distributed along all layers of 3-4 neighboring cortical columns in the anesthetized adult rat somatosensory barrel cortex in vivo. Using two different whisker stimulus modalities (location and frequency) we show that individual INH neurons--classified as such according to their distinct extracellular spike waveforms--discriminate better between restricted sets of stimuli (≤6 stimulus classes) than EXC neurons in granular and infra-granular layers. We also demonstrate that ensembles of INH cells jointly provide as much information about such stimuli as comparable ensembles containing the ~20% most informative EXC neurons, however presenting less information redundancy - a result which was consistent when applying both theoretical information measurements and linear discriminant analysis classifiers. These results suggest that a consortium of INH neurons dominates the information conveyed to the neocortical network, thereby efficiently processing incoming sensory activity. This conclusion extends our view on the role of the inhibitory system to orchestrate cortical activity.
authors.affiliation: Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.
authors.forename: Vicente
authors.initials: V
authors.lastname: Reyes-Puerta
authors.affiliation: Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.
authors.forename: Suam
authors.initials: S
authors.lastname: Kim
authors.affiliation: Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.
authors.forename: Jyh-Jang
authors.initials: JJ
authors.lastname: Sun
authors.affiliation: Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.
authors.forename: Barbara
authors.initials: B
authors.lastname: Imbrosci
authors.affiliation: Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.
authors.forename: Werner
authors.initials: W
authors.lastname: Kilb
authors.affiliation: Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.
authors.forename: Heiko J
authors.initials: HJ
authors.lastname: Luhmann
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D019295:Computational Biology; D007395:Interneurons / Q000502:physiology*; D008297:Male; D008959:Models, Neurological; D009415:Nerve Net / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D013003:Somatosensory Cortex / Q000502:physiology*