title: Local field potentials primarily reflect inhibitory neuron activity in human and monkey cortex.
abstract: The local field potential (LFP) is generated by large populations of neurons, but unitary contribution of spiking neurons to LFP is not well characterised. We investigated this contribution in multi-electrode array recordings from human and monkey neocortex by examining the spike-triggered LFP average (st-LFP). The resulting st-LFPs were dominated by broad spatio-temporal components due to ongoing activity, synaptic inputs and recurrent connectivity. To reduce the spatial reach of the st-LFP and observe the local field related to a single spike we applied a spatial filter, whose weights were adapted to the covariance of ongoing LFP. The filtered st-LFPs were limited to the perimeter of 800 μm around the neuron, and propagated at axonal speed, which is consistent with their unitary nature. In addition, we discriminated between putative inhibitory and excitatory neurons and found that the inhibitory st-LFP peaked at shorter latencies, consistently with previous findings in hippocampal slices. Thus, in human and monkey neocortex, the LFP reflects primarily inhibitory neuron activity.
authors.affiliation: Unité de Neurosciences, Information &Complexité, Centre National de la Recherche Scientifique, 91198 Gif-sur-Yvette, France.
authors.forename: Bartosz
authors.initials: B
authors.lastname: Teleńczuk
authors.affiliation: Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, USA.|New England Complex Systems Institute, Cambridge, USA.
authors.forename: Nima
authors.initials: N
authors.lastname: Dehghani
authors.affiliation: L'Institut du Cerveau et de la Moelle Épinière, UMRS 1127, CNRS UMR 7225, Hôpital de la Pitié-Salpêtrière, Paris, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Le Van Quyen
authors.affiliation: Department of Neurology, Massachusetts General Hospital and Harvard Medical School, USA.
authors.forename: Sydney S
authors.initials: SS
authors.lastname: Cash
authors.affiliation: Multimodal Imaging Laboratory, Departments of Neurosciences and Radiology, University of California San Diego, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Halgren
authors.affiliation: Department of Organismal Biology and Anatomy, Committee on Computational Neuroscience, University of Chicago, USA.
authors.forename: Nicholas G
authors.initials: NG
authors.lastname: Hatsopoulos
authors.affiliation: Unité de Neurosciences, Information &Complexité, Centre National de la Recherche Scientifique, 91198 Gif-sur-Yvette, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Destexhe
mesh_terms: D000328:Adult; D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008253:Macaca mulatta; D008875:Middle Aged; D009433:Neural Inhibition; D009474:Neurons / Q000502:physiology*; D062211:Spatio-Temporal Analysis; D055815:Young Adult