title: Correlates of a single cortical action potential in the epidural EEG.
abstract: To identify the correlates of a single cortical action potential in surface EEG, we recorded simultaneously epidural EEG and single-unit activity in the primary somatosensory cortex of awake macaque monkeys. By averaging over EEG segments coincident with more than hundred thousand single spikes, we found short-lived (≈ 0.5 ms) triphasic EEG deflections dominated by high-frequency components >800 Hz. The peak-to-peak amplitude of the grand-averaged spike correlate was 80 nV, which matched theoretical predictions, while single-neuron amplitudes ranged from 12 to 966 nV. Combining these estimates with post-stimulus-time histograms of single-unit responses to median-nerve stimulation allowed us to predict the shape of the evoked epidural EEG response and to estimate the number of contributing neurons. These findings establish spiking activity of cortical neurons as a primary building block of high-frequency epidural EEG, which thus can serve as a quantitative macroscopic marker of neuronal spikes.
authors.affiliation: Unité de Neurosciences, Information et Complexité, Centre National de la Recherche Scientifique, 91198 Gif-sur-Yvette, France; Neurophysics Group, Department of Neurology, Campus Benjamin Franklin, Charité-Universitätsmedizin Berlin, 12200 Berlin, Germany; Department of Biology, Institute for Theoretical Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany. Electronic address: b.telenczuk@biologie.hu-berlin.de.
authors.forename: Bartosz
authors.initials: B
authors.lastname: Teleńczuk
authors.affiliation: Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Stuart N
authors.initials: SN
authors.lastname: Baker
authors.affiliation: Department of Biology, Institute for Theoretical Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany.
authors.forename: Richard
authors.initials: R
authors.lastname: Kempter
authors.affiliation: Neurophysics Group, Department of Neurology, Campus Benjamin Franklin, Charité-Universitätsmedizin Berlin, 12200 Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany; Bernstein Focus Neurotechnology Berlin, 10587 Berlin, Germany.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Curio
mesh_terms: D000200:Action Potentials; D000818:Animals; D058256:Brain Waves / Q000502:physiology*; D004388:Dura Mater; D004569:Electroencephalography / Q000379:methods*; D008253:Macaca mulatta; D009474:Neurons / Q000502:physiology*; D013003:Somatosensory Cortex / Q000502:physiology*
keywords: EEG; Single-unit activity; Somatosensory cortex; Spike-triggered average