title: The neurogenesis of P1 and N1: A concurrent EEG/LFP study.
abstract: It is generally recognised that event related potentials (ERPs) of electroencephalogram (EEG) primarily reflect summed post-synaptic activity of the local pyramidal neural population(s). However, it is still not understood how the positive and negative deflections (e.g. P1, N1 etc) observed in ERP recordings are related to the underlying excitatory and inhibitory post-synaptic activity. We investigated the neurogenesis of P1 and N1 in ERPs by pharmacologically manipulating inhibitory post-synaptic activity in the somatosensory cortex of rodent, and concurrently recording EEG and local field potentials (LFPs). We found that the P1 wave in the ERP and LFP of the supragranular layers is determined solely by the excitatory post-synaptic activity of the local pyramidal neural population, as is the initial segment of the N1 wave across cortical depth. The later part of the N1 wave was modulated by inhibitory post-synaptic activity, with its peak and the pulse width increasing as inhibition was reduced. These findings suggest that the temporal delay of inhibition with respect to excitation observed in intracellular recordings is also reflected in extracellular field potentials (FPs), resulting in a temporal window during which only excitatory post-synaptic activity and leak channel activity are recorded in the ERP and evoked LFP time series. Based on these findings, we provide clarification on the interpretation of P1 and N1 in terms of the excitatory and inhibitory post-synaptic activities of the local pyramidal neural population(s).
authors.affiliation: School of Systems Engineering, Whiteknights, University of Reading, Reading RG6 7AY, United Kingdom. Electronic address: m.bruyns-haylett@reading.ac.uk.
authors.forename: Michael
authors.initials: M
authors.lastname: Bruyns-Haylett
authors.affiliation: School of Systems Engineering, Whiteknights, University of Reading, Reading RG6 7AY, United Kingdom. Electronic address: Jingjing.luo@reading.ac.uk.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Luo
authors.affiliation: Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom.
authors.forename: Aneurin J
authors.initials: AJ
authors.lastname: Kennerley
authors.affiliation: Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom.
authors.forename: Sam
authors.initials: S
authors.lastname: Harris
authors.affiliation: Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom.
authors.forename: Luke
authors.initials: L
authors.lastname: Boorman
authors.affiliation: Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Milne
authors.affiliation: Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Vautrelle
authors.affiliation: School of Systems Engineering, Whiteknights, University of Reading, Reading RG6 7AY, United Kingdom.
authors.forename: Yurie
authors.initials: Y
authors.lastname: Hayashi
authors.affiliation: School of Systems Engineering, Whiteknights, University of Reading, Reading RG6 7AY, United Kingdom.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Whalley
authors.affiliation: Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom.
authors.forename: Myles
authors.initials: M
authors.lastname: Jones
authors.affiliation: Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom.
authors.forename: Jason
authors.initials: J
authors.lastname: Berwick
authors.affiliation: Department of Biomedical Engineering, Florida International University, Miami, FL 33174, United States of America.
authors.forename: Jorge
authors.initials: J
authors.lastname: Riera
authors.affiliation: School of Systems Engineering, Whiteknights, University of Reading, Reading RG6 7AY, United Kingdom. Electronic address: ying.zheng@reading.ac.uk.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zheng
mesh_terms: D000818:Animals; D058256:Brain Waves; D004569:Electroencephalography; D005073:Evoked Potentials, Somatosensory; D005260:Female; D009433:Neural Inhibition; D010812:Physical Stimulation; D051381:Rats; D013003:Somatosensory Cortex / Q000502:physiology*; D055698:Touch Perception / Q000502:physiology
keywords: Local field potentials (LFPs); N1; P1; bicuculline; electroencephalogram (EEG); event related potentials (ERPs); excitation; inhibition; rat; somatosensory cortex; somatosensory evoked potentials (SEP); whisker barrel cortex