A novel method for classifying cortical state to identify the accompanying changes in cerebral hemodynamics

Slack, Russell; Boorman, Luke; Patel, Pragati; Harris, Sam; Bruyns‐Haylett, Michael; Kennerley, Aneurin J.; Jones, Myles; Berwick, Jason

doi:10.1016/j.jneumeth.2016.04.005

Cited by 2 publications

(2 citation statements)

References 54 publications

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“…Detailed surgical procedures were published in our previous work ( Boorman et al, 2015 , Bruyns-Haylett et al, 2013 , Kennerley et al, 2012 , Slack et al, 2016 ). Female Lister Hooded rats weighing between 200 and 260 g were anaesthetised via intraperitoneal injection of urethane (1.25 g/kg); supplementary doses of 0.1 ml were administered if required.…”

Section: Methodsmentioning

confidence: 99%

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The neurogenesis of P1 and N1: A concurrent EEG/LFP study

et al. 2017

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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).

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Section: Methodsmentioning

confidence: 99%

“…A dental drill was used to thin an area (~1×1 cm 2 ) of the skull overlying the somatosensory cortex to translucency to locate the SIBF using optical imaging. Details of the localisation procedure have been described previously ( Boorman et al, 2015 , Slack et al, 2016 ).…”

Section: Methodsmentioning

confidence: 99%

The neurogenesis of P1 and N1: A concurrent EEG/LFP study

et al. 2017

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Impact of Altered Cholinergic Tones on the Neurovascular Coupling Response to Whisker Stimulation

Lecrux

Sandoe²,

Neupane

et al. 2017

J. Neurosci.

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Brain imaging techniques that use vascular signals to map changes in neuronal activity rely on the coupling between electrophysiology and hemodynamics, a phenomenon referred to as "neurovascular coupling" (NVC). It is unknown whether this relationship remains reliable under altered brain states associated with acetylcholine (ACh) levels, such as attention and arousal and in pathological conditions such as Alzheimer's disease. We therefore assessed the effects of varying ACh tone on whisker-evoked NVC responses in rat barrel cortex, measured by cerebral blood flow (CBF) and neurophysiological recordings (local field potentials, LFPs). We found that acutely enhanced ACh tone significantly potentiated whisker-evoked CBF responses through muscarinic ACh receptors and concurrently facilitated neuronal responses, as illustrated by increases in the amplitude and power in high frequencies of the evoked LFPs. However, the cellular identity of the activated neuronal network within the responsive barrel was unchanged, as characterized by c-Fos upregulation in pyramidal cells and GABA interneurons coexpressing vasoactive intestinal polypeptide. In contrast, chronic ACh deprivation hindered whisker-evoked CBF responses and the amplitude and power in most frequency bands of the evoked LFPs and reduced the rostrocaudal extent and area of the activated barrel without altering its identity. Correlations between LFP power and CBF, used to estimate NVC, were enhanced under high ACh tone and disturbed significantly by ACh depletion. We conclude that ACh is not only a facilitator but also a prerequisite for the full expression of sensory-evoked NVC responses, indicating that ACh may alter the fidelity of hemodynamic signals in assessing changes in evoked neuronal activity.

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A novel method for classifying cortical state to identify the accompanying changes in cerebral hemodynamics

Cited by 2 publications

References 54 publications

The neurogenesis of P1 and N1: A concurrent EEG/LFP study

The neurogenesis of P1 and N1: A concurrent EEG/LFP study

Impact of Altered Cholinergic Tones on the Neurovascular Coupling Response to Whisker Stimulation

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