Virtual Electrode Recording Tool for EXtracellular potentials (VERTEX): comparing multi-electrode recordings from simulated and biological mammalian cortical tissue

Abstract

Local field potentials (LFPs) sampled with extracellular electrodes are frequently used as a measure of population neuronal activity. However, relating such measurements to underlying neuronal behaviour and connectivity is non-trivial. To help study this link, we developed the Virtual Electrode Recording Tool for EXtracellular potentials (VERTEX). We first identified a reduced neuron model that retained the spatial and frequency filtering characteristics of extracellular potentials from neocortical neurons. We then developed VERTEX as an easy-to-use Matlab tool for simulating LFPs from large populations (>100,000 neurons). A VERTEX-based simulation successfully reproduced features of the LFPs from an in vitro multi-electrode array recording of macaque neocortical tissue. Our model, with virtual electrodes placed anywhere in 3D, allows direct comparisons with the in vitro recording setup. We envisage that VERTEX will stimulate experimentalists, clinicians, and computational neuroscientists to use models to understand the mechanisms underlying measured brain dynamics in health and disease.Electronic supplementary materialThe online version of this article (doi:10.1007/s00429-014-0793-x) contains supplementary material, which is available to authorized users.

Active subthreshold dendritic conductances shape the local field potential

“…; Tomsett et al . ). These studies showed, for example, that the lower frequencies of the synaptic input current give the largest contributions to the LFP for two reasons.…”

“…; Tomsett et al . ), recent studies have also been done with neuron models with active dendrites (Schomburg et al . ; Reimann et al .…”

“…Fortunately, the biophysical origin of LFP signals seems well understood in the context of volume conduction theory (Nunez & Srinivasan, 2006), and a forward-modelling scheme linking transmembrane neural currents to recorded electrical potentials, including LFPs, has been established (Rall & Shepherd, 1968;Holt & Koch, 1999). The forward-modelling scheme has been successfully used to study the cortical LFP signal generated by single neurons (Lindén et al 2010) as well as cell populations Lindén et al 2011;Łęski et al 2013;Reimann et al 2013;Tomsett et al 2015). These studies showed, for example, that the lower frequencies of the synaptic input current give the largest contributions to the LFP for two reasons.…”

Computational modeling of neurostimulation in brain diseases

“…In this review, we shall broadly distinguish two levels that are relevant to the characterization of stimulus effects: (i) the neuronal description level, where the (firing and sometimes dendritic) activity of single neurons are modeled; and (ii) the population description level, where the activity of an entire neural population is described, often by population average variables. Figure 1 illustrates examples of these two approaches on simulating a cortical patch of tissue in two recently developed models (Tomsett et al, 2015;Wang et al, 2014). There are several books and reviews on either approach and on the relationship between the two (Coombes, 2006;Deco et al, 2008;Gerstner and Kistler, 2002).…”

“…Numbers on the right indicate cortical depth in micrometers. See Tomsett et al (2015) and www.vertexsimulator.org for details. Bottom: Population-level description, where average excitatory and inhibitory population firing dynamics are simulated.…”