Computing extracellular electric potentials from neuronal simulations

TL;DR

This paper explains how volume conductor theory, used to compute extracellular neural signals, can be derived from detailed electrodiffusive models, and demonstrates its application to various neural measurements.

Contribution

It derives volume conductor theory from electrodiffusive models and illustrates its application to neural signals like spikes, LFP, and EEG.

Findings

VC theory can be derived from electrodiffusive models

Examples of computing neural signals from theory

Clarification of assumptions in VC theory

Abstract

Measurements of electric potentials from neural activity have played a key role in neuroscience for almost a century, and simulations of neural activity is an important tool for understanding such measurements. Volume conductor (VC) theory is used to compute extracellular electric potentials such as extracellular spikes, MUA, LFP, ECoG and EEG surrounding neurons, and also inversely, to reconstruct neuronal current source distributions from recorded potentials through current source density methods. In this book chapter, we show how VC theory can be derived from a detailed electrodiffusive theory for ion concentration dynamics in the extracellular medium, and show what assumptions that must be introduced to get the VC theory on the simplified form that is commonly used by neuroscientists. Furthermore, we provide examples of how the theory is applied to compute spikes, LFP signals and EEG signals generated by neurons and neuronal populations.