UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Does Impedance Matter When Recording Spikes With Polytrodes

Neto, JP; Baiao, P; Lopes, G; Frazao, J; Nogueira, J; Fortunato, E; Barquinha, P; (2018) Does Impedance Matter When Recording Spikes With Polytrodes. Frontiers in Neuroscience , 12 , Article 715. 10.3389/fnins.2018.00715. Green open access

[thumbnail of Neto_fnins-12-00715.pdf]
Preview
Text
Neto_fnins-12-00715.pdf - Published Version

Download (2MB) | Preview

Abstract

Extracellular microelectrodes have been widely used to measure brain activity, yet there are still basic questions about the requirements for a good extracellular microelectrode. One common source of confusion is how much an electrode’s impedance affects the amplitude of extracellular spikes and background noise. Here we quantify the effect of an electrode’s impedance on data quality in extracellular recordings, which is crucial for both the detection of spikes and their assignment to the correct neurons. This study employs commercial polytrodes containing 32 electrodes (177 μm2) arranged in a dense array. This allowed us to directly compare, side-by-side, the same extracellular signals measured by modified low impedance (∼100 kΩ) microelectrodes with unmodified high impedance (∼1 MΩ) microelectrodes. We begin with an evaluation of existing protocols to lower the impedance of the electrodes. The poly (3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT-PSS) electrodeposition protocol is a simple, stable, and reliable method for decreasing the impedance of a microelectrode up to 10-fold. We next record in vivo using polytrodes that are modified in a ‘chess board’ pattern, such that the signal of one neuron is detected by multiple coated and non-coated electrodes. The performance of the coated and non-coated electrodes is then compared on measures of background noise and amplitude of the detected action potentials. If the proper recording system is used, then the impedance of a microelectrode within the range of standard polytrodes (∼0.1 to 2 MΩ) does not greatly affect data quality and spike sorting. This study should encourage neuroscientists to stop worrying about one more unknown.

Type: Article
Title: Does Impedance Matter When Recording Spikes With Polytrodes
Open access status: An open access version is available from UCL Discovery
DOI: 10.3389/fnins.2018.00715
Publisher version: https://doi.org/10.3389/fnins.2018.00715
Language: English
Additional information: This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Keywords: microelectrodes, impedance, spikes, noise, coating
UCL classification: UCL
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > The Sainsbury Wellcome Centre
URI: https://discovery.ucl.ac.uk/id/eprint/10061489
Downloads since deposit
69Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item