Oct 21, 2020
Electrophysiological recording of electrically-evoked compound action potentials
- 1Bionics Institute
- SPARCTech. support email: info@neuinfo.org
Protocol Citation: James B Fallon, Sophie Payne 2020. Electrophysiological recording of electrically-evoked compound action potentials. protocols.io https://dx.doi.org/10.17504/protocols.io.bfwyjpfw
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
Created: May 04, 2020
Last Modified: November 27, 2023
Protocol Integer ID: 36536
Keywords: Electrophysiology, Electrical stimulation, Neural recordings
Abstract
Recording electrically-evoked compound action potentials (ECAPs) is performed to confirm that the electrode array is appropriately placed along the nerve. Recording ECAPS also allows confirmation that electrical stimulation is above neural threshold i.e. that electrical stimulation activates neural activity. The procedure is performed under anesthesia (immediately post-surgery) or in awake animals, and the procedure should incorporate all local requirements for standards of animal experimentation.
Materials
MATERIALS
StimulatorBionics Institute
Isolated Differential Amplifier with active probeWorld Precision InstrumentsCatalog #ISO-80
National Instruments data acquisition deviceNational InstrumentsCatalog #USB-6210
Igor Pro-8Wavemetrics, IncCatalog #8.04
Electrophysiological testing
Electrophysiological testing
This procedure is performed immediately following implantation surgery or in awake, unrestrained animals. The electrical impedance of the array are tested using a custom stimulation to assess any open or short circuiting of wires.
CITATION
Measure the impedance of each electrode using biphasic current pulses passed between the electrode of interest and all other implanted electrodes. Measure the peak voltage at the end of the first phase (Vtotal) of the current pulse following delivery of a 25 ms per phase current pulse and current of 931 mA.
If all electrodes are functional, connect a pair of electrodes to the stimulator and a pair of electrodes to the electrophysiological recording equipment
Record ECAPs similar to that described in:
CITATION
Generate electrically-evoked compound action potentials (ECAPs) using bipolar stimulation and recording electrode configuration.
Make two sets of evoked electrophysiological recordings (averaged from a total of 50 responses).
Make recordings at currents from 0 to 2 mA in 0.1 mA steps using a biphasic pulse (width = 200 ms, 50 ms interphase gap) presented at a rate of 10 pulses per second.
Sample recordings at a rate of 100 kHz and filter (high pass: 200 Hz; low pass: 2000 Hz; voltage gain 103)
The electrically-evoked neural response threshold was defined as the minimum stimulus intensity producing a response amplitude of at least 0.1 mV
Citations
Step 1
Senn, P., R. K. Shepherd, and J. B. Fallon. Focused electrical stimulation using a single current source
10.1088/1741-2552/aad0aStep 3
Sophie C. Payne, John B. Furness, Owen Burns, Alicia Sedo, Tomoko Hyakumura, Robert K. Shepherd, James B. Fallon. Anti-inflammatory Effects of Abdominal Vagus Nerve Stimulation on Experimental Intestinal Inflammation
10.3389/fnins.2019.00418