An intra-neural microstimulation system for ultra-high field magnetic resonance imaging and magnetoencephalography

Glover, Paul M.; Watkins, Roger H.; O�Neill, George C.; Ackerley, Rochelle M.; S�nchez-Panchuelo, Rosa-Maria; McGlone, Francis; Brookes, Matthew J.; Wessberg, Johan; Francis, Susan T.

Abstract

Background

Intra-neural microstimulation (INMS) is a technique that allows the precise delivery of low-current electrical pulses into human peripheral nerves. Single unit INMS can be used to stimulate individual afferent nerve fibres during microneurography. Combining this with neuroimaging allows the unique monitoring of central nervous system activation in response to unitary, controlled tactile input, with functional magnetic resonance imaging (fMRI) providing exquisite spatial localisation of brain activity and magnetoencephalography (MEG) high temporal resolution.

New method

INMS systems suitable for use within electrophysiology laboratories have been available for many years. We describe an INMS system specifically designed to provide compatibility with both ultra-high field (7 T) fMRI and MEG. Numerous technical and safety issues are addressed. The system is fully analogue, allowing for arbitrary frequency and amplitude INMS stimulation.

Results

Unitary recordings obtained within both the MRI and MEG screened-room environments are comparable with those obtained in ‘clean’ electrophysiology recording environments. Single unit INMS (current <7 μA, 200 μs pulses) of individual mechanoreceptive afferents produces appropriate and robust responses during fMRI and MEG.
Comparison with existing method(s)

This custom-built MRI- and MEG-compatible stimulator overcomes issues with existing INMS approaches; it allows well-controlled switching between recording and stimulus mode, prevents electrical shocks because of long cable lengths, permits unlimited patterns of stimulation, and provides a system with improved work-flow and participant comfort.

Conclusions

We demonstrate that the requirements for an INMS-integrated system, which can be used with both fMRI and MEG imaging systems, have been fully met.

Citation

Glover, P. M., Watkins, R. H., O’Neill, G. C., Ackerley, R. M., Sánchez-Panchuelo, R.-M., McGlone, F., Brookes, M. J., Wessberg, J., & Francis, S. T. (2017). An intra-neural microstimulation system for ultra-high field magnetic resonance imaging and magnetoencephalography. Journal of Neuroscience Methods, 290, 69-78. https://doi.org/10.1016/j.jneumeth.2017.07.016

• Journal Article Type: Article
• Acceptance Date: Jul 19, 2017
• Online Publication Date: Jul 23, 2017
• Publication Date: Oct 1, 2017
• Deposit Date: Aug 2, 2017
• Publicly Available Date: Aug 2, 2017
• Journal: Journal of Neuroscience Methods
• Print ISSN: 0165-0270
• Electronic ISSN: 1872-678X
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 290
• Pages: 69-78
• DOI: https://doi.org/10.1016/j.jneumeth.2017.07.016
• Keywords: Instrumentation, Stimulus generation, Low-noise amplifier, Nerve stimulation, Magnetoencephalography, Functional magnetic resonance imaging, Ultra-high magnetic field, Human, Microneurography, Tactile, Touch, Low-threshold mechanoreceptor
• Public URL: https://nottingham-repository.worktribe.com/output/885185
• Publisher URL: https://doi.org/10.1016/j.jneumeth.2017.07.016
• Additional Information: This article is maintained by: Elsevier; Article Title: An intra-neural microstimulation system for ultra-high field magnetic resonance imaging and magnetoencephalography; Journal Title: Journal of Neuroscience Methods; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.jneumeth.2017.07.016; Content Type: article; Copyright: © 2017 The Author(s). Published by Elsevier B.V.
• Contract Date: Aug 2, 2017