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Physiological Processes Underlying Short Interval Intracortical Facilitation in the Human Motor Cortex

Short interval intracortical facilitation (SICF) may be elicited by a paired pulse transcranial magnetic stimulation (TMS) paradigm, whereby a suprathreshold first stimulus (S1) precedes a perithreshold second stimulus (S2). Other facilitatory circuits can be probed by TMS such as intracranial facil...

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Autores principales: Van den Bos, Mehdi A. J., Menon, Parvathi, Howells, James, Geevasinga, Nimeshan, Kiernan, Matthew C., Vucic, Steve
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5904283/
https://www.ncbi.nlm.nih.gov/pubmed/29695952
http://dx.doi.org/10.3389/fnins.2018.00240
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author Van den Bos, Mehdi A. J.
Menon, Parvathi
Howells, James
Geevasinga, Nimeshan
Kiernan, Matthew C.
Vucic, Steve
author_facet Van den Bos, Mehdi A. J.
Menon, Parvathi
Howells, James
Geevasinga, Nimeshan
Kiernan, Matthew C.
Vucic, Steve
author_sort Van den Bos, Mehdi A. J.
collection PubMed
description Short interval intracortical facilitation (SICF) may be elicited by a paired pulse transcranial magnetic stimulation (TMS) paradigm, whereby a suprathreshold first stimulus (S1) precedes a perithreshold second stimulus (S2). Other facilitatory circuits can be probed by TMS such as intracranial facilitation, however the cortical contributions to these circuits may lie partially outside of M1. SICF as such represents a unique analog to M1 inhibitory circuits such as short interveal intracortical circuits. The aim of the present study was to provide insight into the physiological processes underlying the development of SICF using the threshold tracking TMS technique which was recently demonstrated to have significant reliability. TMS studies were undertaken on 35 healthy controls, using either a 90 mm circular and 70 mm figure of eight coil, and one of two targets (0.2 and 1.0 mV) tracked. The motor evoked potential (MEP) responses were recorded from the abductor pollicis brevis. SICF was consistently evident between interstimulus intervals (ISI) of 1–5 ms (P < 0.001), with two peaks occurring ISIs 1.5 and 3 ms when using the circular coil. A significant SICF reduction (F = 5.631, P < 0.05) was evident with the higher tracking target, while SICF increased when stimulating with the figure of eight coil. While there was a correlation between SICF and CSP duration, there was no relationship between SICF and SICI or ICF. Age appeared to have no influence on SICF, SICI, or ICF. Findings from the present work suggest that SICF appears to be mediated by I-wave facilitation.
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spelling pubmed-59042832018-04-25 Physiological Processes Underlying Short Interval Intracortical Facilitation in the Human Motor Cortex Van den Bos, Mehdi A. J. Menon, Parvathi Howells, James Geevasinga, Nimeshan Kiernan, Matthew C. Vucic, Steve Front Neurosci Neuroscience Short interval intracortical facilitation (SICF) may be elicited by a paired pulse transcranial magnetic stimulation (TMS) paradigm, whereby a suprathreshold first stimulus (S1) precedes a perithreshold second stimulus (S2). Other facilitatory circuits can be probed by TMS such as intracranial facilitation, however the cortical contributions to these circuits may lie partially outside of M1. SICF as such represents a unique analog to M1 inhibitory circuits such as short interveal intracortical circuits. The aim of the present study was to provide insight into the physiological processes underlying the development of SICF using the threshold tracking TMS technique which was recently demonstrated to have significant reliability. TMS studies were undertaken on 35 healthy controls, using either a 90 mm circular and 70 mm figure of eight coil, and one of two targets (0.2 and 1.0 mV) tracked. The motor evoked potential (MEP) responses were recorded from the abductor pollicis brevis. SICF was consistently evident between interstimulus intervals (ISI) of 1–5 ms (P < 0.001), with two peaks occurring ISIs 1.5 and 3 ms when using the circular coil. A significant SICF reduction (F = 5.631, P < 0.05) was evident with the higher tracking target, while SICF increased when stimulating with the figure of eight coil. While there was a correlation between SICF and CSP duration, there was no relationship between SICF and SICI or ICF. Age appeared to have no influence on SICF, SICI, or ICF. Findings from the present work suggest that SICF appears to be mediated by I-wave facilitation. Frontiers Media S.A. 2018-04-11 /pmc/articles/PMC5904283/ /pubmed/29695952 http://dx.doi.org/10.3389/fnins.2018.00240 Text en Copyright © 2018 Van den Bos, Menon, Howells, Geevasinga, Kiernan and Vucic. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Neuroscience
Van den Bos, Mehdi A. J.
Menon, Parvathi
Howells, James
Geevasinga, Nimeshan
Kiernan, Matthew C.
Vucic, Steve
Physiological Processes Underlying Short Interval Intracortical Facilitation in the Human Motor Cortex
title Physiological Processes Underlying Short Interval Intracortical Facilitation in the Human Motor Cortex
title_full Physiological Processes Underlying Short Interval Intracortical Facilitation in the Human Motor Cortex
title_fullStr Physiological Processes Underlying Short Interval Intracortical Facilitation in the Human Motor Cortex
title_full_unstemmed Physiological Processes Underlying Short Interval Intracortical Facilitation in the Human Motor Cortex
title_short Physiological Processes Underlying Short Interval Intracortical Facilitation in the Human Motor Cortex
title_sort physiological processes underlying short interval intracortical facilitation in the human motor cortex
topic Neuroscience
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5904283/
https://www.ncbi.nlm.nih.gov/pubmed/29695952
http://dx.doi.org/10.3389/fnins.2018.00240
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