Hemodynamic correlates of fluctuations in neuronal excitability: A simultaneous Paired Associative Stimulation (PAS) and functional near infra-red spectroscopy (fNIRS) study

Zhengchen Cai; Giovanni Pellegrino; Amanda Spilkin; Edouard Delaire; Makoto Uji; Chifaou Abdallah; Jean-Marc Lina; Shirley Fecteau; Christophe Grova

Neuroimage: Reports (Sep 2022)

Hemodynamic correlates of fluctuations in neuronal excitability: A simultaneous Paired Associative Stimulation (PAS) and functional near infra-red spectroscopy (fNIRS) study

Zhengchen Cai,
Giovanni Pellegrino,
Amanda Spilkin,
Edouard Delaire,
Makoto Uji,
Chifaou Abdallah,
Jean-Marc Lina,
Shirley Fecteau,
Christophe Grova

Affiliations

Zhengchen Cai: Multimodal Functional Imaging Lab, Department of Physics and PERFORM Centre, Concordia University, Montréal, Québec, Canada; Corresponding author. Multimodal Functional Imaging Lab, Department of Physics and PERFORM Centre, Concordia University. Loyola Campus, Office SP 365.23 7141 Sherbrooke Street West, Montreal, QC, H4B 1R6, Canada.
Giovanni Pellegrino: Neurology and Neurosurgery Department, Montreal Neurological Institute, McGill University, Montréal, Québec, Canada; Multimodal Functional Imaging Lab, Biomedical Engineering Department, McGill University, Montréal, Québec, Canada
Amanda Spilkin: Multimodal Functional Imaging Lab, Department of Physics and PERFORM Centre, Concordia University, Montréal, Québec, Canada
Edouard Delaire: Multimodal Functional Imaging Lab, Department of Physics and PERFORM Centre, Concordia University, Montréal, Québec, Canada
Makoto Uji: Multimodal Functional Imaging Lab, Department of Physics and PERFORM Centre, Concordia University, Montréal, Québec, Canada
Chifaou Abdallah: Neurology and Neurosurgery Department, Montreal Neurological Institute, McGill University, Montréal, Québec, Canada
Jean-Marc Lina: Département de Génie Electrique, École de Technologie Supérieure, Montréal, Québec, Canada; Centre De Recherches En Mathématiques, Montréal, Québec, Canada
Shirley Fecteau: CERVO Brain Research Centre, Centre Intégré Universitaire De Santé Et De Services Sociaux De La Capitale-Nationale, Canada; Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, Canada
Christophe Grova: Multimodal Functional Imaging Lab, Department of Physics and PERFORM Centre, Concordia University, Montréal, Québec, Canada; Neurology and Neurosurgery Department, Montreal Neurological Institute, McGill University, Montréal, Québec, Canada; Multimodal Functional Imaging Lab, Biomedical Engineering Department, McGill University, Montréal, Québec, Canada; Centre De Recherches En Mathématiques, Montréal, Québec, Canada

Journal volume & issue: Vol. 2, no. 3
p. 100099

Abstract

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Background: The relationship between task-related hemodynamic activity and brain excitability is poorly understood in humans as it is technically challenging to combine simultaneously non-invasive brain stimulation and neuroimaging modalities. Cortical excitability corresponds to the readiness to become active and as such it may be linked to metabolic demand. Hypotheses: Cortical excitability and hemodynamic activity are positively linked so that increases in hemodynamic activity correspond to increases in excitability and vice-versa. Methods: Magnitudes of excitability and hemodynamic activity were investigated via simultaneous Transcranial Magnetic Stimulation (TMS) and functional Near Infrared Spectroscopy (fNIRS). Sixteen healthy subjects participated in a sham-controlled, pseudorandomized, counterbalanced study with PAS (PAS10/PAS25/Sham) on the right primary motor cortex (M1). The relationship between M1 excitability (Motor Evoked Potentials, MEP) and hemodynamic responses to finger tapping reconstructed via personalized fNIRS was assessed. Results: Hemodynamic activity exhibited a significant correlation with cortical excitability: increased HbO and HbR (absolute amplitude) corresponded to increased excitability and vice-versa (r = 0.25; p = 0.03 and r = 0.16; p = 0.17, respectively). The effect of PAS on excitability and hemodynamic activity showed a trend of positive correlation with MEP ratios (post-PAS/pre-PAS) linked to HbO and HbR ratios (r = 0.19, p = 0.29; r = 0.18, p = 0.30, respectively). Conclusions: TMS-fNIRS is a suitable technique for simultaneous investigation of excitability and hemodynamic responses and indicates a relationship between these two cortical properties. PAS effect is not limited to cortical excitability but also impacts hemodynamic processes. These findings have an impact on the application of neuromodulatory interventions in patients with neuropsychiatric disorders.

Published in Neuroimage: Reports

ISSN: 2666-9560 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Medicine: Internal medicine: Neurosciences. Biological psychiatry. Neuropsychiatry
Website: https://www.journals.elsevier.com/neuroimage-reports

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