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bioRxiv · 10.1101/2023.01.20.524867

Mapping cortical excitability in the human dorsolateral prefrontal cortex

Gogulski, J.·Cline, C. C.·Ross, J. M.·Truong, J.·Sarkar, M.·Parmigiani, S.·Keller, C. J.
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Abstract

ObjectiveTo characterize early TEPs anatomically and temporally (20-50 ms) close to the TMS pulse (EL-TEPs), as well as associated muscle artifacts (<20 ms), across the dlPFC. We hypothesized that TMS location and angle influence EL-TEPs, and that EL-TEP amplitude is inversely related to muscle artifact. Additionally, we sought to determine an optimal group-level TMS target and angle, while investigating the potential benefits of a personalized approach. MethodsIn 16 healthy participants, we applied single-pulse TMS to six targets within the dlPFC at two coil angles and measured EEG responses. ResultsStimulation location significantly influenced EL-TEPs, with posterior and medial targets yielding larger EL-TEPs. Regions with high EL-TEP amplitude had less muscle artifact, and vice versa. The best group-level target yielded 102% larger EL-TEP responses compared to other dlPFC targets. Optimal dlPFC target differed across subjects, suggesting that a personalized targeting approach might boost the EL-TEP by an additional 36%. SignificanceEarly local TMS-evoked potentials (EL-TEPs) can be probed without significant muscle-related confounds in posterior-medial regions of the dlPFC. The identification of an optimal group-level target and the potential for further refinement through personalized targeting hold significant implications for optimizing depression treatment protocols. HighlightsO_LIEarly local TMS-evoked potentials (EL-TEPs) varied significantly across the dlPFC as a function of TMS target. C_LIO_LITMS targets with less muscle artifact had significantly larger EL-TEPs. C_LIO_LISelection of a postero-medial target increased EL-TEPs by 102% compared to anterior targets. C_LI

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Gogulski, J., Cline, C. C., Ross, J. M., Truong, J., Sarkar, M., Parmigiani, S., Keller, C. J.. 2023-01-20. Mapping cortical excitability in the human dorsolateral prefrontal cortex. https://doi.org/10.1101/2023.01.20.524867

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