Modulating Brain Networks With Transcranial Magnetic Stimulation Over the Primary Motor Cortex: A Concurrent TMS/fMRI Study
JeYoung Jung, A. Bungert, R. Bowtell, S. Jackson
bioRxiv December 18, 2019 preprint DOI: 10.3389/fnhum.2020.00031 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Experimental neuroimaging study (concurrent TMS/fMRI) |
|---|---|
| Population | Human participants receiving TMS to the hand area of the primary motor cortex |
| Intervention | Transcranial magnetic stimulation (TMS) |
| Dose | 1Hz train of TMS pulses |
| Key findings | A short 1 Hz TMS train to the M1 hand area decreased motor network activity during a motor task and increased deactivation of task-uninvolved networks at rest. Stimulation activated bodily self-consciousness networks (insular and rolandic operculum systems) in both states, most strongly at rest, and modulated default mode and attention networks and their connectivity. |
Abstract
Stimulating the primary motor cortex (M1) using transcranial magnetic stimulation (TMS) causes unique multisensory experience such as the targeted muscle activity, afferent/reafferent sensory feedback, tactile sensation over the scalp and ‘click’ sound. Although the human M1 has been intensively investigated using TMS, the experience of the M1 stimulation has not been elucidated at the whole brain. Here, using concurrent TMS/fMRI, we investigated the acute effect of the M1 stimulation of functional brain networks during task and at rest. A short 1Hz train of TMS pulses applied to individuals’ hand area in the M1 during motor execution or at rest. Employing the independent component analysis (ICA), we showed the M1 stimulation decreased the motor networks activity when the networks were engaged in the task and increased the deactivation of networks when the networks were not involved in the ongoing task. The M1 stimulation induced the activation in the key networks involved in bodily self-consciousness (BSC) including the insular and rolandic operculum systems regardless of states. The degree of activation in these networks was highest at rest compared to during task, showing the state-dependent TMS effect. Furthermore, we demonstrated that the M1 stimulation modulated other domain general networks such as the default mode network and attention network and the inter-network connectivity between these networks. Our results showed that the M1 stimulation induced the widespread changes in the brain at the targeted system as well as non-motor, remote brain networks, specifically related to the BSC. Our findings shed light on understanding the neural mechanism of the complex and multisensory experience of the M1 stimulation.