Long-range neural activity evoked by premotor cortex stimulation: a TMS/EEG co-registration study

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Brain Imaging

Background:

• The premotor cortex is crucial for various cognitive and motor functions.
• Understanding its neural network connectivity is essential for deciphering brain activity.
• Previous research has explored premotor cortex functions, but detailed activity propagation remains under investigation.

Purpose of the Study:

• To investigate the spatial and temporal propagation of neural activity evoked in the dorsal premotor cortex.
• To characterize the long-ranging temporal and spatial networks influenced by dorsal premotor cortex stimulation.
• To utilize advanced neuroimaging techniques to map brain responses to targeted stimulation.

Main Methods:

• Employing single-pulse transcranial magnetic stimulation (TMS) combined with electroencephalography (EEG) in healthy volunteers.
• Comparing TMS-evoked activity to a sham condition under resting, eyes-closed state.
• Utilizing standardized low-resolution electromagnetic tomography (sLORETA) for spatial and temporal analysis of EEG data.

Main Results:

• TMS induced neural activity propagation primarily in contralateral sensorimotor and frontal cortices around 130 ms post-stimulation.
• Propagated activity was also observed in posterior (visual) regions between 70-130 ms.
• Evidence of "rebounding" activation in sensorimotor and frontal regions across various time windows was detected.

Conclusions:

• The study successfully mapped the propagation of neural activity originating from the dorsal premotor cortex.
• Findings elucidate the dynamic interplay within widespread neural networks, including sensorimotor, frontal, and visual areas.
• This research provides a detailed characterization of neural circuits activated by dorsal premotor cortex stimulation in humans.