From induction to movement - a detailed biophysical model of TMS motor activation (TMSModel)

Lead Agency grant projects - GACR GF26-26316L [Registered results] 2026 - 2028

Principal Investigator: Dr. Shih Cheng Chien

Transcranial magnetic stimulation (TMS) of the primary motor cortex (M1) elicits muscle aktivity that can be observed by measuring motor-evoked potentials (MEP). This procedure is an essential tool for studying the central motor pathways. However, the complex processing along the motor pathway is only partly understood, and conclusions from experiments still need to be clarified and speculative. Here, we plan to develop an experimental and modeling framework to study the process.

Apart from recording hand muscle activity in response to stimulation, we also perform non-invasive observations of descending spike volleys (D- and I-waves) via surface electrodes placed on the head, neck, back, and arm. Stimulation and all measurements are linked together by biophysical modeling, taking into account all available knowledge about the anatomy and physiology of the brain and the cortico-spinal-peripheral pathways.

This project aims to create a comprehensive biophysical model that successfully explains the dependence of MEPs recorded from hand muscles and D-I-waves measured from the spinal cord on the parameters of TMS.