Related Experiment Video
Updated: Aug 16, 2025

Utilizing Transcranial Magnetic Stimulation to Study the Human Neuromuscular System
Published on: January 20, 2012
Finding synaptic couplings from a biophysical model of motor evoked potentials after theta-burst transcranial
Marcus T Wilson1, Mitchell R Goldsworthy2, Ann-Maree Vallence3
1Te Aka Mātuatua-School of Science, University of Waikato, Hamilton, New Zealand.
Objective:
We aimed to use measured input-output (IO) data to identify the best fitting model for motor evoked potentials.
Methods:
We analyzed existing IO data before and after intermittent and continuous theta-burst stimulation (iTBS & cTBS) from a small group of subjects (18 for each). We fitted individual synaptic couplings and sensitivity parameters using variations of a biophysical model. A best performing model was selected and analyzed.
Results:
cTBS gives a broad reduction in MEPs for amplitudes larger than resting motor threshold (RMT). Close to threshold, iTBS gives strong potentiation. The model captures individual IO curves. There is no change to the population average synaptic weights post TBS but the change in excitatory-to-excitatory synaptic coupling is strongly correlated with the experimental post-TBS response relative to baseline.
Conclusions:
The model describes population-averaged and individual IO curves, and their post-TBS change. Variation among individuals is accounted for with variation in synaptic couplings, and variation in sensitivity of neural response to stimulation.
Significance:
The best fitting model could be applied more broadly and validation studies could elucidate underlying biophysical meaning of parameters.
More Related Videos
09:52Measuring and Manipulating Functionally Specific Neural Pathways in the Human Motor System with Transcranial Magnetic Stimulation
Published on: February 23, 2020
11:11Effects of Transcranial Alternating Current Stimulation on the Primary Motor Cortex by Online Combined Approach with Transcranial Magnetic Stimulation
Published on: September 23, 2017
Related Concept Videos
Motor Unit Stimulation
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
Muscle Stimulation Frequency
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...