scholarly journals Comparison of Induced Fields in Virtual Human and Rat Heads by Transcranial Magnetic Stimulation

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Ya-Wen Lu ◽  
Mai Lu
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Animal Studies ◽  
Brain Research ◽  
Three Dimensional ◽  
Virtual Human ◽  
Impedance Method ◽  
Magnetic Flux Density ◽  
Biological Mechanisms ◽  
First Time

Transcranial magnetic stimulation (TMS) shows significant values in both brain research and therapeutic applications of cognitive neuroscience, neurophysiology, and psychiatry. Animal studies of TMS provide a potential way for learning the biological mechanisms of actions of TMS. In this paper, we presented the comparison of human TMS and rat TMS by using the conventional figure-of-eight coil for the first time. Three-dimensional distributions of magnetic flux density and induced electric field in both virtual human and rat heads were obtained through the 3D impedance method. The results indicated that smaller TMS coils are needed for stimulation of the rat brain. A rat-specific figure-of-eight coil was designed by considering the coil radii, number of coil turns, and the injected coil currents. We found that the numerically designed Fo8 coil can be applied to the rat TMS with improved focality while also keeping high stimulation intensities.

Modulation of cerebello-cerebral resting state networks by site-specific stimulation

2015 ◽  
Vol 114 (4) ◽  
pp. 2084-2086 ◽  
Author(s):  
Anuj Rastogi ◽  
Ayda Ghahremani ◽  
Robin Cash
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Cognitive Processes ◽  
Resting State ◽  
Magnetic Stimulation ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Resting State Networks ◽  
Site Specific ◽  
Specific Stimulation ◽  
First Time ◽  
Broad Role

Converging evidence from neuroimaging and neuromodulation literature suggests that the cerebellum plays a broad role in motor as well as cognitive processes through its participation in resting-state networks. A recent study by Halko et al. ( J Neurosci 34: 12049–12056, 2014) demonstrates, for the first time, the ability to modulate functional connectivity of some of these distinct resting-state networks using site-specific repetitive transcranial magnetic stimulation (rTMS) of the cerebellum. In this Neuro Forum, we discuss and critically analyze this study, emphasizing important findings, potential therapeutic relevance, and areas worthy of further inquiry.

scholarly journals Non-predictive online spatial coding in the posterior parietal cortex when aiming ahead for catching

2017 ◽  
Author(s):  
Sinéad A. Reid ◽  
Joost C. Dessing
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Parietal Cortex ◽  
Magnetic Stimulation ◽  
Posterior Parietal Cortex ◽  
Target Position ◽  
Occipital Cortex ◽  
Spatial Coding ◽  
Posterior Parietal ◽  
First Time

Catching movements must be aimed ahead of the moving ball, which may require predictions of when and where to catch. Here, using Transcranial Magnetic Stimulation we show for the first time that, although interception movements were clearly aimed at the predicted final target position, the Superior Parietal Occipital Cortex (SPOC) displayed non-predictive online spatial coding. The ability to aim ahead for catching must thus arise downstream within the parietofrontal network for reaching.

scholarly journals Closed-loop optimization of transcranial magnetic stimulation with electroencephalography feedback

2021 ◽  
Author(s):  
Aino E. Tervo ◽  
Jaakko O. Nieminen ◽  
Pantelis Lioumis ◽  
Johanna Metsomaa ◽  
Victor H. Souza ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Electric Field ◽  
Magnetic Stimulation ◽  
Closed Loop ◽  
Brain Research ◽  
Brain Activity ◽  
Single Trial ◽  
Field Orientation ◽  
Electric Field Direction ◽  
Set Up

Background: Transcranial magnetic stimulation (TMS) is widely used in brain research and treatment of various brain dysfunctions. However, the optimal way to target stimulation and administer TMS therapies, for example, where and in which electric-field direction the stimuli should be given, is yet to be determined. Objective: To develop an automated closed-loop system for adjusting TMS parameters online based on TMS-evoked brain activity measured with electroencephalography (EEG). Methods: We developed an automated closed-loop TMS–EEG set-up. In this set-up, the stimulus parameters are electronically adjusted with multi-locus TMS. As a proof of concept, we developed an algorithm that automatically optimizes the stimulation parameters based on single-trial EEG responses. We applied the algorithm to determine the electric-field orientation that maximizes the amplitude of the TMS–EEG responses. The validation of the algorithm was performed with six healthy volunteers, repeating the search twenty times for each subject. Results: The validation demonstrated that the closed-loop control worked as desired despite the large variation in the single-trial EEG responses. We were often able to get close to the orientation that maximizes the EEG amplitude with only a few tens of pulses. Conclusion: Optimizing stimulation with EEG feedback in a closed-loop manner is feasible and enables effective coupling to brain activity.

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