Electrode stimulation, such as deep brain stimulation (DBS), has been utilized in treating pain, seizures, and improving movement. It is achieved by directly applying an electrical pulse to neural tissue via a surgically implanted electrode. There have been numerous successes in treatments involving electrode stimulation. However, there are also risks and limitations such as inaccurate neural targeting, potential for tissue damage which may trigger inflammation and immune responses, and corrosion, though rarely, of the electrode itself.
A new magnetic stimulation technique that aims to improve and reduce the limitations of current electrode and magnetic stimulation techniques is micro-magnetic stimulation (µMS). µMS has been found to have improved specificity of neural stimulation, it utilizes biocompatible materials that reduce inflammation and allow for deep brain stimulation without damaging neural tissue.
I recently had the pleasure of attending a talk by Dr. Ye Hui, a biomedical engineer focusing his research on electromagnetic stimulation. His talk focused on his recent paper: “Restore axonal conductance in a locally demyelinated axon with electromagnetic stimulation.” This paper investigated a demyelinated axon model built in NEURON under circular micro-coil stimulation. Demyelinated axons are often the result of neurodegenerative diseases, ischemic injuries, among other factors. Due to demyelination, neural signals are blocked or slowed depending on the severity of the demyelination. But how to restore those neural signals is not fully understood. The main findings of Dr.Ye’s paper found that subthreshold micro-coil stimulation, which is just below the needed stimulus to generate an action potential, combined with the depolarization of an action potential was enough to restore axonal conductance. In other words, a subthreshold stimulus saved the incoming action potential by giving it the boost to get past the demyelinated area and continue down the axon. Restoration was dependent on the amplitude and frequency of the stimulus which was found to have the most consistent results at 5000Hz. Dr.Ye’s research provides vital insights into not only the development of micro-coil stimulation, but also in treatments of focally segmented demyelination cases.
An article titled: “Micro-Coil Neuromodulation at Single-Cell and Circuit Levels for Inhibiting Natural Neuroactivity, Neutralizing Electric Neural Excitation, and Suppressing Seizures.” by Kim et al., investigates µMS in both research and therapeutic applications. While Dr.Ye’s paper focused on restoring axonal conductance, this article focuses on precise neural inhibition, which is similarly not well understood, with µMS. Using cortical in vivo two-photon imaging, the researchers were able to find that µMS suppressed single cells and increasing µMS magnitude further increased the number of inhibited cells. µMS was also found to be able to suppress hyperactive neural firing caused by pharmacologically induced seizures, with more research, this could potentially lead to the suppression of epileptic seizures. These findings emphasize the importance of further researching the potential applications of µMS technology in clinical settings.
As this is still a new field of research, there is still much that is not known about µMS. However, both Dr.Ye, Kim et al., and many others are paving the way for µMS. One of the most compelling aspects of µMS research are its increasingly promising applications to not yet well understood branches of neuroscience. With its application to restoring axonal conductance in locally demyelinated axons to suppressing seizures, µMS has the potential to become a treatment for a variety of neurological disorders.
Citations:
Ye, Hui et al. “Restore axonal conductance in a locally demyelinated axon with electromagnetic stimulation.” Journal of Neural Engineering vol. 22,1 016042. 14 Feb. 2025.
Ye, Hui et al. “Improving focality and consistency in micromagnetic stimulation.” Frontiers in computational neuroscience vol. 17, 1105505. 2 Feb. 2023.
Kim, Kayeon et al. “Micro-Coil Neuromodulation at Single-Cell and Circuit Levels for Inhibiting Natural Neuroactivity, Neutralizing Electric Neural Excitation, and Suppressing Seizures.” Advanced science (Weinheim, Baden-Wurttemberg, Germany) vol. 12,22 (2025): e2416771.
No comments:
Post a Comment