Peripheral Nerve Degeneration: How the Shock Affects Nerve Repair

     In science, there has been an uptick in the use of electrical stimulation to "biohack" our bodies and brains, whether it is to wake us up or for physical therapies. As a result, many new studies have emerged to understand the body's natural stimulation and create tech that mimics it to address a variety of issues. Currently, scientists are digging deeper to determine which frequencies are the best for humans to create devices specifically for nerve degeneration.   

         During our class, we heard from Dr. Vincent Chen, whose focus was Power Spectral Density (PSD). PSD describes the power of a time-domain signal, or how a random process can be distributed across different frequencies. Chen's hypothesis is as follows: we should manipulate the waveform shape to target NMDA and AMPA receptors, which act as switches that turn on nerve growth. His clinical success with "random noise" stimulation is due to the rich PSD. He also questions modern electrical stimulation methods, as square waves commonly used contain harmonics, echoes of higher frequencies hidden within the signal. With these higher frequencies, it makes it harder to determine which signal is most optimal for nerve regeneration actively. Just following the frequency to him is imprecise because the signal will degrade as soon as it passes through the skin and tissue. He notes that the nerve membrane acts as a capacitor, resisting sudden changes, so changing the type of wave could also affect the nerve differently.  By controlling the voltage gradient, he can target very specific receptors. Chen's approach is highly specific, and with the future of implantable devices, it blows all past nerve studies out of the water.   

A different study conducted by Dr. Lingmei Ni uses very traditional electrical stimulation approaches to alleviate the effects of nerve damage. Ni uses multiple types of electrical stimulation, including NMES (neuromuscular), and low-frequency pulses to contract the muscles, helping prevent muscle atrophy directly. TENS is transcutaneous, blocking the pain signals with varying high and low frequencies. FES is the functional frequency, which can help paralyzed limbs return to function. These therapies have been used for a long time, but Ni has clinical data on specific frequencies to support her statement. Her studies show that 1 hour of 20Hz stimulation is proficient to accelerate axon growth after carpal tunnel surgery. Electrical stimulation increases BDNF and cAMP, which act as fuel for a growing neuron. However, even Dr. Ni points out how there is no standard for electrical stimulation. It varies between patients, parts of the body, and at times can seem almost random.   

These studies, when read together, can be seen as the future of electrical stimulation. Dr. Ni has a wide breadth of knowledge and clinical data on electrical stimulation, helping regenerate axons faster. Dr. Chen takes it one step further; no longer will the frequency or even type of wave vary from person to person. Rather, using PSD data, we can build stimulators that do not cause nerve fatigue or unwanted pain from high-frequency harmonies. With this amalgamation of information, other scientists can take this data to build more biohacking devices to help humans live more comfortable lives following nerve degeneration.   

Chen, VincentC.-F., et al. "Accelerating Peripheral Nerve Regeneration Using Electrical  Stimulation of Selected Power Spectral Densities." Neural Regeneration Research,  vol. 17, no. 4, 2022, p. 781, https://doi.org/10.4103/1673-5374.322458.  

Ni, Lingmei, et al. "Electrical Stimulation Therapy for Peripheral Nerve Injury." National  Center for Biotechnology Information, U.S. National Library of Medicine, 23 Feb.  2023, pmc.ncbi.nlm.nih.gov/.  

Mirco-coil Stimulation

    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.

When a Concussion “Heals”, Is the Brain Really Back to Normal?

One of the most striking points for a talk I attended this semester on concussion was the idea that recovery is not always as complete as it seems. Dr. Jennifer Krizman explained that even after someone is medically cleared and their symptoms have resolved, subtle effects on the brain function, especially memory, can persist. This challenged the common assumption that once a concussion is “healed”, the brain automatically returns to its pre-injury state. 

This idea has become increasingly relevant in recent years as concussion awareness has increased. Current research supports this, underscoring that individuals who have had concussions may still experience issues with memory, attention, processing speed, and sleep. Even “mild” concussions can lead to lingering effects years after the injury (Denworth, 2024). This article also highlights research showing structural changes in the brain long after the concussion, supporting that the traditional symptom-based evaluations aren’t always enough to assess long-term memory. 

Dr. Krizman’s talk made a very similar point: the brain doesn’t always recover completely just because a person’s symptoms have resolved. Memory issues can be subtle and easily overlooked, especially when someone feels physically fine. This corresponds with what the Scientific American article describes as the long tail of concussion effects. This is where difficulties such as memory lapses or concentration problems can present even when other symptoms resolve (Denworth, 2024). 

Emerging research is now using more sensitive brain-based measures to track recovery. For instance, a 2025 study reported that athletes who have suffered a concussion still showed changes in brain-blood flow and structure for up to a year after they were medically cleared. These changes occurred in areas of the brain involved in thinking and memory, suggesting that even when symptoms have faded, the brain may not have fully regained its pre-injury state (American Academy of Neurology, 2025). This helps us understand why some people continue to have memory lapses or difficulty concentrating long after they feel “normal”. 

Understanding that the brain changes can shift our thinking of concussion as a short-lived injury that fully heals in a few weeks, it may be more accurate to view them as injuries that leave lasting changes in brain function. This understanding could have real-world impacts on how athletes and patients are monitored during and after their concussions, possibly even a recovery plan may be needed that extends beyond symptom resolution. 

To conclude, recognizing that brain changes may persist even after people feel physically better can lead to better guidelines for return-to-play, return-to-learn, and long-term monitoring. Research has validated the experience of people whose memory and cognitive performance remain altered and impaired after concussions; without such research, these accounts might be overlooked and dismissed because patients’ symptoms appear to be “gone”.

References:

Denworth, L. (2024, November 19). Concussions Are Remarkably Common and Can Cause Long-Term Problems. Scientific American. https://www.scientificamerican.com/article/concussions-are-remarkably-common-and-can-cause-long-term-problems/ 

American Academy of Neurology. (2025, March 14). Do brain changes remain after recovery from concussion?. ScienceDaily. Retrieved February 27, 2026 from www.sciencedaily.com/releases/2025/03/250312190835.htm

Understanding Language By: Isabel Korstanje

  Understanding Language

 

The ability to communicate and understand is taken for granted on a daily basis. A simple typo, stutter, whisper can change the trajectory of various events. To understand is to be able to observe and learn. Our senses are supreme to this concept of ‘understanding’ and is something that we as humans utilizes every second of every minute. To see, is to identify and analyze. It is a way to provide a name, discernment, and for some species another day of survival. To be able to hear allows us to sense or understand without having to identify. Both together can evolve and create a stronger comprehension of communication. 

In a seminar done recently at Loyola University, Natalia Zielinski and Elizabeth M Wakefield spoke on the correlation between physical gestures and understanding language. They focused on a study done on bilingual students and their understanding of a spoken message, specifically if that understanding was enhanced by gestures.2 This was done through storytelling, with specific details or descriptions being heavily emphasized through physical gestures. The children were then individually asked about certain details mentioned throughout the story. This determined if the child was more likely to recall a certain event or turning point in the story when gestures were used.2 The focus was the correlation between a visual stimulus and language proficiency. 

An article by Cody Cottier, “‘Mind-blowing’ baby chick study challenges a theory of how humans evolved language”, focused on baby chicks finding another way in which language can be processed and strengthened. The study in which the article follows focuses on how animals utilize their sense of hearing to understand and form connections to others from the same or different species. The bouba-kiki study revealed that baby chickens use specific sounds to identify shapes, forming a linkage with sounds and visual information.1 The sound reveals not only the source, but the pitch and volume, which may also reveal further physical details of said source. 

Both articles present a strengthening of language understanding via auditory and visual information. Similarly, both share the same ‘age group’ of both chickens and humans, with early development playing a critical part of the studies. The senses are presented as crucial during the developmental stages of early life, with the brain combining what we hear and see when analyzing or recalling. 

 

 

                                         

Refrences

 

(1)     Blum, D. (2024). Baby chicks pass the bouba–kiki test, challenging a theory of language. Scientific American. https://www.scientificamerican.com/article/baby-chicks-pass-the-bouba-kiki-test-challenging-a-theory-of-language/

(2)     Zielinski, N., & Wakefield, E. M. (2021). Language proficiency impacts the benefits of co-speech gesture for narrative understanding through a visual attention mechanism. Loyola University, Access Date, March 2nd, 2026