Scientists have discovered that by controlling the timing of neurostimulation pulses, which are used to activate the brain’s own electrical signaling mechanisms, they can adjust the strength of synaptic connections between nerve cells. This can help enhance or decrease specific connections.
Timing is crucial not just on the dance floor, but also for individuals recovering from mild traumatic brain injury (mTBI).
In a study published in the Journal of Neurotrauma, researchers from Virginia Tech’s Fralin Biomedical Research Institute at VTC have demonstrated that manipulating the timing pattern of neurostimulation can rebalance the strength of synaptic connections between nerve cells. This process can selectively enhance or diminish these connections. While timing patterns of electrical signaling are important in a healthy brain, they also play a significant role in adjusting the strength of synaptic connections post-brain injury, particularly in strengthening them using patterns that would normally weaken such connections in a healthy brain.
The research emphasizes the importance of considering more natural, random patterns of activity impulses for neurostimulation to effectively treat brain disorders, including concussions and other mTBIs. According to the Centers for Disease Control and Prevention, over 2.1 million head injuries are treated in U.S. emergency departments annually, with many others going unnoticed.
“Our findings suggest that varying brain stimulation patterns could aid in treating mild traumatic brain injuries,” stated Michael Friedlander, one of the co-authors of the study and the executive director of the Fralin Biomedical Research Institute at VTC, as well as the Vice President for Health Sciences and Technology at Virginia Tech.
“By adjusting factors like timing, frequency, and consistency of stimulation, we may strengthen specific brain connections, potentially enhancing brain function post-injury. The brain’s electrical and synaptic signaling is usually irregular,” Friedlander explained. “Therefore, we aimed to leverage this natural variability in brain activity to see if mimicking these patterns could activate signaling pathways to readjust connections in neuronal networks that have been compromised after injury.”
Brain stimulation is increasingly utilized to treat various neurological and psychiatric conditions, such as depression, Parkinson’s disease, chronic pain, and Alzheimer’s disease. However, little attention has been given to stimulation patterns beyond frequency.
“While our study focused on mTBI in laboratory rats, it could offer insights for treating other brain conditions in humans,” added Friedlander.
This study is one of the initial investigations into the effects of precisely controlling the timing patterns of neurostimulation.
The researchers observed that irregular patterns at specific frequencies impacted injured brains differently than healthy brains, strengthening connections with other nerve cells in the injured brain while weakening them in healthy brains.
“Neurostimulation can be delivered in regular, metronome-like intervals or in a more irregular manner,” explained Quentin Fischer, a research assistant professor at the Fralin Biomedical Research Institute in the Friedlander laboratory and co-author of the study.
“It’s akin to the distinction between a well-organized concerto and jazz improvisation, where musicians play with different patterns,” Fischer noted. “We found that highly irregular stimulation patterns in a healthy brain reduced the strength of neuron connections. However, in an injured brain, the same irregular pattern of stimulation strengthened these connections.”
These findings highlight the significance of timing signals in optimizing neurostimulation therapies for mTBI and other brain disorders, offering potential avenues for more effective treatment strategies.
“There’s a noticeable difference in how synapses respond to various stimulation patterns in normal and injured brains,” Friedlander pointed out. “Despite its name, mild traumatic brain injury can have lasting effects on cognitive function, mood, and overall quality of life. This underscores the critical need to understand the most effective approaches for delivering optimized therapeutic neurostimulation.”
