Mild Traumatic Brain Injury May Alter the Brain’s Neuronal Circuit Excitability and Contribute to Brain Network Dysfunction
Even mild head injuries can cause significant abnormalities in brain function that last for several days, which may explain the neurological symptoms experienced by some individuals who have experienced a head injury associated with sports, accidents or combat, according to a study by Virginia Commonwealth University School of Medicine researchers.
These findings, published in the May issue of the Journal of Neuroscience, advance research in the field of traumatic brain injury (TBI), enabling researchers to better understand what brain structural or functional changes underlie posttraumatic disorders – a question that until now has remained unclear.
Previous research has shown that even a mild case of TBI can result in long-lasting neurological issues that include slowing of cognitive processes, confusion, chronic headache, posttraumatic stress disorder and depression.
The VCU team, led by Kimberle M. Jacobs, Ph.D. , associate professor in the Department of Anatomy and Neurobiology , demonstrated for the first time, using sophisticated bioimaging and electrophysiological approaches, that mild injury can cause structural disruption of axons in the brain while also changing the way the neurons fire in areas where they have not been structurally altered. Axons are nerve fibers in the brain responsible for conducting electrical impulses. The team used models of mild traumatic brain injury and followed morphologically identified neurons in live cortical slices.
“These findings should help move the field forward by providing a unique bioimaging and electrophysiological approach to assess the evolving changes evoked by mild TBI and their potential therapeutic modulation,” said co-investigator, John T. Povlishock, Ph.D. , professor and chair of the VCU School of Medicine’s Department of Anatomy and Neurobiology and director of the Commonwealth Center for the Study of Brain Injury.
According to Povlishock, additional benefit may also derive from the use of this model system with repetitive injuries to determine if repeated insults exacerbate the observed abnormalities.
Although it seems fairly common-sense to me, it’s good to see some official scientifically validated results going out to the rest of the world. I’m also encouraged to see the interest in more imaging and assessments of mild TBI. At the same time, however, I wonder if the focus on identifying “abnormalities” might be pathologizing basic diversity. What’s more, the next question that comes to my mind is “What constitutes ‘dysfunction’?” At what point do we establish that there’s an acceptable range of variability from brain to brain, and possibly come to the conclusion that some differences are actually not “dysfunctions” but simple variations in human experience?
It’s a double-edged sword, I think. On the one hand, we have scientific validation that mild TBI isn’t something you can just shrug off — it’s bigger than that and it can have real lasting consequences. On the other hand, isn’t life itself a brain-altering experience, and shouldn’t we be putting more focus on being/becoming increasingly functional in the face of unexpected changes, rather than focusing on the stuff that’s gone “wrong”?
As with any progress, it’s a mixed bag. And considering that we’re in really new territory with people actually paying attention to TBI/concussion and starting to take it seriously, I suspect we’re going to see a few years of people getting distressed and all worked up over a lot of things, before we manage to calm everyone down and get back to the business of living our lives to the best of our abilities.
We’re all learning, of course. Let’s keep learning and not get stuck on certain points along the way. And let’s use what we’re learning to move forward, not dig in on our personal and professional positions and stay stuck.