A new cell type is implicated in epilepsy caused by traumatic brain injury

March 11, 2014

Traumatic brain injury is a risk factor for epilepsy, though the relationship is not understood. A new study in mice, published in Cerebral Cortex, identifies increased levels of a specific neurotransmitter as a contributing factor connecting traumatic brain injury (TBI) to post-traumatic epilepsy. The findings suggest that damage to brain cells called interneurons disrupts neurotransmitter levels and plays a role in the development of epilepsy after a traumatic brain injury.

The research team, led by David Cantu and Chris Dulla, studied the effect of traumatic on the levels of the neurotransmitter gamma-aminobutyric acid (GABA) in the , the portion of the brain associated with higher level functions such as information processing.

Normally, GABA inhibits neurotransmission in the brain, while its precursor, glutamate, stimulates neurotransmission. When the cortex is damaged by brain injury, however, the cells that create GABA, called interneurons, die. This leads to a toxic buildup of glutamate, which overstimulates brain activity. The study identifies this disrupted balance of GABA and glutamate as a factor in increased epileptic brain activity. The findings suggest that traumatic brain injuries cause damage to the interneurons responsible for creating GABA.

"If we can preserve these important cells, we may be able to decrease the negative impacts of ," said first author David Cantu, Ph.D., a postdoctoral scholar at Tufts University School of Medicine, and member of the NIH-funded Institutional Research Career and Academic Development Awards (IRACDA) Program, Training in Education and Critical Research Skills (TEACRS), at the Sackler School of Graduate Biomedical Sciences at Tufts. "Interneurons play a critical role in preventing seizures from starting."

"This research increases our basic understanding of the effects of head trauma, particularly for those severe single injuries that can and do happen in military service and contact sports," said Naomi Rosenberg, Ph.D., dean of the Sacker School and vice dean for research at Tufts University School of Medicine. "The IRACDA program provides transformational experiences to outstanding post-doctoral researchers, like David, who want to combine training in research with training in teaching at institutions serving under-represented minorities."

Epilepsy affects more than 2.3 million Americans, according to estimates by the Centers for Disease Control and Prevention. The Epilepsy Foundation estimates that 15 to 34 percent of TBI patients have post-traumatic epilepsy while the rate of post-traumatic epilepsy rises to as high as 52 percent among TBI patients who have served in active military roles.

"Millions of Americans experience a TBI every year, often with devastating and life-altering results. A TBI can cause issues with walking, talking, and living independently. Brain injury is the 'signature injury' of those in the military who have served in Iraq and Afghanistan. There are also many sports-related brain injuries. Fall-related injuries can disrupt the brain development of children, and upset the delicate brain systems among the elderly," said senior author Chris Dulla, Ph.D. He is an assistant professor of neuroscience at Tufts University School of Medicine, and member of the Cell, Molecular & Developmental Biology, and Neuroscience program faculties at the Sackler School.

"Our study is an important step in identifying the mechanistic relationship between TBI and post-traumatic epilepsy. The study describes a potential outline of what happens after brain injury to trigger epilepsy, but the neurological causes of how TBI kills interneurons specifically after the initial injury are still unknown. Understanding how brain injury disrupts normal brain function will allow scientists and physicians to develop new treatments and therapies to help people recover from post-traumatic epilepsy," said Cantu.

The work was done in collaboration with Giuseppina Tesco, M.D., Ph.D., associate professor of neuroscience at Tufts and member of the neuroscience graduate program faculty at the Sackler School. It is part of the team's larger effort to understand brain injury and .

Explore further: Is there a period of increased vulnerability for repeat traumatic brain injury?

More information: Cantu D, Walker K, Andresen L, Taylor-Weiner A, Hampton D, Tesco G, Dulla C. "Traumatic brain injury increases cortical glutamate network activity by compromising GABAergic control." Cerebral Cortex. Published online Mar 7, 2014: DOI: 10.1093/cercor/bhu041

Related Stories

Have a brain injury? You may be at higher risk for stroke

June 26, 2013

People who have a traumatic brain injury (TBI) may be more likely to have a future stroke, according to research that appears in the June 26, 2013, online issue of Neurology, the medical journal of the American Academy of ...

Recommended for you

New insights on how cocaine changes the brain

November 25, 2015

The burst of energy and hyperactivity that comes with a cocaine high is a rather accurate reflection of what's going on in the brain of its users, finds a study published November 25 in Cell Reports. Through experiments conducted ...

Can physical exercise enhance long-term memory?

November 25, 2015

Exercise can enhance the development of new brain cells in the adult brain, a process called adult neurogenesis. These newborn brain cells play an important role in learning and memory. A new study has determined that mice ...

Umbilical cells help eye's neurons connect

November 24, 2015

Cells isolated from human umbilical cord tissue have been shown to produce molecules that help retinal neurons from the eyes of rats grow, connect and survive, according to Duke University researchers working with Janssen ...

Brain connections predict how well you can pay attention

November 24, 2015

During a 1959 television appearance, Jack Kerouac was asked how long it took him to write his novel On The Road. His response – three weeks – amazed the interviewer and ignited an enduring myth that the book was composed ...

No cable spaghetti in the brain

November 24, 2015

Our brain is a mysterious machine. Billions of nerve cells are connected such that they store information as efficiently as books are stored in a well-organized library. To this date, many details remain unclear, for instance ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.