LOS ANGELES, Feb. 28 (Xinhua) -- A research team led by a scientist at the University of California, Riverside (UC Riverside) has found that brains treated with certain drugs within a few days of an injury have a dramatically reduced risk of developing epilepsy later in life, according to a release on Thursday.
The development of epilepsy is a major clinical complication after brain injury, and the disease can often take years to appear.
"Working on rats, whose immune response system models that of humans, we identified that after brain injury a certain immune system receptor makes the brain more excitable, which promotes development of epilepsy," said Viji Santhakumar, an associate professor of molecular, cell, and systems biology at UC Riverside and the lead author of the study that appears in the Annals of Neurology.
"If this receptor can be suppressed, preferably within a day after injury, the future development of epilepsy can be reduced if not entirely prevented," she said.
The receptor in question is the Toll-like receptor 4, or TLR4, an innate immune receptor. Following a brain injury, TLR4 increases excitability in the dentate gyrus of the hippocampus, the brain structure that plays a major role in learning and memory, according to the release.
The team specifically studied concussions, the kind suffered by many football players, which can lead to cell death in the hippocampus, affecting the processing of memory. Cell death activates the immune system, including TLR4. TLR4, in turn, increases excitability in the hippocampus.
"What our rat studies on traumatic brain injury show is that if we target early changes in excitability, we can alter long-term pathology," Santhakumar said. "Blocking TLR4 signaling shortly after brain injury reduces neuronal excitability in the hippocampus and seizure susceptibility. This seizure susceptibility is not reduced if we delay the blocking of TLR4 signaling after injury."
The study could have important implications for war veterans returning home with brain injuries, according to the release.
