Traumatic brain injury (TBI) affects more than half a million infants and children in the United States every year. New research shows that specific antibiotics used to inhibit the brain's inflammatory response can help adults, while at the same time negatively affecting children and infants.
There are no drugs available to treat TBI, but there are medical treatments used to improve the outcome in people who had suffered serious head injuries.
Medicine For Traumatic Brain Injury, Dangerous For Kids
The treatment was found to have a negative effect on the brains which did not complete the development process.
The study, published in the journal Experimental Neurology, was conducted by researchers at Drexel University College of Medicine. It showed that when antibiotics were administered to newborn rats in the immediate aftermath of the injury, it aggravated the cognitive impairment.
"The developing brain is not the same as the fully mature brain. This study suggests that acute interventions targeting the inflammatory cascade may not be a viable strategy for treating traumatic brain injury in infants and young children," noted Ramesh Raghupathi, PhD, a professor of neurobiology and anatomy in the College of Medicine.
What the minocycline drug does is decrease the activation of microglia, the primary immune cells located in the spinal cord and the brain, responsible with protecting the body against foreign pathogens. However, this inhibition of microglia only seems to work in adult brains, while the pediatric model shows a different response,
"There was a lot of cell death, damage and inflammation," noted Raghupathi said, lead author of the study.
The team tested the drug, treating the newborn rats with minocycline, in one daily dosage over a three-day period. The results showed no improvement in the brain activity. Further, the researchers extended the period to nine days instead of just three, and the baby rats showed significant memory issues as well as complementary behavioral problems.
The researchers attributed this result to the role microglia plays in brain development, cleaning the brain of debris and dead neurons as to make room for the functional neurons left to work under normal conditions. By inhibiting this function inside the brains of newborns, the normal process of brain maturation is negatively affected, and cognitive functions can suffer long-term impairment.
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"Whereas injury-induced spatial learning deficits remained unaffected by minocycline treatment, memory deficits appeared to be significantly worse. Sex had minimal effects on either injury-induced alterations or the efficacy of minocycline treatment. Collectively, these data demonstrate the differential effects of minocycline in the immature brain following impact trauma and suggest that minocycline may not be an effective therapeutic strategy for TBI in the immature brain," noted the research.
In the following researches, the scientists will administer the treatment after three or four weeks, as opposed to the 11-days old rats used in the current research, to evaluate the effects. More time for the brain development process could make the difference between a positive and a negative outcome of the treatment, according to the researchers, who wish to establish the age from when on the treatment doesn't cause further cognitive and behavioral impairment, with as much precision as possible.