‘Molecular madness’ in brain after blast injury

U. PITTSBURGH (US) — Exposure to a blast can cause changes in the brain that resemble patterns seen in Alzheimer’s disease.

Blast-induced traumatic brain injury (TBI) has become an important issue in combat casualty care. In many cases of mild TBI, MRI scans and other conventional imaging technology don’t show overt damage.

“Our research reveals that despite the lack of a lot of obvious neuronal death, there is a lot of molecular madness going on in the brain after a blast exposure,” says Patrick Kochanek, professor and vice chair of critical care medicine at the University of Pittsburgh. “Even subtle injuries resulted in significant alterations of brain chemistry.”

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Researchers developed a rat model to examine whether mild blast exposure in a device called a shock tube caused any changes in the brain even if there was no indication of direct cell death, such as bleeding. Brain tissues of rats exposed to blast and to a sham procedure were tested two and 24 hours after the injury.

As reported in the Journal of Neurotrauma, gene activity patterns which shifted over time resembled patterns seen in neurodegenerative diseases, particularly Alzheimer’s. Markers of inflammation and oxidative stress, which reflects disruptions of cell signaling, were elevated, but there was no indication of energy failure that would be seen with poor tissue oxygenation.

“It appears that although the neurons don’t die after a mild injury, they do sustain damage,” Kochanek says. “It remains to be seen what multiple exposures, meaning repeat concussions, do to the brain over the long term.”

The Defense Advanced Research Projects Agency funded the project.

Source: University of Pittsburgh