On a shelf at the Center for Marine Science, dozens of clear glass jugs are filled with greenish water, home to a tiny marine algae known as “dinoflagellate Karenia brevis.” The organism is the same type present in the dangerous algal blooms known as “red tides,” which produce toxins that kill fish, make shellfish dangerous to eat and cause respiratory problems for humans, among other things.
But the algae being grown at the University of North Carolina Wilmington facility will be used for a starkly different purpose — improving the lives of people who have had strokes or traumatic brain injuries.
“There is a brevetoxin that’s found in Florida red tides, which in large quantities is toxic to humans,” said Dan Baden, director of the Center for Marine Science. “But any drug in large amounts is toxic. What we are doing is finally determining the concentration at which the brevetoxin can exert positive therapeutic effects rather than the overwhelming toxic effects.
A team of researchers, led by Dr. Thomas Murray of the Creighton University School of Medicine, published its recent findings in the Nov. 12 online edition of the journal Proceedings of the National Academy of Sciences. Other researchers included staff from UNCW and the Scripps Institution of Oceanography.
Currently, researchers are attempting to discover the level of toxin that can be used to regenerate nerve function in the brain, particularly for patients who have suffered strokes.
Strokes occur when a clot restricts blood flow to a specific area of the brain, damaging nerve function. That disruption can translate into numbness, difficulty walking or speaking and a host of other side effects.
“You can have a disruption of the chemical communication between two nerves,” Baden said. “One end of the nerve, the pre-end, releases chemicals that diffuse across to the post-end, and that’s how nerves communicate. If that’s disrupted, functions cease to work properly, resulting in paralysis, memory loss, and the other things that can happen due to a stroke.”
The resulting dead tissue can’t be brought back to life, but research suggests that with the correct amount of brevetoxin, the brain can be trained to redirect those nerve impulses to other living cells.
“The toxins open little doors called ion channels, which are responsible for nerve transmissions,” Baden said. “They open and close in a specific fashion that allows the nerve to function and fire. What brevetoxins do in high concentration is cause all those little doors to open, and that means all the nerves fire at the same time. It’s lethal.”
But at the correct concentration, the toxin can help the nerves to function normally, he said.
“You back off on the dose of a toxin that you give to a nerve cell, and instead of all the nerve channels opening at the same time, they function a little bit better,” he said. “By responding to the chemical, they open to an extent that they mimic what would normally happen.”
Research is ongoing, and the next step involves focusing on specific molecules to help determine which ones affect individual nerve functions. Ultimately, the goal is to help develop a medication, but that’s probably at least a decade away, Baden said.
“For me, it’s kind of bittersweet. You make the discovery and we’re really excited about it and the first thing that happens is people call and say, ‘I have a brother who’s had a stroke. Can you help him?’” he said. “All of this basic and applied research that we do actually does benefit mankind ultimately. These are long-term views that we have to have.”