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Marine Epilepsy

March 22, 2010

Algal blooms can cause epileptic symptoms in sea lions and other marine mammals.


Seizures from the sea. I’m Bob Hirshon and this is Science Update.

You usually see California sea lions basking themselves in coastal areas, but they’ve been reported in some very unexpected places.

Walking along on a freeway, 100 miles inland in an artichoke field. Another one was reported to be in a used car sales lot.
That’s NOAA physiologist John Ramsdell. His lab has determined that the weird behavior is probably the result of epilepsy, brought on by exposure to a chemical called domoic acid, which is formed by periodic algal blooms off the coast of California. He says domoic acid causes neurons in the brain to fire for an abnormally long time.

So instead of giving a spark of excitation, they give a spark that spreads like wildfire to cause seizures.

Ramsdell says the poison might cause epileptic symptoms in other animals, including humans, as well. I’m Bob Hirshon for AAAS, the Science Society.