What do zebrafish and antihistamine have in common? Surprisingly, it’s epilepsy! According to a report on the Nature website, scientists have found that seizures in zebrafish can be controlled by giving them clemizole, an antihistamine drug that’s been around since the 1950s.
The fish all had the fish equivalent of Dravet syndrome. Dravet syndrome is a rare condition, starting in infancy, characterised by difficult to control seizures. Seizures can sometimes happen hundreds of times a day. According to the report, scientists were testing 320 different compounds on the fish. The scientists say they are using zebrafish more and more instead of testing on animals like rats or mice. They discovered that clemizole worked to reduce seizure activity, although they don’t know why.
It is well known that some antihistamines can sometimes make seizures worse, so the scientists were surprised: “This finding was completely unexpected. Based on what is known about clemizole, we did not predict that it would have anti-epileptic effects,” said head scientist, Scott Baraban.
Why clemizole works to control seizures in these fish is not known. But the scientists tested 10 other antihistamines and none of them blocked seizures in the same way.
The scientists, based at the University of California in San Francisco, US, are continuing their investigations. We will report any further developments here.