Epilepsy cured in rats using 'calm down' genes
UK researchers have for the first time found that adding "calm down" genes to hyperactive brain cells can completely cure epilepsy in rats.
They hope their approach, which used a virus to insert the new genes into a small number of neurons, could help people who cannot control their seizures with drugs.
About 50 million people have epilepsy worldwide, but drugs do not work for up to 30 percent of them. The alternatives include surgery to remove the part of the brain that triggers a fit or to use electrical stimulation.
The brain is alive with electrical communication with individual neurons primed to fire off new messages. However, if a group of neurons become too excited they can throw the whole system into chaos leading to an epileptic seizure.
Researchers at University College London have developed two ways of manipulating the behaviour of individual cells inside the brain in order to prevent those seizures.
In both methods, a virus is injected into the brain to add tiny sections of DNA to the genetic code of just a few thousand neurons.
One method boosts the brain cells' natural levels of inhibition in order to calm them down. The lentivirus used in this study should insert genes into a set, safe, piece of the genome.
Researcher Dr Robert Wyke said it looked like "it's going to be a safe thing".
After a fortnight the number of seizures dropped dramatically and the mice were "effectively cured" within a month.
"It's the first time a gene therapy has been used to completely stop these seizures. Obviously we're very hopeful for this. Drugs haven't done anything for epilepsy in the last 20 to 30 years, just less side effects. There's a real need for a new therapy, we've very excited about this," one of the researchers, Dr Robert Wyke, told the BBC.
The other technique harnessed a gene from algae, which can be controlled by light. After the therapy the function of the neurons did not change until a light was shined on them with an implanted laser. The light prevented the neurons from firing, preventing a seizure.
The researchers think this method could work in a similar way to an implanted defibrillator, which is used to control an irregular heartbeat.
But they noted that more testing of the epilepsy gene therapies would be needed before it could be used in patients.
The study was published in the journal Science Translation Medicine.