How a gene defect in dogs could help treat epilepsy in humans
'This gene hasn’t been associated with epilepsy before in humans or dogs,' researcher says
The discovery of a gene in Rhodesian ridgebacks that is linked to epilepsy could also impact how the disorder is treated in some human patients.
An international team, which included University of Guelph Ontario Veterinary College professor Dr. Fiona James as a co-investigator, discovered a defect in the gene, DIRAS1, causes epileptic seizures in dogs.
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"This gene hasn't been associated with epilepsy before in humans or dogs," James said in an interview on CBC K-W's The Morning Edition with host Craig Norris.
"So we have an exciting new pathway to explore in terms of new treatments and new ways of investigating it."
Listen to the interview:
Backpacks track brainwaves
Researchers from the University of Helsinki in Finland and Ludwig Maximilian University of Munich in Germany led the study, which attached backpacks to dogs that were known to have jerking motions when drowsy, sleeping or just standing quietly.
In the past, to record brainwaves, researchers had to confine dogs or use drugs to have the animal go to sleep.
The backpacks – which James developed before this study – allowed the researchers to attach electrodes to the dogs' heads while the dogs were awake, and then the dogs were able to roam free, which gave them a better idea of what was regularly happening in the brain, James said.
Once the backpack and electrodes were attached, they would watch as the dog settled down.
Like a stadium of people
James likened watching the brainwaves of a dog having an epileptic seizure to a stadium full of people.
The brain is the stadium and all of the neurons are people.
If someone puts microphones into the stadium, there's a hum from the crowd. The electrodes on the dog's head are those microphones.
"A normal crowd doesn't say one word all together unless they're really stoked and something special's happening," James said.
"What happens when there's a seizure is the whole crowd – all the neurons – are saying the same thing at once, or at least a good portion of them are saying the same thing at once. And that's a really unusual and rare event."
Research 'meaningful' for many species
The study looked at more than 600 Rhodesian ridgebacks as well as 1,000 epileptic dogs in other breeds.
The epilepsy linked to this gene is canine myoclonic epilepsy, which Helsinki research Hannes Lohi said resembles human juvenile myoclonic syndrome.
"The study has therefore meaningful implications for epilepsy research across species," he said in a release about the study.
"Myoclonic epilepsies are one of the most common forms of epilepsy in humans and the canine findings will not only help in diagnostics but also provide a novel entry point to understand the pathophysiology of the disease."
It is estimated 260,000 Canadians have some form of epilepsy.
James said the seizures begin at about the same age in the dogs as well as people, and both the dogs and humans showed similar clinical signs of the disorder and responded to drugs similarly.
The study was published in Proceedings of the National Academy of Sciences on Feb. 20.