The expression of receptors designed to respond to specific drugs in the brains of rats has been shown to be effective in reducing seizures in animals with focal epilepsy. The study, reported in this week’s Nature Communications, could prove to be a useful strategy in treating forms of epilepsy that are unresponsive to current forms of treatment.
Seizures that are a result of focal epilepsy are a major cause of neurological disability. Unfortunately, this type of epilepsy is notoriously difficult to treat. Studies have, however, suggested that seizures may be lessened using optogenetics-a process where light reduces the activity of genetically modified neurons in the brain. However, this approach requires invasive implants of light-delivery devices to achieve seizure termination on demand. Using a much less invasive approach, Dimitri Kullmann and colleagues expressed inhibitory designer receptors known as DREADDs in the brains of rats with focal epilepsy and activated these receptors with the drug clozapine-N-oxide. They found that this approach successfully reduced seizure activity over the period that the receptors were active.
Although the authors were not able to match optogenetic approaches in terms of the speed of reduction in seizure activity, they conclude that the relatively non-invasive nature of the approach, and the large areas of brain that can be affected by the drugs, make translation of this method into the clinic much more likely.