A team of neuroscientists at Georgetown University Medical Center have found, in animal models, that they can “switch off” epileptic seizures. The findings provide the first evidence that while different types of seizures start in varied areas of the brain, they all can be controlled by targeting a very small set of neurons in the brain or their tendril-like neuronal axons.
Zeroing in on specific neurons suggests that treatment for epilepsy can be improved, researchers say. For example, the deep brain stimulation used today could be minutely targeted at the cell body of these neurons or at the areas their axons touch, depending on the type of seizure, says the study’s senior investigator, Patrick A. Forcelli, Ph.D., an assistant professor in neuroscience and in pharmacology and physiology at Georgetown.
“We have found a major choke point in epilepsy circuits in rat brains that we believe can be harnessed to disrupt the onset of seizures or to stop their propagation within the brain,” he says. “Circuit-based therapy for people will help offset the known side effects that come with drug therapy and other techniques.”
Researchers have known for about 30 years that while inhibiting a certain area of the brain, the substantia nigra pars recticulata (SNpr) can help stop a seizure, the circuits by which the SNpr controls a seizure have remained unclear. The SNpr is a small area deep within the brain. “It is usually thought to be involved in movement and movement disorders,” says Forcelli. “We knew targeting SNpr can stop a seizure, but we didn’t know how. Neurons in this area have axonal projections that go to many different parts in the brain.”