A possible link between epileptic seizures and an interaction between immune cells and brain blood vessels is reported online this week in Nature Medicine. The study indicates that these interactions might be a target for the prevention and treatment of epilepsy.
Although epilepsy affects about 1% of the world population, its underlying mechanisms are poorly understood. Gabriela Constantin and colleagues show that seizures induce the expression of adhesion molecules in blood vessels of mice brains, holding immune cells called leukocytes in the circulatory system of the brain. Stopping the interactions of these cells with blood vessels or depleting certain immune cells known as neutrophils markedly reduced seizures.
The authors also found that seizures caused the barrier between the blood and the brain to become leaky, a phenomenon known to enhance the tendency of neurons to become active. However, blocking the binding of leukocytes to brain vessels prevented such a leak, linking leukocyte-blood vessel interactions, damage to the blood-brain barrier and seizure generation. Finally, the team found that leukocytes were more abundant in brains of people with epilepsy than in healthy subjects, a finding consistent with a potential leukocyte involvement in human epilepsy.