Many patients suffer from epilepsy that cannot be controlled by current medications. Surgical removal of epileptogenic brain regions is effective in only about half of cases, and not all patients are eligible for the procedure. For these individuals, therapeutic options remain severely limited. Researchers from the Paris Brain Institute and the Institut du Fer à Moulin in Paris have now taken an important step forward: they have identified two molecules capable of reducing seizure frequency by targeting a mechanism that has so far received little attention. Their findings are published in Proceedings of the National Academy of Sciences.
For the brain to function normally, it must continuously regulate its electrical activity. One of the key mechanisms involved is GABAergic signaling, a natural inhibitory system that controls neuronal activity and prevents the electrical bursts that characterize epileptic seizures. This braking system depends on a delicate balance: the concentration of chloride inside neurons.
An ion transporter known as KCC2 is responsible for removing excess chloride from nerve cells. When it functions poorly—as observed in many neurological disorders, including mesial temporal lobe epilepsy, the most common form of focal epilepsy in adults—chloride accumulates inside neurons. As a result, GABAergic signals, instead of inhibiting neuronal activity, can paradoxically excite it.
