The KCl-cotransporter KCC2 linked to epilepsy.

In the mature brain, the neurotransmitter GABA can cause a postsynaptic hyperpolarization via activation of chloride permeant GABAA receptor channels. This hyperpolarizing response critically depends on chloride extrusion via the KCl-cotransporter KCC2 [1]. Its knockdown in mice impairs synaptic inhibition by changing the electrochemical potential for chloride and thus increases neuronal excitability [2,3]. Two independent groups provide first evidence now, published in EMBO reports, that rare variants of KCC2 confer an increased risk of epilepsy in men [4,5].