Conditional upregulation of KCC2 selectively enhances neuronal inhibition during seizures

Efficacious neuronal inhibition is sustained by the neuronal K+Cl- co-transporter KCC2, and loss of KCC2 function through injury or mutation is associated with altered GABAergic signalling and neuronal seizures. Here we report a transgenic mouse with conditional KCC2 overexpression that results in increased membrane transport function. Increased KCC2 has little impact on behavioural and in vitro assays of neuronal excitability and GABAA receptor responses under resting conditions. In contrast, increased KCC2 imparts resistance to seizure-like neuronal activity in hippocampal slices and prevents the progression of mice into behavioural status epilepticus following multiple kainic acid doses. Our results demonstrate a transgenic mouse to facilitate investigations into the role of KCC2 in brain function, and provide a proof of principle that targeting KCC2 may be an effective way to selectively enhance neuronal inhibition to mitigate against diseases that involve an imbalance between excitation and inhibition.