KCC2 overexpression prevents the paradoxical seizure-promoting action of somatic inhibition

Abstract

Previous studies have highlighted a paradoxical role of perisomatic-targeting parvalbumin-positive (PV+) interneurons in ictogenesis. Here, authors used an acute in vivo model of focal cortical seizures in awake behaving mice to show that photo-depolarization of PV+ interneurons rapidly switches from an anti-ictal to a pro-ictal effect within a few seconds of seizure initiation, and that this switch can be prevented by overexpression of the neuronal potassium-chloride co-transporter KCC2 in principal cortical neurons.