Persistent Interruption in Parvalbumin Positive Inhibitory Interneurons: Biophysical and Mathematical Mechanisms.

Persistent activity in neuronal networks is thought to provide a substrate for multiple forms of memory. The architecture of neuronal networks across many brain regions involves a small number of inhibitory neurons that control many principal neurons. We propose that persistent silencing of fast-spiking parvalbumin-expressing inhibitory interneurons (PVINs) can result in persistent activity of principal neurons. We use a mathematical approach and computer simulations to investigate the mechanisms governing persistent interruption of firing in hippocampal and cortical PV-INs. We show how a slowly changing state of a particular ion channel controls the long-lasting silence imposed by persistent interruption. Overall, our results provide a conceptual framework that positions the persistent interruption of PV-INs firing as a potential mechanism for persistent activity in principal cells.