Parvalbumin interneurons provide grid cell–driven recurrent inhibition in the medial entorhinal cortex

Does the spatial tuning of grid cells in the medial entorhinal cortex (MEC) require spatially tuned inhibition? Buetfering and colleagues recorded optogenetically identified parvalbumin (PV) interneurons in the mouse MEC during foraging and found that they were broadly tuned. Moreover, the authors found that stimulating PV cells suppressed firing in grid and head-direction cells but did not alter the spatial tuning of these cells.