MECII-originating type 2 dentate spikes (DSM) promote dominance of CA1 slow (∼40-Hz) over mid-frequency (∼80-Hz) gamma oscillations when CA1 represents non-local recollections. Dvorak et al. show that DSM coordinates cofiring within DG, CA3, and CA1 networks and optimizes discharge timing between DG and CA1 for information transfer during memory recall.