Cover image: Pictured is a coronal section through the dorsal hippocampus of a transgenic mouse. Using a model in which mice were trained to perform a spatial working-memory task, Christopher J. MacDonald and Susumu Tonegawa examined how neurons in the final output region of the hippocampus (dCA1) coded time and space. One input into this region (dCA2) was selectively inhibited while the mice remained spatially fixed during a 10-second mnemonic delay, which degraded dCA1 time cell coding and impaired subsequent memory-guided choices. However, there was no effect on choice behavior or dCA1 place cell coding when dCA2 inputs were inhibited as the mouse moved through the maze, suggesting that the dCA2 plays a selective role in representing the flow of time in memory. See the article by MacDonald and Tonegawa on page e2020698118. Image credit: Christopher J. MacDonald and Susumu Tonegawa.