When an animal explores its surroundings, it encodes a spatial representation of the environment by activity patterns of neurons in neuronal circuits of the hippocampus. Encoding of new information in an enriched environment causes substantial re-wiring of GABAergic inhibitory neuronal circuits, characterized by an overall increase of inhibition arriving at the soma of excitatory engram cells. However, it is unknown which structural and functional changes of the inhibitory network are produced by spatial encoding.

We propose that re-wiring of the inhibitory network is a critical feature supporting the maintenance of cell assemblies and the stabilization of the spatial code and that high synchronous events, such as sharp-wave ripples have an essential role in this re-wiring. We aim to address these fundamental questions about the spatial encoding in the inhibitory network by interfering in vivo with the encoding of a spatial task and performing functional and structural analysis of the inhibitory circuits.