In the dentate gyrus, a small subset of the granule cell population takes part in an engram encoding the spatial features of the environment. Formation of this neuronal code depends on the activity-dependent changes in synaptic strength after synchronous activation of excitatory inputs that generate local dendritic activity, a process that is under tight inhibitory control.

Using a combination of quantitative ultrastructural, electrophysiological and computational approaches we will study the cellular and molecular mechanisms by which dendritic excitatory and inhibitory synaptic inputs control the sparsity of granule cells engaged in the encoding of contextual information.