Emergence of preconfigured and plastic time-compressed sequences in early postnatal development

Memory capabilities develop with age During memory formation, time-compressed neuronal sequences underlie consolidation as well as encoding of novel information. Such memory traces are largely contributed by a selection of preconfigured neuronal patterns. However, when and how these preconfigured patterns first emerge in the hippocampus is unknown. Farooq and Dragoi identified an age-dependent development of network preconfiguration into trajectory-like sequences. This preconfiguration was expressed spontaneously during sleep and emerged from the assembly of persistent, location-depicting ensembles, largely controlled by intrinsic developmental programs. Thus, the compressed binding of adjacent locations into spatial trajectories during navigation and their experience-dependent replay emerge in coordination from spontaneous preconfigured sequences. Science , this issue p.168