The hypothesis that a single neuronal algorithm serves both to order events and to provide temporal context is also supported by experiments showing that, when the imposed delay between the cue and response is altered, the sequential structure of cell assemblies changes in accordance with the response patterns of place cells during navigation. Although some cells remain anchored to the beginning of the delay, as place cells are anchored to the start box8,86, most neurons form a completely new trajectory, in a manner resembling the remapping of place cells in response to context change93 (Fig. 4c). Keeping track of time by evolving cell assembly sequences at the seconds to minutes timescale may be a general rule in the cerebral cortex, including in the prefrontal95 and retrosplenial96 areas. To bridge longer intervals, further mechanisms may be required97,98.
