HOW DO ANIMALS LINK MULTIPLE EVENTS IN TIME?

Animals exhibit a diverse array of behaviors where they keep track of time. In our study, we have focused on how multiple events are temporally linked. One of the neural mechanisms proposed to keep track of time is the 'time cells (TCs)' in the CA1 region of the hippocampus. In this project, we explore the network dynamics of TCs when animals are presented with multiple time intervals. We modified the classic trace eyeblink conditioning (TEC) task such that a third stimulus was delivered after the US (unconditional stimulus, airpuff), thereby incorporating two time intervals. Adding a third stimulus recruited more TCs depending on its salience. We also found TCs encoding dual time fields, absent in the first TEC task. Tracking over several days revealed that very few cells persisted as TCs, yet they retained their time fields. Our findings showed that TCs are not a product of the learning state but part of internally generated sequences. The results also imply that, although these are internally generated, any new event can modulate them and reset them even, given the salience of the event. Finally, the network state for any given day contributes to the TC emergence than the task itself. Overall, we show some insights into how the TCs remap in the context of multiple events.