In addition to theta, various findings suggest that coupling between regions during SWRs may have a distinct role in memory-guided behavior. Hippocampal reactivation during awake SWRs is known to contribute to learning [56], with a proposed role in memory consolidation and retrieval [7,54]. Critically, awake SWRs are up-regulated by both novelty and reward, suggesting a role in memory formation, possibly by establishing spatial cognitive maps and linking behavioral history with reward [42,45,56,68,69]. In addition, SWRs continue to occur after learning, and have thus been proposed to also play a role in planning and prospective decision making [46,55]. These various functions also involve the prefrontal cortex, and the recent finding of coordinated reactivation in hippocampal-prefrontal ensembles during SWRs points towards specific mechanisms for these functions [31]. Since both hippocampal SWRs and theta sequences have been implicated in future memory-guided choices, it will be crucial to investigate how the two interaction modes, coordinated hippocampal-PFC SWR reactivation and theta coherence, change over the course of learning, as well as their variability during trial-by-trial performance of memory-guided decisions. This may potentially reveal crucial relationships between these network patterns on different timescales.
