Flexible modulation of sequence generation in the entorhinal-hippocampal system

Exploration, consolidation and planning depend on the generation of sequential state representations. However, these algorithms require disparate forms of sampling dynamics for optimal performance. We theorize how the brain should adapt internally generated sequences for particular cognitive functions and propose a neural mechanism by which this may be accomplished within the entorhinal-hippocampal circuit. Specifically, we demonstrate that the systematic modulation along the medial entorhinal cortex dorsoventral axis of grid population input into the hippocampus facilitates a flexible generative process that can interpolate between qualitatively distinct regimes of sequential hippocampal reactivations. By relating the emergent hippocampal activity patterns drawn from our model to empirical data, we explain and reconcile a diversity of recently observed, but apparently unrelated, phenomena such as generative cycling, diffusive hippocampal reactivations and jumping trajectory events. McNamee et al. develop a theory of entorhinal-hippocampal processing. Distributed entorhinal input drives hippocampal activity between distinct statistical and dynamical regimes of activity, thereby unifying several empirical observations.

Automated summary

The article discusses how the brain adapts internally generated sequences for cognitive functions and proposes a possible neural mechanism. The study found that systematic modulation along the medial entorhinal cortex dorsoventral axis can facilitate a flexible generative process in the hippocampus.