Reflection of Hippocampal Cell Ensemble Activation Patterns in Model-Based Behavior in Rodents

Abstract

Although much is known about the role of the hippocampus cell ensemble activation patterns in supporting the navigation and localization of rodents, there has only been limited data on how the same patterns reflect and support model-based planning, or planning based on an internal model of the rodent’s environment. This study therefore investigated the existence of model-based planning in rodents using a specialized spatial odorant-memory task and the corresponding hippocampal cell ensemble activation patterns. By performing this task, it was possible to theoretically differentiate between model-based and other behaviors while hippocampal cell ensemble activations were measured using calcium imaging. The results indicate that although there is evidence of model-based planning in rodents, it is utilized with other behaviors for the spatial odorant-memory task. Such findings suggest that to fully capture the relationship between the hippocampal cell ensemble activation and model-based behavior, model-based behavior’s definition should be improved and more of their corresponding neural data must be collected.