Hippocampal-prefrontal cortical interactions and neural representations of memory

The ability to store memories and access past experiences when making decisions in the present is fundamental to cognition. The hippocampus is critical for these processes and has been a primary site of investigation in the learning and memory field for the last several decades. However, it is also clear that the hippocampus must work in concert with cortical brain regions to store and recall memories. Findings that demonstrate the necessity of hippocampal-medial prefrontal cortex (mPFC) communication in these processes, as well as findings that link the mPFC to memory storage, retrieval, and decision-making, have contributed to this growing area of study. Here, we review our current understanding of three questions related to this communication. What information is represented in the hippocampus and the mPFC? What are the underlying neural activity patterns and brain states that facilitate communication of those representations? What impact do these patterns have on the ability to learn and remember in new and familiar settings? We highlight evidence for bidirectional communication both during and after experience, and we discuss areas of active investigation to further uncover the role of bidirectional hippocampal-cortical interactions in the formation and maintenance of neural representations of memory.