My research topic focuses on hippocampal contribution to neocortical neurodynamics in the process of memory encoding and consolidation. The hippocampal formation (HF) has long been considered an essential brain structure supporting these functions. One prominent view (The Memory Index Theory) holds that the HF generates an ‘index’ for sub-attributes of ‘episodic’ memory, which is distributed among many neocortical modules. The view also suggests that during sleep the HF helps ‘consolidate’ recent episodic memories and extract general (‘semantic’) knowledge. Despite our general understanding of the theory, how exactly the HF index modulates neocortical neurodynamics needs to be experimentally confirmed. I use a combination of behavioral (e.g., environmental enrichment, spatial learning in virtual reality, classical eyeblink conditioning), optical (e.g., voltage-sensitive dye imaging, wide-field calcium imaging), and electrophysiological tools to investigate how the neocortical activity patterns differ between the brain with or without the hippocampus and how the neural patterns relate to behavior.