Unlocking the secrets of remote memories: dissecting the cortico-hippocampal engram

Every day we form memories based on experience.

These memories undergo a selective process, during which some become long-lasting memories while others fade away.Memory age can be distinguished based on the neuronal systems engaged during different stages: recently acquired detailed memories rely on the hippocampus (especially CA1),while remotely acquired, more generalised memories depend on cortical activation(specifically the anterior cingulate cortex, aCC).

However, our understanding of how certain information from the original event is selected to migrate from one region to the other, while other is lost, remains limited.We aim to explore whether these two regions attend to different information during memory acquisition.

To accomplish this, we will employ FliCRE, an innovative optogenetic tool that offers precise temporal control over the tagging and manipulation of cells through both calcium signalling and light activation.

This groundbreaking technology allows us to attain an unprecedented level of temporal precision, enabling differential labelling of cells that encode distinct information, such as when a mouse is exploring an environment versus experiencing a footshock or freezing.By tagging and manipulating these diverse populations in CA1 and aCC, we will track their recruitment at different time points.

This investigation seeks to shed light on why memory age influences our perception of the original experience differently.

By understanding the underlying neuronal mechanisms, we may find ways to reverse this effect, offering a potential approach to help treat maladaptive memories. Our research holds promise in unravelling the complexities of consolidation and its implications for memory therapies.