Discovery of memory switch in the brain opens new avenues for dementia therapies

"Why do patients with dementia or cognitive decline remain stuck in past memories?" KAIST researchers have identified, for the first time in the world, the existence of a "neural switch" in the brain that selectively retrieves the most recent memories. This study reveals the principle by which the brain selects necessary information between past memories and new memories, presenting new possibilities for future treatments for memory decline and reduced cognitive flexibility.

KAIST announced on the 17th of May that a research team led by Professor Jin-Hee Han of the Department of Biological Sciences has discovered, for the first time in the world, that a specific neural circuit connecting the medial septum (MS, a brain region that regulates memory and learning) and the medial entorhinal cortex (MEC, a brain region connected to the hippocampus that processes memory information) switches between past and recent memories and plays a key role in selecting up-to-date information appropriate for the situation.

We live by updating our memories through new experiences every day. For example, if the restaurant we visited today was more satisfying than the one we visited yesterday, the brain modifies the existing memory to reflect the new information. In this way, the ability to select necessary information between past and present memories is central to higher cognitive functions such as decision-making, problem-solving, future prediction, and logical reasoning. However, the principle by which the brain distinguishes and switches between memories has long remained unknown.

The research team focused on the medial septum, located deep within the brain. The medial septum regulates the activity rhythms of the hippocampus and acts as a "conductor" that helps the brain effectively store and retrieve information.