KAIST researchers have identified a neural circuit in the brain that acts as a switch, selectively retrieving recent memories over past ones.
The study, published in Nature Neuroscience on April 29, 2024, focused on the medial septum (MS) and its connection to the medial entorhinal cortex (MEC).
Key Findings
- The MS-MEC circuit, when active, enables the brain to recall recent memories.
- Artificially blocking this circuit caused experimental animals to revert to past behavioral patterns.
- Hippocampal neural activity also shifted to a past state when the circuit was blocked.
- The brain's "online" theta-wave state, associated with active information processing, correlated with better recall of recent memories; frequent switching between online and offline states reduced retrieval ability.
Implications
This research provides a mechanism for how the brain updates memories with new information while preserving older ones. The authors suggest it may lead to therapies for memory decline in dementia and Alzheimer's disease, where patients often dwell on past memories.
Study Details
The study was led by Professor Jin-Hee Han at KAIST's Department of Biological Sciences. First author Dr. Mujun Kim and co-authors include doctoral students Boin Suh, Sunhoi So, Jung Wook Choi, Jaemin Hwang, and Juhee Park. Funding was provided by the National Research Foundation of Korea, Samsung Science and Technology Foundation, and KAIST Jang Young Sil Fellow Program.
"This research provides a mechanism for how the brain updates memories with new information while preserving older ones."