Lateral Entorhinal Cortex Identified as Key Brain Region for Managing Memory Interference
Researchers used chemogenetics to show that the lateral entorhinal cortex (LEC) in the brain plays a crucial role in retrieving old, irrelevant memories that help prevent interference with new learning. When the LEC was inhibited during memory retrieval, animals showed increased conditioned fear responses to pre-exposed stimuli, suggesting the region normally suppresses competing old memories. This finding may explain why memory interference increases with age, as LEC function declines over time.
A new study published on bioRxiv demonstrates that the lateral entorhinal cortex supports the retrieval of prior inconsequential memories that compete with newer associations during learning. Using chemogenetic techniques to temporarily inhibit excitatory neurons in the LEC during a latent inhibition task—where prior exposure to a stimulus reduces conditioned responses when that stimulus is later paired with an outcome—researchers found that LEC inhibition selectively impaired this interference-suppression mechanism. Importantly, LEC inhibition did not affect retrieval of new tone-shock associations, indicating the region's specific role in accessing old, irrelevant memories rather than general memory retrieval. The findings suggest a mechanistic explanation for age-related increases in memory interference, since LEC function is known to decline with aging. This work advances understanding of how the hippocampal-entorhinal system manages competing memories and may have implications for cognitive aging and memory disorders.
Limitations & open questions
The study does not discuss potential therapeutic applications or whether findings in animal models translate to human memory interference. Additionally, the mechanisms by which age-related LEC decline specifically leads to increased interference, and whether interventions targeting LEC function could mitigate age-related memory problems, remain open questions.
What different sources said
- bioRxivCenter
Dissecting the Role of the Lateral Entorhinal Cortex in Memory Interference
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