Deciphering the Molecular Puzzle of Memory: How Brain Cells Secure Information Across Time.

 

Neuroscientists have unveiled groundbreaking insights into how our brains improve the ability to distinguish between similar experiences. This discovery carries potential implications for treating Alzheimer's and other memory disorders.

Consider moments when you encountered two similar experiences in quick succession. Perhaps attending two holiday parties or giving two work presentations. Initially, confusion may arise, but over time, the ability to differentiate between these experiences strengthens.

Published in Nature Neuroscience on January 19, the research delves into engrams, brain cells storing memory information. Engrams, crucial for memory recall, face disruption leading to amnesia when disturbed.

The study focuses on the consolidation process, occurring in the minutes and hours post-experience. The brain consolidates engrams to store memories. A computational model revealed the dynamic nature of engram populations, with activated cells decreasing over time. This phenomenon is critical for memory discrimination and improves as time elapses.

Experiments with mice supported these findings. Exposure to distinct environments initially resulted in an inability to discriminate between them. However, after a consolidation period, the mice could distinguish and exhibited fear selectively.

Utilizing a light-sensitive technique, the team identified active neurons in the mouse hippocampus during exploration. This allowed tracking of engram cells across experiences and time, correlating their response to memory discrimination.

The research sheds light on memory disorders, emphasizing the importance of understanding early memory formation processes. In Alzheimer's, dysfunction may stem from issues during the crucial period when engrams undergo changes.

Ongoing studies involve mouse models of early Alzheimer's, exploring whether engrams form but fail to stabilize correctly. With increased understanding of engram dynamics, researchers can now investigate gene alterations during decreased engram populations, potentially offering avenues for improving memory performance.

The study, led by Dheeraj S. Roy, was conducted during his tenure as a McGovern Fellow at MIT and Harvard. Co-authors hail from various institutions globally, contributing to a comprehensive exploration of memory dynamics. Funding from diverse sources, including Imperial College London and the Wellcome Trust, supported this groundbreaking research.