How groups of neurons support the formation of memories

Key Points:

• Researchers from PSL Research University, St Jude's Children's Research Hospital, and Princeton University studied how groups of neurons in the CA1 region of the hippocampus contribute to memory formation in mice, finding distinct neuron groups active at different learning phases encoding separate aspects of experiences.
• Using advanced techniques like FLiCRE and calcium imaging, the team identified specific neurons that form engrams—physical changes in the brain that store memories—and demonstrated that only a select subset of neurons is critical for encoding fearful memories.
• The study highlights memory formation as a highly selective process, with many neurons active during experiences but only some contributing to long-term memory storage, challenging previous views of memory as a static snapshot.
• These findings provide new insights into the neural basis of associative fear learning and have potential implications for understanding psychiatric disorders such as anxiety and PTSD, where maladaptive fear associations play a key role.
• Future research will focus on how these neuron ensembles change over time and whether certain molecular or connectivity features make them essential for memory formation, potentially guiding new treatments for neuropsychiatric conditions.