NOMIS researcher Franck Polleux and fellow scientists at Columbia’s Zuckerman Institute have, for the first time, observed how synaptic connections in the brain change during memory formation in living mice. Their study, published in Nature, provides direct evidence supporting the long-standing theory that memories are encoded through synaptic plasticity — the strengthening or weakening of neuronal connections.
Using advanced imaging techniques, the researchers genetically modified hippocampal neurons to fluoresce based on synaptic activity. This allowed them to track which synapses were active and how their strength changed as mice navigated a virtual environment. They discovered that synapses active just before a memory formed were strengthened, while those outside this window weakened.
This finding aligns with a recent model suggesting that a single experience can create a memory, rather than requiring multiple repetitions. Additionally, researchers noted that synaptic changes occurred primarily in certain regions of neurons, hinting at a more complex, subcellular organization of memory formation.
These insights could enhance understanding of learning, memory disorders, and neurodegenerative diseases. By identifying the molecular mechanisms underlying synaptic plasticity, scientists may uncover new approaches to treating memory-related conditions.
Read the Nature publication: Synaptic basis of feature selectivity in hippocampal neurons
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Columbia Zuckerman Institute: New Peek at Connections Between Neurons Shines Light Into Memory Formation
