‘Remarkable’ discovery upends our understanding of how brains store memories

# Summary

Researchers at the Okinawa Institute of Science and Technology induced artificial hibernation in mice to study how memories persist during extreme brain changes. Mice trained to associate electric shocks with an alcohol-scented chamber retained fearful memories even after hibernation reduced brain activity and disrupted over half of the neural connections encoding that memory. The finding challenges the prevailing theory that memories depend on stable synaptic patterns, suggesting memory storage is more robust than previously understood.

The study examined mice genetically engineered or treated to enter hibernation-like states, then tested whether they retained conditioned fear responses days later. Brain scans confirmed significant alterations in the neural architecture of memory-encoding neurons, yet the mice still displayed the learned behavior. The discovery may eventually inform approaches to preserve or restore memory function in conditions affecting synaptic integrity.