Okinawa Institute of Science and Technology study reveals new memory retention mechanism

Researchers studying mice in artificial hibernation have discovered that long-term memory retention may rely on resilient patterns of neural architecture rather than the stability of individual synapses. The study, led by the Okinawa Institute of Science and Technology (OIST) and published in Science, challenges the long-held belief that memory depends on the strength of specific, individual synaptic connections.

During hibernation, the brain undergoes significant remodeling where irrelevant dendritic spines are pruned away. The findings indicate that while many synaptic connections are lost, specific clusters of connected synapses, or engram architecture, are preserved. These preserved structural motifs act as a “core memory trace,” allowing the brain to rebuild functional networks and maintain accurate recall even after losing more than half of its synaptic connections.

Kazumasa Tanaka, PhD, head of OIST’s Memory Research Unit, noted that the study demonstrates the vital importance of engram architecture over individual synaptic strengthening for long-term memory.