OIST Finds Mice Keep Memories After 50% Synapse Loss in Artificial Hibernation

3 articles · Updated · Technology Networks · Aug 18

More than half of hippocampal synapses vanished in artificially hibernating mice, yet long-term memory recall stayed intact and sometimes improved, according to a Science study led by OIST and collaborators.
Roughly 70% of neuronal firing also dropped during hibernation, undermining the long-held view that preserving stronger individual synapses is essential for retaining memories.
CLEM imaging showed memory-linked engrams lost many connections but preserved small clusters of engram-to-engram synapses, pointing to higher-order synaptic architecture rather than spine size as the key memory trace.
The team says the work links memory retention to protected synaptic clusters, though it has not yet proved those clusters directly cause recall and plans to test how the brain preserves them.
Artificial hibernation, first induced in mice in 2020, could become a broader neuroscience tool because the underlying circuitry is conserved across many mammals, including humans.