Overview
- Researchers induced a torpor-like state in mice by activating a neuronal switch and observed rapid hippocampal synapse pruning with more than half of synapses lost within a day while learned behaviors remained intact.
- A control experiment that used long-term anesthesia plus a molecule that blocks synaptic strengthening produced similar synapse loss but caused the animals to lose the memories.
- Detailed imaging showed that certain clustered groups of dendritic spines and hub-like outgoing connections were preferentially spared during hibernation and correlated with preserved memory performance.
- The findings challenge the idea that long-term memory depends only on individually strengthened synapses and suggest network topology, not just synapse strength, helps stabilize stored information.
- The team plans molecular profiling and targeted manipulations of the resilient clusters to test causality, the work was published in Science from a mouse model, and application to humans remains uncertain.