Brain research suggests memories persist despite significant synapse loss

Researchers at the Okinawa Institute of Science and Technology Graduate University and the University of Tsukuba have discovered that memories may be more resilient to physical changes in the brain than previously understood. By inducing an artificial hibernation-like state in mice, known as Q-neuron-induced hypothermia and hypometabolism (QIH), scientists observed a loss of approximately half of the mice's synapses.

Despite this significant reduction in synaptic connections, the mice were able to retain and resurface memories of previously learned tasks upon awakening. The study suggests that memories do not rely on the preservation of every individual synapse. Instead, certain surviving synapses may act as anchors, forming clusters that preserve memories as patterns of neural activity called engrams, which allow the brain to reconstruct broken circuits.

This finding challenges the traditional view that memory loss is directly tied to the disappearance of specific dendritic spines. While the research utilized an extreme case of artificial hibernation, it provides new insights into how the brain maintains information stability despite the highly plastic nature of neural hardware.