Lost Memory Can Be Restored Thanks to Brain's Features
Scientists at the Okinawa Institute of Science and Technology have found that the brain can restore lost memories even after losing more than half of its synaptic connections. In an experiment with mice placed in a state similar to hibernation, fear memory persisted five days after waking. Some synapses remained clustered, while others recovered within a day. Researchers suggest that stable clusters store information, while others provide access to it. The results may help treat memory disorders, but are currently based only on mouse experiments.
Scientists at the Okinawa Institute of Science and Technology, led by Kazumasa Tanaka, have discovered that the brain can restore lost memories even after significant loss of synaptic connections. In the experiment, mice formed a fear memory of a specific odor, after which some animals were placed in an artificially induced state similar to hibernation for two days. Five days after emerging from this state, the mice still showed fear when exposed to the familiar odor, despite having less than half of the synaptic connections on engram neurons in the hippocampus. During brain reorganization, some synapses remained clustered and preserved, while others temporarily disappeared and then recovered within a day after waking. According to the scientists, this may indicate a division of functions: stable clusters of synapses may store the information itself, while other connections provide access to the memory. Steve Ramirez from Boston University, who was not involved in the study, noted that the results may indicate greater resilience of memories than previously thought. The researchers believe that these data help deepen understanding of long-term memory mechanisms and may eventually contribute to developing new approaches to treating memory disorders. However, the conclusions are based only on mouse experiments, so it is premature to talk about applying this approach to humans.