A group at Kyoto University, RIKEN, and Osaka University have succeeded in developing a method for erasing memory by irradiating it with light, and using it to clarify when and in which cell memory is retained. Announced that it has conducted research for.
Memory is thought to be preserved in the hippocampus for a short period of time and then in the cortex for a long period of time (memory immobilization), but this mechanism has not yet been elucidated.On the other hand, as a phenomenon in cells forming memory, "long-term potentiation of synapses (LTP)", which increases the efficiency of transmission of neural activity between cells, is known. If possible, it will be a hint to clarify the process of memory immobilization.
Therefore, this group has developed a technology to eliminate LTP only at the target location and time using the sea anemone-derived photosensitizing fluorescent protein SuperNova, which has the property of inactivating surrounding proteins when irradiated with light. By fusing SuperNova with a molecule called cofilin, which is important for LTP, and irradiating it with light, cofilin is inactivated and LTP is erased, so only the synapses that caused memory can be erased.
When we tried to detect the time frame in which LTP occurred by this technique, we found that the memory was erased immediately after learning or when the hippocampus of sleeping mice was irradiated with light after learning.It is suggested that gradual LTP occurs in the hippocampus immediately after learning and in sleep thereafter, thereby forming short-term memory.Interestingly, he also found that memorable synapses exist in different parts of the brain immediately after learning, during subsequent sleep, and during sleep the next day.
Furthermore, it was found that LTP induction was observed in the anterior cingulate cortex during sleep the day after learning, and that the memory for immobilization had already begun to transfer to the cortex the day after learning.
It is expected that the technology developed in this research, such as a science fiction movie that erases memory with light, will continue to elucidate many brain functions involved in memory at the cellular level.
Paper information:[Science] Stepwise synaptic plasticity events drive early phase of memory consolidation
