When an important paper arrives on your desk, you may decide to file it away. Memory consolidation occurs when memories first form in one section of the brain and subsequently transfer to another for long-term preservation.
Akihiro Goto of Kyoto University utilizes mouse brains to illustrate a new neural-optic system for manipulating memories, which he published in the journal Science. Long-term potentiation, or LTP, is a type of neural activity that would otherwise solidify memory during sleep.
LTP is important for memory formation because it strengthens synapses through brain activity. Examining when and which cells undergo LTP can reveal when and where memories are created in the brain.
Drugs can disrupt LTP, although they have a broad effect and are ineffective at targeting specific brain regions at certain memory consolidation times peri
Looking for inspiration, Goto turned to Hollywood.
“In Men in Black, the agents erase memories with a light flash. We did something similar,” he says with a smile. His team uses light to deactivate proteins essential for LTP.
Co-author Yasunori Hayashi’s team uses white lab coats and safety goggles instead of black suits and shades to illuminate mouse brains in order to suppress cofilin, a protein required for synapse activity.
It was surprising that eliminating local LTP by targeted illumination clearly erased memory.
Akihiro Goto
The brains are first injected with the adeno-associated virus, or AAV, which then expresses a fusion protein made of cofilin and fluorescent SuperNova, which is often employed for gene delivery. When these proteins are exposed to light, they produce reactive oxygen, which deactivates adjacent molecules like cofilin.
It’s significant that LTP occurs in the hippocampus, which is where memories are originally stored. The memory is lost when this part of the brain is irradiated twice: first immediately after the mouse learns a task and again during sleep following learning.
“It was surprising that eliminating local LTP by targeted illumination clearly erased memory,” Goto comments.
Hayashi believes that this new technology may be used to isolate memory development in the brain at the cellular level, both chronologically and spatially.
Memory and learning disorders like Alzheimer’s disease, as well as psychiatric conditions like schizophrenia, are linked to synaptic anomalies caused by LTP.
Hayashi concludes, “We expect our method will lead to a range of treatments for mental disorders.”
