Method for Isolating Memory Formation Developed

Reporting in Science, a team at Kyoto University's Akihiro Goto used mouse brains to demonstrate a new neural-optic system to manipulate memories. The technique hinders nerve activity—known as long-term potentiation or LTP—which would otherwise consolidate memory during sleep.

The team illuminated mouse brains to inhibit cofilin, a protein essential for the synapse to function. Initially, the brains were injected with the adeno-associated virus or AAV, which then expresses a fused protein made from cofilin and fluorescent SuperNova. When exposed to light, these proteins release reactive oxygen that deactivates nearby compounds like cofilin.

The occurrence of LTP in the hippocampus, where memories are first stored, was significant. When this area of the brain was irradiated, once immediately after the mouse learns a task and then again during sleep after learning, the memory is lost. "It was surprising that eliminating local LTP by targeted illumination clearly erased memory," lead researcher Akihiro Goto comments.

Hayashi believes that this new technology provides a method for isolating memory formation both temporally and spatially in the brain at the cellular level. Synaptic abnormalities related to LTP are involved in memory and learning disorders like Alzheimer's disease and also psychiatric diseases like schizophrenia. The team concludes, "We expect our method will lead to a range of treatments for mental disorders."