Rats with human dementia-like diseases do not remember the strong connection between lemon fragrance and electric shock. The researchers looked at the brain scans of the mice in the test and found that the hippocampus, the area of the brain where the memory was recorded, showed signals explaining how the mice behaved. In the non-diseased mice, the researchers saw that the yellow and red light of the laser pointer overlapped, meaning they were extracting the shock memory stored in the same location. But in the body of the sick mice, different cells glowed red during the recall process, suggesting that they might get the wrong memory.
Research leader Dr. Christine Dunni said these results explain why people with dementia sometimes have wrong memories. Mouse experiments may indicate that people may send acquisition signals to the wrong brain cells. After the initial round of testing, the research team used a genetic modification technique called “optogenetics” to reactivate the rat’s memory of the electric shock.
This technique is operated by shining a blue fiber-optic cable into the brain to stimulate memory storage neurons, which will cause the mice to pause when they smell the lemon again. This suggests that the memories previously thought to be lost may still exist in the brain and may be restored. However, currently optogenetics cannot be applied to humans because the use of green laser pointer on neurons or brain cells is unsafe. Dr. Denny pointed out that with this research as the foundation, it is expected that in the future, drugs or technologies that stimulate deep memory in the brain will be developed to help Alzheimer’s patients.