In addition to forgetting things, many people often have false memories, memories of things that never actually happened. False memory implantation often happens as a result of suggestion, but it can also be manipulated with specific technologies including gene editing and brain stimulation.
Most recently, researchers were the first to implant these false memories is sleeping mice. Additionally, these memories persisted after the animal woke up and affected the mouse’s behavior. To implant the memories, researchers targeted the medial forebrain bundle (MFB), part of the reward system, and the hippocampus which is important for memory. Within the hippocampus, they focused on place cells which are nerves that activate when the animal is in a specific location, a function important for spatial navigation
These place cells can be identified in an individual mouse by recording neural activity as the mouse enters various areas in an environment and noting which areas in the brain are activated in certain areas of the environment. Once the cells were identified, researchers stimulated the MFB while the mouse was awake and the place cells were active. This stimulation of reward circuitry while in a certain area produces a false positive association between a particular area in the environment and a reward, causing these mice to spend significantly longer in this particular area than randomly stimulated control mice.
During sleep, the neurons in the hippocampus replays the waking experiences, researchers continued to monitor brain activity while the mice were sleeping. Whenever the place cell of interest fired, a computer automatically stimulated the MFB. Once awake, these animals spent up to 5 times longer in the area that corresponded to the place cell that had been paired with MFP stimulation compared to randomly stimulated mice showing that the specific MFP stimulated mice has a conscious memory of a reward in this location.
These results indicate a successful technique for implanting false memories in mice, which could play a role in better understanding certain memory problems, mental illnesses involving memory, and ways to make eye-witness testimony more reliable
3 thoughts on “False memories implanted in sleeping mice”
I have recently learned about brain stimulation of reward and knew that brain stimulation is done when the animal is conscious. But I didn’t know that you can stimulate brain of a sleeping animal. It was also interesting to read that stimulating brain of a sleeping animal has greater effect than stimulating brain of a conscious animal.
Thanks for posting! I enjoyed reading your post and the super cute picture of a sleeping mice!
I did not realize that it has become possible to implant a memory or that the process would require the animal to be sleeping during the process. I thought that this post was very interesting and informative. I really enjoyed reading!
This idea of planting false memories is somewhat worrisome and reminiscent of tracker jacker venom in the Hunger Games series. On a less sci-fi note, it made me think about how dreams affect your memory. Sometimes you wake up from a particularly poignant dream and are unsure whether or not your dreamed experience actually happened or not. What is the difference between brain activity when you dream an experience and when your brain is stimulated to create a “new memory?” Is it possible that dreams are just a weaker version of this stimulation?
Thus, would it be possible to augment brain activity in a sleeping person? If so, would it be possible to increase the reward mechanism for certain behaviors to the point where the behaviors increase when the subject is awake? Kind of a scary thought, but also potentially useful when thinking about treatment for mental disorders.