Limitless: How long-term memories are erased and how to stop it
Currently, neuroscientists think our brain has about enough storage space to hold the entire internet. That’s a lot of space, about a petabyte in fact — if we are to believe this estimate. So, what did you read in the news this day 5 years ago? Don’t worry, I don’t even remember what I had for breakfast this morning and my long-term memory doesn’t fair much better. However, vital information about how the brain erases long-term memories has been uncovered by researchers.
This has important implications for diseases that cause memory loss like Alzheimer’s disease and other types of dementia, not to mention a way to keep track of your pesky keys.
For those of us who suffer from PTSD, this could be the news that we were waiting for because the findings could help scientists to understand why those unwanted memories are so long-lasting while the stuff you really want to remember, lost loved ones, the location of that treasure you buried because you don’t trust banks, or where you really put that left sock — hint, it wasn’t the dryer, I already checked.
We already know a surprising amount about long-term memory storage, like memories are maintained by chemical signalling between brain cells that relies on specialised receptors called AMPA receptors. The more AMPA receptors there are on the surface where brain cells connect, the stronger the memory, which means the easier it is to recall when you really need it.
However, we didn’t know much about how memories are given the boot, or rather forgotten. The team of researchers found that the process of actively wiping memories happens when brain cells remove AMPA receptors from the connections between brain cells, no AMPA receptors no… I forget.
This happens naturally over time and we don’t have a whole lot of control over it, if the memory is not recalled regularly, the AMPA receptors may fall in number. This would theoretically make the memory harder to recall and then eventually the memory is gradually erased. Right now you are probably thinking “stupid brain, what good is that”? Well, researchers also showed that actively forgetting information in this way helps the animals to adapt their behaviour according to their surroundings.
So you can thank evolution for not being able to recall all that information you got at the beginning of your class come final time. Blocking the removal of AMPA receptors with a drug that keeps them at the surface of the cell stopped the natural forgetting of memories, the study found.
Since we love good movies around here — especially as of late — like the movie Limitless, what if we could remember everything? Good question, such a good question, in fact, the researchers wondered the same thing. By blocking the removal of AMPA receptors with a drug that keeps them at the surface of the cell stopped the natural forgetting of memories.
More importantly for those who suffer memory loss — which is the real reason for the research after all. Shame on you for being selfish — drugs that target AMPA receptor removal are already being investigated as potential therapies to help prevent that aforementioned memory loss. The research could be a boon for people living with Alzheimers and dementia, or you know… anyone wanting to not forget all the time.
Unfortunately, and let’s be real, there is always an unfortunately when we are talking about the brain, we probably don’t remember everything for a good reason. In fact, researchers say that active forgetting could be an important facet of learning and memory. Further research is needed to understand what consequences blocking this process could have on the ability to take on new information and retrieve existing memories.
“Our study looks at the biological processes that happen in the brain when we forget something. The next step is to work out why some memories survive whilst others are erased.”
“If we can understand how these memories are protected, it could one-day lead to new therapies that stop or slow pathological memory loss,” said Dr. Oliver Hardt.
Bottom line? Could we live in a world where you never forgot anything? Yeah, maybe one day, but it would probably make living a little harder than you would think and really it could make accurate recall awkward. Think about what happens when you have to sort through all those similar memories of where you parked your car at work.
So maybe you should just look at the lives of Alzheimer’s patients that could be changed by just being able to remember their family or significant others and be happy with that for now.
Migues, P., Liu, L., Archbold, G., Einarsson, E., Wong, J., Bonasia, K., Ko, S., Wang, Y., & Hardt, O. (2016). Blocking Synaptic Removal of GluA2-Containing AMPA Receptors Prevents the Natural Forgetting of Long-Term Memories Journal of Neuroscience, 36 (12), 3481-3494 DOI: 10.1523/JNEUROSCI.3333-15.2016