July 26, 2013
A Mousey Matrix
As a fan of psychology and almost all things related, one thing that has always piqued my interest is the notion of repressed memories. I can’t tell you how many times I’ve visited with family members on a lazy Sunday, and how many arguments are sparked by someone recalling an event, and someone else swearing that event never happened. Having watched these familial events, as well as others in similar situations, I began to wonder if it’s possible to repress memories; is it also possible to implant them? And if so, how easily can this be done? Well, my friends, buckle your seat belts, because according to a collaborative study between scientists in Japan and Cambridge, this is no longer the stuff of imaginations or freaky fiction; this is a reality.
Or at least in mice. Susumu Tonegawa, the memory study’s senior author, told CNN that scientists took mice and placed them in a box. This box brought about symptoms of distress in the mice, since they recalled their tiny sensitive feet being shocked in the cube. However, in reality, the mice were never actually shocked. Instead, prior to being placed in the box of expected, but non-existent, pain, scientists used optogenetic techniques to manipulate the mice’s brain cells into forming memories of being shocked inside the box. In. Sane.
What is optogenetics you ask? Well, opto means light, and, genetics means genetics, simply put. Mikhail Shapiro, neuroengineer at the University of California at Berkeley explains further. “Optogenetics refers to controlling neurons with light. Although this usually means you have to stick an optical fiber into the part of the brain you are interested in controlling, you get incredible precision (on the timescale of milliseconds), so you can study causal relationships between activity in different parts of the brain and behavior.”
So, for the mice in this specific study, researchers initially placed the mice in a safe box A and labelled the cells responsible for creating the “safe” memory with a light sensitive protein called channelrhodopsin. The following day, mice were placed into an “unsafe” box B where they were slightly shocked with electricity. At the exact moment that the mice were shocked, scientists reactivated the “safe” memory from box A with light, which caused the mice to associate the shocks from box B with the memory of the safe box A. This process was repeated and eventually the light was no longer used to cause the mice to “remember” being shocked once placed in safe box A; the mice “remembered” on their own what happened there.
But, what are the implications for this in memory research? It’s an entirely fascinating and slightly frightening subject to ponder. If you can create an unpleasant memory, could you also create a lovely recollection to replace a negative one? Or simply, just block out a negative memory completely? A sort of man made repression, if you will. If this were to be something readily available for humans to try, would people be lining up to have memory “cosmetic” surgery? While researchers have no plans, most likely due to ethical and legal reasons, on replicating these memory experiments in humans, this could be a very promising area of research for patients who suffer from mental disorders, such as schizophrenia, that cause them to have hallucinations and false memories.
Image Credit: Thinkstock.com