THE COLLEGE HILL INDEPENDENT


HICKORY DICKORY DOCK, THE MOUSE RE-WOUND THE CLOCK: MEMORY CREATION AND MANIPULATION IN LABORATORY MICE

by by Carlo Coppetti

illustration by by Erin Schikowski

What would people do if it were possible to decide which moments to remember and which ones to bury? We may not be there yet, but current research suggests memory manipulation is slowly becoming reality.

<!--more-->
Researchers at the Medical College of Georgia have successfully erased certain memories from the brains of genetically modified mice, opening the floodgates for a whole new field of research possibilities and science fiction fantasies. In the experiments, specific memories first had to be instilled in lab mice by repeatedly exposing them to the same stimuli and situations. One mouse at a time was lured into a separate chamber where it would first hear an unpleasant tone and would then be exposed to a mild electrical shock. The sample mice would then make the natural associations: "chamber = a bad place" and "tone = pain is imminent." The mice would avoid the chamber while showing classic signs of fear such as increased breathing rates or attempting to escape whenever they heard the tone.
In the second part of the experiment, the scientists injected the mice with a newly developed chemical, containing substances that boosted production of the protein Alpha-CaM-Kinase II in the mouse's brain. When they exposed the mice to the usually fear-inducing tone, the mice remained calm and unaffected. The mice had apparently forgotten about their previous traumatic experiences. However, when these same mice were placed into the chamber of their cage only minutes later, they once again showed clear signs of anxiety and discomfort. Apparently, the momentary oversupply of CaMKII had an effect on some memories but not on others. Memories involving the tone were erased from the mice's brains while all others, including memories of the chamber remained completely untouched. This delicate extraction of one specific object or event from the memory of a test subject is what neurobiologists at the Medical College refer to as "selective erasure." In a process that is remarkably similar to what Jim Carrey's character goes through in the 2004 movie Eternal Sunshine of the Spotless Mind, the erasure of the mouse's memories is triggered by its recall. The act of remembering a certain event while sufficient amounts of CaMKII are present in the brain is precisely what triggers its erasure from the lab mouse's memories.
These observations do not only open up new possibilities for research but also lead us to change our conceptions of human memory itself. Most likely, the processes of accessing and creating memories are one and the same, meaning that the act of memory reading isn't actually reading at all; every time we access a memory we rewrite it, which means no memory can ever be objective. If our memory is altered every time we access it, over time, will it inevitably turn from fact to fantasy?
The protein that makes these far-reaching memory manipulations possible is called Alpha-CaM-Kinase II and is abundant in the brains of both mice and humans. In his research, Joe Tsien, co-director of the Medical College of Georgia, discovered that CaMKII is an important signaling protein for NMDA receptors--points on a cell where electrical signals from other cells are received. Tsien's work shows that when CaMKII is present in a mouse's brain, it inhibited the creation of new memories. Any memories accessed within that time frame were not rewritten; they were forgotten.
Dr. Tsien says we still have a long way to go: "The puzzle is an incredibly complex one, and getting to that point will take a vast amount of additional research. Human memory is so complicated, and we are just barely at the foot of the mountain." From merely treating phobia and trauma patients to "custom-tailoring" individual sets of memories, the potential of memory manipulation seems virtually unlimited. The eventual goal of this research, however, seems not to be just the erasure, but also the creation of memories: a step with unfathomable implications for the concept of individuality. If our memories define us, but are also interchangeable, then aren't we interchangeable? Indeed, continued progress in the field of memory manipulation could alter our conception of identity so profoundly that we must thank Dr. Tsien for giving us a little more time.

CARLO COPPETTI B'11 is still trying to remember his Friday night.