“Memory cannot be defined, but it defines mankind.” ~Ghost in the Shell
“Until the process is fully completed, memory remains vulnerable to disruption.” ~Larry Squire and Eric Kandel, Memory: From Mind to Molecules
Where would we be without our memories? Our memories shape us, comfort us, teach us, trouble us. From them, we grow and love, we visit old friends and travel the lands of our past. They are our time machines, our instruction guides.
Scientists have been studying memory and the brain throughout human history, attempting to discover the inner workings of our marvelous minds. But sometimes, in order to see how something works, we have to first observe how it doesn’t.
In 2007, Professor Joseph LeDoux of New York University decided to do some research with rats (those furry mainstays of the science world) on the subject of memory erasure.
It was very Eternal Sunshine of him.
In LeDoux’s experiment, rats were trained to associate two musical tones with a mild electrical shock. As a result, whenever they heard either of these tones, they would brace themselves for the shock.
Our researchers then used a drug called U0126, which was already known to cause limited amnesia, on the rats when playing only one of the musical tones.
After treatment with the drug, the rats would not brace themselves upon hearing the treatment tone, but would still brace themselves when hearing the second, demonstrating only one memory had been deleted.
Though, of course, scientists are looking more at using this research for treating post-traumatic stress disorder and less for erasing memories of your crazy ex-girlfriend.
In a recent study led by Theodore Berger of the USC Viterbi School of Engineering and Sam A. Deadwyler of the Wake Forest Department of Physiology and Pharmacology, scientists have found a way to turn memories on and off. Like flipping a switch.
The research team had rats learn to press Lever A instead of Lever B in order to receive a reward. Deadwyler’s group recorded changes in brain activity between the two major internal divisions of the hippocampus (subregions CA3 and CA1), where short-term memory is converted to long-term memory.
They then drugged the rats, blocking the neural interactions between CA3 and CA1. This prevented the rats from being able to form long-term memories.
And this is where Berger’s team comes in. They developed an artificial hippocampal system that duplicates the patterns of CA3-CA1 interactions.
When they activated the electronic device, long-term memory capability was returned to the drugged rats.
“Flip the switch on, and the rats remember. Flip it off, and the rats forget,” Berger said.
…Science be crazy.