For thousands of years, people have thought that memory is stable and constant, like a biological harddrive. People tend to trust their recollections, because they feel authentic. However, all of this is wrong. The very act of remembering changes the memory itself.
Every time you recall a memory, the memory is warped by current knowledge and emotions. Basically, the memory must rebuild itself. Thus memory does not work like a movie, but like a play, constantly altering and changing each time it's performed.
A molecule called PKMzeta lurks around synapses in the brain. Without it, stable memories can easily disappear. Memories are like an engine, and without a constant supply of fuel, they will die. Thus the brain needs a constant supply of PKMzeta to preserve longterm memories. Scientists found that an inhibitor called ZIP blocks PKMzeta from the synapses. Without the steady supply of PKMzeta, the memory collapses, unable to sustain itself.
In an experiment, several dozen rats were taught to associate a loud noise with an electric shock. Whenever the noise played, the rats would freeze, anticipating the shock. After reinforcing this painful memory for several weeks, the rats were injected with ZIP. To the scientists' amazement, the rats stopped freezing. They had completely forgotten. This led to the conclusion that the molecular network of memories reforms every time they are accessed, because ZIP only erased the memory of the electric shock and nothing else.
As seen with the rats, specific memories can be erased. Humans could employ ZIP to create a hypothetical forgetting pill, treating PTSD and drug addiction. Experiments with morphine-addicted rats show that craving is a learned association; thus ZIP could delete memories and stop the addiction. In addition to erasing memories, research on the rats may also contribute to a cure for Alzheimer's.
In biology class, we learned that Alzheimer's is a condition wherein people lose their memory. While the article does not speculate upon this matter, scientists could hypothetically use PKMzeta to strengthen memories; instead of a "forgetting pill," there could also be a "remembering pill." Besides Alzheimers', we also studied the nervous system and its role in the human body. With PKMzeta and ZIP, we could potentially manipulate our own nervous system in the future. ZIP could increase homeostasis by preventing the domination of painful memories (PTSD) and stopping drug addiction.
Research of PKMzeta and ZIP seems to be a hotspot in the scientific community. Not only are these molecules intriguing, but they could led to cures for disorders involving memory. Maybe in the future, these molecules could improve daily life. Before the next day's biology test, you could take a remembering pill to enhance the PKMzeta in your brain, achieving abnormal retention.
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| How to use ZIP to erase memories. ORIGINAL ARTICLE: www Wired Com |
Source: Jonah Lehrer, February 17, 2012
http://www.wired.com/magazine/2012/02/ff_forgettingpill/all/1
How can a scientist control what specific memories the test subject forgets?
ReplyDeleteHow do they know that increasing the PKMzeta would prove effective in helping people improve their memory, and not prove harmful or not work at all? In other words, is this just a hypothesis?
ReplyDeleteNima --
ReplyDeleteWhen choosing what specific memory to forget, the secret is timing. First, choose a specific memory and have the subject write it down or tell it aloud several times to establish it. The next step is deleting it. As mentioned in the article, new proteins are created in the act of remembering; memories are like an engine constantly needing this protein fuel. If, however, something inhibits those proteins, the original memory will cease to exist. Thus to delete the memory, administer a drug that blocks the protein and ask the subject to recall the specific memory. Since the protein required to reinforce the memory is inhibited, the memory can no longer sustain itself. Thus, it shall cease to exist. Also, neuroscientists hypothesize that they can get even more specific by using drugs that target only specific areas of the brain for optimal accuracy. If the drug and memory are selective enough, the rest of the brain should remain the same.
Eliza --
While scientists have not yet tested PKMzeta on people to enhance memory, they have tested it on rats. Rats were given sweet, lithium-laced water that made them ill. A week after the illness (enough time for the memory to become long term), one group of rats was given injections to increase the activity of PKMzeta. In general, rats with high levels of PKMzeta remembered and did not drink the water when served it again a week after the injection; rats with normal levels of PKMzeta forgot and did drink the water. Since this is a fairly recent development in memory research, scientists have not yet studied PKMzeta intensively enough to discern any harmful effects. I hope they'll investigate on humans soon.
Source: http://www.scientificamerican.com/article.cfm?id=enzyme-strengthen-old-memories