Selective amnesia — How a traumatic memory can be wiped outApril 02, 2007French CNRS scientists in collaboration have shown that a memory of a traumatic event can be wiped out, although other, associated recollections remain intact. This is what a scientist in the Laboratory for the Neurobiology of Learning, Memory and Communication (CNRS/Orsay University), working with an American team, has recently demonstrated in the rat. This result could be used to cure patients suffering from post-traumatic stress. Recalling an event stored in the long-term memory triggers a reprocessing phase: the recollection then becomes sensitive to pharmacological disturbances before being once more stored in the long-term memory. Is drug therapy capable of wiping out the initial memory, and only that memory? The scientists trained rats to be frightened of two distinct sounds, making them listen to these sounds just before sending an electric shock to their paws. The next day, they gave half of the rats a drug known to cause amnesia for events recalled from memory, and played just one of the sounds again. When they played both sounds to the rats on the next day, those which had not received the drug were still frightened of both sounds, while those which had received the drug were no longer afraid of the sound they had heard under its influence. Recalling the memory of the electric shock associated with the sound played while rats were under the influence of a drug thus meant that the memory was wiped out by the drug, leaving intact the memory associated with the other sound. The researchers also recorded the neuronal activity of rats in the amygdale, an area of the brain associated with emotional memory. Neuronal activity increased when remembering the traumatic memory, but diminished in drugged rats. This result showed that pharmacological disturbance of the memory recalled did indeed consist in selectively wiping out this memory, and only this memory. This is the first demonstration that a memory can be modified or even wiped out at the cellular level, permanently and independently of other memories associated with it. CNRS |
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| Related Amnesia Current Events and Amnesia News Articles Scientists decipher the formation of lasting memories Researchers at Karolinska Institutet have discovered a mechanism that controls the brain's ability to create lasting memories. In experiments on genetically manipulated mice, they were able to switch on and off the animals' ability to form lasting memories by adding a substance to their drinking water. Theory about long and short-term memory questioned by UCL scientists The long-held theory that our brains use different mechanisms for forming long-term and short-term memories has been challenged by new research from UCL, published today in PNAS. Brown Professor Continues Debate Over Recovered Memory Two years after two Harvard psychiatrists published a controversial paper on repressed memory, Brown University political scientist Ross Cheit is engaged in an academic dispute over that paper's integrity and its implications. Cheit's paper appears in the current issue of Journal of Trauma & Dissociation. Sick of the same old thing? U of Minnesota researcher finds satiation solution Have you ever gotten sick of pizza, playing the same computer game, or had a song stuck in your head for so long you never wanted to hear it again? An amnesic patient with an extraordinary distorted memory If somebody asks you "Do you remember what you did on March 13, 1985?" you are very likely to answer "I don't know", even if your memory is excellent. Humans may be losers if technological nature replaces the real thing There are Web cams focused on falcons, ferrets and fish, virtual tours of the Grand Canyon and Yosemite, and robotic dogs, seals and even dinosaurs. But what about the real deal: observing animals in their natural habitat, hiking the John Muir Trail or a playing with a live pet? Classifying concussions could help kids It's estimated that more than a half million kids in the U.S. go to the hospital each year with a concussion. Village bird study highlights loss of wildlife knowledge from one Our ability to conserve and protect wildlife is at risk because we are unable to accurately gauge how our environment is changing over time, says new research out today in Conservation Letters. That gut feeling may actually reflect a reliable memory You know the feeling. You make a decision you're certain is merely a "lucky guess." A new study from Northwestern University offers precise electrophysiological evidence that such decisions may sometimes not be guesswork after all. Plants display 'molecular amnesia' Plant researchers from McGill University and the University of California, Berkeley, have announced a major breakthrough in a developmental process called epigenetics. They have demonstrated for the first time the reversal of what is called epigenetic silencing in plants. More Amnesia Current Events and Amnesia News Articles |
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