Johns Hopkins Researchers Discover how to Erase Memory
2010 11 17
From: hopkinsmedicine.org
Researchers working with mice have discovered that by removing a protein from the region of the brain responsible for recalling fear, they can permanently delete traumatic memories. Their report on a molecular means of erasing fear memories in rodents appears this week in Science Express.
“When a traumatic event occurs, it creates a fearful memory that can last a lifetime and have a debilitating effect on a person’s life,” says Richard L. Huganir, Ph.D., professor and director of neuroscience at the Johns Hopkins University School of Medicine and a Howard Hughes Medical Institute investigator. “Our finding describing these molecular and cellular mechanisms involved in that process raises the possibility of manipulating those mechanisms with drugs to enhance behavioral therapy for such conditions as post-traumatic stress disorder.”
Behavioral therapy built around “extinction training” in animal models has proven helpful in easing the depth of the emotional response to traumatic memories, but not in completely removing the memory itself, making relapse common.
Huganir and postdoctoral fellow Roger Clem focused on the nerve circuits in the amygdala, the part of the brain known to underly so-called fear conditioning in people and animals. Using sound to cue fear in mice, they observed that certain cells in the amygdala conducted more current after the mouse was exposed to a loud, sudden tone.
In hopes of understanding the molecular underpinnings of fear memory formation, the team further examined the proteins in the nerve cells of the amygdala before and after exposure to the loud tone. They found temporary increases in the amount of particular proteins — the calcium-permeable AMPARs — within a few hours of fear conditioning that peaked at 24 hours and disappeared 48 hours later.
Because these particular proteins are uniquely unstable and can be removed from nerve cells, the scientists proposed that they might permanently remove fear by combining behavior therapy and protein removal and provide a window of opportunity for treatment. “The idea was to remove these proteins and weaken the connections in the brain created by the trauma, thereby erasing the memory itself,” says Huganir.
In further experiments, they found that removal of these proteins depends on the chemical modification of the GluA1 protein. Mice lacking this chemical modification of GluA1 recovered fear memories induced by loud tones, whereas littermates that still had normal GluA1 protein did not recover the same fear memories. Huganir suggests that drugs designed to control and enhance the removal of calcium-permeable AMPARs may be used to improve memory erasure.
“This may sound like science fiction, the ability to selectively erase memories,” says Huganir. “But this may one day be applicable for the treatment of debilitating fearful memories in people, such as post-traumatic stress syndrome associated with war, rape or other traumatic events.”
This study was funded by the National Institutes of Health and the Howard Hughes Medical Institute.
Authors on the paper are Roger L. Clem and Huganir, both of Johns Hopkins.
http://www.redicecreations.com/article.php?id=13217
除大腦蛋白刪痛苦記憶
2010年11月04日(四)
【本報訊】美國約翰斯霍普金斯大學科學家發現，通過移除大腦內特定蛋白，可永久刪除與之相關的痛苦記憶。研究人員先用突然的巨大聲響，令白老鼠產生恐懼，牠們大腦負責調節恐懼的區域，神經細胞會分泌名為AMPARs的蛋白，只要將之移除便能消除恐懼記憶。研究有助科學家研製出抑制和移除AMPARs蛋白的藥物，從而永久刪除災後創傷性記憶。
http://the-sun.on.cc/cnt/china_world/20101104/00423_033.html?pubdate=20101104
移走腦蛋白 實現《無痛失戀》
2010年11月04日(四)
【本報訊】科學家發現通過移除大腦內特定蛋白，可永久刪除與之相關的痛苦記憶。這一方法將來可以用來治療恐懼、創傷後情緒失控等病症，就像電影《無痛失戀》裏占基利和琦溫斯莉分手之後選擇抹去給彼此留下情感創傷記憶的情節一樣。
刪除痛苦記憶
這項研究在《科學快訊》發表，由美國約翰斯霍普金斯大學的哈加尼爾（Richard L Huganir）博士領導。研究人員先用突然的巨大聲響，令實驗老鼠產生恐懼，發現牠們大腦負責調節恐懼的區域，神經細胞會分泌一種名為AMPARs的蛋白，只要將之移除便能消除產生恐懼的記憶。
研究人員又發現，另有一種關鍵的蛋白GluA1，能抑制老鼠恢復恐懼記憶。哈加尼爾稱，這個研究有助科學家研製出抑制和移除AMPARs蛋白的藥物，從而永久刪除戰爭和強姦等災後創傷性記憶。
http://orientaldaily.on.cc/cnt/china_world/20101104/00180_044.html?pubdate=20101104
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