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Rehovot Scientists Finds a Drug to Erase Memories in Rats
"In the comedic science-fiction film “Men in Black,” a top-secret team uses a “memory eraser” to make people forget they’ve seen aliens. Memory erasure is a recurrent theme in science fiction, but until recently it has stayed in that realm only.
That’s changing. For the first time, researchers say they have erased specific memories in rats weeks after the memories were formed.
The finding comes on the heels of another study a year ago in which scientists erased one-day old memories of spatial information from rats. But it was unknown then whether that could work for more established or complex memories, the scientists said; now it’s becoming apparent that it can.
The findings can serve to benefit people, such as for treatments to enhance memory or erase traumatic recollections, the researchers added. But some authors have also predicted potential for abuse of such treatments. For instance, one might blot out a memory to keep someone from testifying about a crime. “Only the inherent goodness of our fellow men and women” can prevent abuse, wrote one of the scientists, Todd Sacktor of SUNY Downstate Medical Center in Brooklyn, N.Y., in an email.
Sacktor is part of a team—along with Yadin Dudai of the Weizmann Institute of Science in Rehovot, Israel—of researchers studying what happens in our brains when we learn and remember. Memories aren’t recorded as a stable physical change, like writing an inscription on a clay tablet, they have found. Rather, long-term memory storage is a dynamic process, involving a miniature molecular machine that must run constantly to keep memories alive. Jamming the machine briefly can erase long-term memories, they say.
In their new study, to appear in the Aug. 17 issue of the research journal Science, they trained rats to avoid certain tastes. They then injected into the taste cortex—a brain area linked to taste memory—a drug that would block the actions of a particular molecule. They hypothesized, based on earlier research, that this molecule is a miniature memory “machine” that keeps memory up and running.
The molecule is an enzyme called PKMzeta. An enzyme is a protein molecule that causes changes in other proteins. PKMzeta lies in synapses, contact points between nerve cells where they pass messages to each other in the brain. The enzyme causes the structure of these contacts points to change subtly.
But the molecule must be persistently active to maintain this change, researchers found. Learning brings about this activity. Silencing PKMzeta reverses the change: regardless of the taste the rats were trained to avoid, they forgot their learned aversion after one injection of the drug.
The technique worked as successfully a month after the memories were formed, equivalent to years for a human, the researchers said. All signs so far indicate that the unpleasant memories were gone, they added. “This drug is a molecular version of jamming the operation of the machine,” said Dudai. “When the machine stops, the memories stop.”
In a previous study in the Aug. 25, 2006 Science, a group including Sacktor found that a similar treatment could erase one-day-old memories of spatial information in rats. But this work, researchers said, shed little light on PKMzeta activity in the neocortex, the brain region considered responsible for permanently storing most long-term memories. These include memories required for higher-level cognitive functions, such as language and complex thought. The new work focused on that area of the brain.
Yivsam Azgad, a spokesman for the Weizmann Institute, wrote in an email that he thinks abuse of the findings can be prevented only through “ethics, and by the laws of each country.” As with all research, he added, it’s scientists’ job to gain new knowledge, and society’s to use it responsibly."
My Rehovot previously disclosed ("Criminality or Irregularity? Israel State Comptroller Finds Weizmann Institute Fools Funding Bodies", 4 February 2007) that Yadin Dudai was included (without his knowledge) in grants by other less successful Weizmann Scientists. No doubts this academic misconduct (aiming to improve poor ranking of corresponding grant applications) could be assisted and directed by the corrupted Institutional academic office, headed by Mr. Boaz Avron.
Source: Drug found to erase memories in rats. World Science (16 August 2007) [FullText]
That’s changing. For the first time, researchers say they have erased specific memories in rats weeks after the memories were formed.
The finding comes on the heels of another study a year ago in which scientists erased one-day old memories of spatial information from rats. But it was unknown then whether that could work for more established or complex memories, the scientists said; now it’s becoming apparent that it can.
The findings can serve to benefit people, such as for treatments to enhance memory or erase traumatic recollections, the researchers added. But some authors have also predicted potential for abuse of such treatments. For instance, one might blot out a memory to keep someone from testifying about a crime. “Only the inherent goodness of our fellow men and women” can prevent abuse, wrote one of the scientists, Todd Sacktor of SUNY Downstate Medical Center in Brooklyn, N.Y., in an email.
Sacktor is part of a team—along with Yadin Dudai of the Weizmann Institute of Science in Rehovot, Israel—of researchers studying what happens in our brains when we learn and remember. Memories aren’t recorded as a stable physical change, like writing an inscription on a clay tablet, they have found. Rather, long-term memory storage is a dynamic process, involving a miniature molecular machine that must run constantly to keep memories alive. Jamming the machine briefly can erase long-term memories, they say.
In their new study, to appear in the Aug. 17 issue of the research journal Science, they trained rats to avoid certain tastes. They then injected into the taste cortex—a brain area linked to taste memory—a drug that would block the actions of a particular molecule. They hypothesized, based on earlier research, that this molecule is a miniature memory “machine” that keeps memory up and running.
The molecule is an enzyme called PKMzeta. An enzyme is a protein molecule that causes changes in other proteins. PKMzeta lies in synapses, contact points between nerve cells where they pass messages to each other in the brain. The enzyme causes the structure of these contacts points to change subtly.
But the molecule must be persistently active to maintain this change, researchers found. Learning brings about this activity. Silencing PKMzeta reverses the change: regardless of the taste the rats were trained to avoid, they forgot their learned aversion after one injection of the drug.
The technique worked as successfully a month after the memories were formed, equivalent to years for a human, the researchers said. All signs so far indicate that the unpleasant memories were gone, they added. “This drug is a molecular version of jamming the operation of the machine,” said Dudai. “When the machine stops, the memories stop.”
In a previous study in the Aug. 25, 2006 Science, a group including Sacktor found that a similar treatment could erase one-day-old memories of spatial information in rats. But this work, researchers said, shed little light on PKMzeta activity in the neocortex, the brain region considered responsible for permanently storing most long-term memories. These include memories required for higher-level cognitive functions, such as language and complex thought. The new work focused on that area of the brain.
Yivsam Azgad, a spokesman for the Weizmann Institute, wrote in an email that he thinks abuse of the findings can be prevented only through “ethics, and by the laws of each country.” As with all research, he added, it’s scientists’ job to gain new knowledge, and society’s to use it responsibly."
My Rehovot previously disclosed ("Criminality or Irregularity? Israel State Comptroller Finds Weizmann Institute Fools Funding Bodies", 4 February 2007) that Yadin Dudai was included (without his knowledge) in grants by other less successful Weizmann Scientists. No doubts this academic misconduct (aiming to improve poor ranking of corresponding grant applications) could be assisted and directed by the corrupted Institutional academic office, headed by Mr. Boaz Avron.
Source: Drug found to erase memories in rats. World Science (16 August 2007) [FullText]
Labels: Weizmann Institute
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