cannabisnews.com: Chemical in Pot Puts Haze on Bad Memories





Chemical in Pot Puts Haze on Bad Memories
Posted by CN Staff on August 01, 2002 at 13:45:56 PT
By Adam Marcus, HealthScoutNews Reporter 
Source: HealthScout.com
Could smoking marijuana send bad memories up in smoke? A brain chemical similar to pot's active ingredient, THC, appears to be a sort of internal lotus blossom that helps mice forget fearful events from the past. Mice missing a receptor that recognizes this molecule, called a cannabinoid, can't shed nervous memories as effectively as their normal cage mates can, European researchers have found. 
The findings, reported in today's issue of Nature, don't speak directly to the effects of marijuana, which has a much broader impact on the brain. But they do suggest that people who use the drug may be "self-medicating" anxiety and fear by helping to extinguish negative recollections, the researchers say. Beat Lutz, of the Max Planck Institute of Psychiatry in Munich, Germany, and a co-author of the study, says the work also gives researchers a new lens through which to view emotional problems like phobias and post-traumatic stress disorder. Until now, Lutz says, scientists have concentrated on the roles of two brain messenger molecules, dopamine and serotonin, in these ailments. Now, he says, they should also consider the brain's internal, or endogenous, cannabinoid system. In their experiments, Lutz and his colleagues created a strain of mice missing a brain receptor for an endogenous cannabinoid. This receptor, CB1, resides in areas of the brain responsible for memory acquisition, processing and recall. It includes an almond-shaped center called the amygdala. Lutz's group ran these mice and a group of normal rodents through a common fear-conditioning test in which the animals heard a tone and got shocked. Later, the tone was repeated and all the animals froze, indicating that they'd acquired the negative memory and held onto it. When the researchers continued playing the tone, the normal mice eventually lost their fear of the sound as they extinguished the bad memory. But the receptor-less rodents kept freezing, unable to shed the anxiety of an impending shock. In addition, a drug that blocks CB1 receptors inhibited memory extinction in genetically normal mice, the researchers found. They also observed CB1 activity in a subset of neurons in the amygdala. The two groups of animals were essentially identical, having no differences in baseline anxiety, pain perception or ability to move, Lutz says. However, the mutant mice did seem to have a slightly suppressed sense of pleasure, he says, which translated into a weaker appetite. Although the study showed that the endogenous cannabinoid system is actively involved in fear memory extinction, Lutz doubts it's limited to negative associations. "Maybe it involves adaptation processes, where you have to modify or erase old memories and overwrite them with new ones," he says. So were Cheech and Chong really onto something? Not quite. Smoking marijuana might help extinguish bad memories, but it has also been shown to prevent the acquisition and processing of new ones, Lutz says. Pankaj Sah, a neuroscientist at the Australian National University in Canberra and author of a commentary on the study in Nature, says the latest findings hint at a role for cannabinoids in the treatment of anxiety disorders. "There is much anecdotal evidence of patients using cannabis heavily in the early stages of psychiatric illness," Sah wrote. "This has often been thought to contribute to acute illness. But it seems possible that it may instead be a form of self-medication for the sometimes extreme anxiety that these people experience." Richard Musty, a psychologist at the University of Vermont who studies marijuana, called the latest experiments "very neat work." But Musty says it's a stretch to conclude that cannabis might prove useful in treating anxiety and stress in humans. "They're working in the system that's basically the physiological reaction to fear," he says. "That doesn't take into account thoughts" that add much more complexity to memory. In other words, he adds, it's hard to compare a mouse that heard a bell and got shocked yesterday to a Vietnam veteran in a firefight 30 years ago. Source: HealthScout.comAuthor: Adam Marcus, HealthScoutNews Reporter Published: Thursday, August 1, 2002Copyright: 2002 Healthscout.com Contact: editors healthscoutnews.com Website: http://www.healthscout.com/Related Articles & Web Site:Naturehttp://www.nature.com/Study: Marijuana Eases Traumatic Memories http://cannabisnews.com/news/thread13601.shtmlPot Blocks Painful Memories, Study Says http://cannabisnews.com/news/thread13600.shtml'Natural' Cannabis Manages Memory http://cannabisnews.com/news/thread13598.shtmlPot-Like Chemical Helps Beat Fear http://cannabisnews.com/news/thread13596.shtml
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Comment #3 posted by Dan B on August 02, 2002 at 08:56:35 PT:
p4me
Thanks for the links, especially the YellowTimes article. That is certainly the best, most concise article I have yet read on the subject of the USA PATRIOT Act. The other articles are also quite good and definitely worth a read, but I think the USA PATRIOT Act is the most important of them all.Dan B
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Comment #2 posted by p4me on August 01, 2002 at 21:27:55 PT
Another small media victory
The New York Times actually has an article on Marijuana concerning the upcoming vote in Nevada. How many lawyers are consulting state and federal officials how to stop the ballot. I say at least 20 school buses. Here's the link: http://www.nytimes.com/2002/08/02/national/02POT.html
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Comment #1 posted by p4me on August 01, 2002 at 16:54:06 PT
A little political sidestep, thank you very much
This study has come in many forms in the last few days, so blabby old me would have already commented on the subject by now.But what the pill industry is doing to protect their proit flow is always relevant to marijuana. I just wanted to put up a link from Nation.com and a few paragraphs from it: http://www.thenation.com/doc.mhtml?i=special&s=newman20020725I also want to put up a link to the best article I have seen that would give indications of why I feel the way I do about the Patriot Act. This is a Yellowtimes article so you could print copies with their blessing as long as you credit them as instructed at the end of the article. If you do not know about the Patriot Act this is the one article I recommend along with a 6 part series by Jennifer Van Bergen called "Repeal the USA Patriot Act" at http://www.truthout.org/ that stays in the top center (5th link down) of the screen in hopes of discovery by an inquiring mind. Here is the Yellowtimes.org link: http://www.yellowtimes.org/article.php?sid=444FEATURE STORY | Special Report 
Big Pharma, Bad Science by Nathan Newman 
In June, the New England Journal of Medicine, one of the most respected medical journals, made a startling announcement. The editors declared that they were dropping their policy stipulating that authors of review articles of medical studies could not have financial ties to drug companies whose medicines were being analyzed.The reason? The journal could no longer find enough independent experts. Drug company gifts and "consulting fees" are so pervasive that in any given field, you cannot find an expert who has not been paid off in some way by the industry. 
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