Memory interuption interupts addiction in rats

More exciting, yet creepy, progress in experiments that interrupt addiction by interfering with memory reconsolidation:

Barry Everitt, an experimental psychologist at the University of Cambridge in England, focused his group's efforts on proteins called NMDA-type glutamate receptors in rat brains. Previous work on addiction and post-traumatic stress has shown that these proteins—which are found on the surface of brain cells—are essential to memory formation. The receptors are also crucial to reconsolidating a memory—moving it from its storage area in long-term memory to brain regions that handle short-term memory.

The researchers—who report their findings in the Journal of Neuroscience—put rats in a cage with a lever in it for a couple of hours per day for a week. When the animals pushed the lever, a light would come on and a cocaine solution would be dispensed to the rat. The rats began to associate the light they saw with cocaine.

After a couple weeks of forced sobriety, the animals were returned to the cage. Before going back in, some of the rats received injections of experimental drugs that block NMDA-type glutamate receptors in the amygdala—a brain region that has been implicated in drug-associated memories.

Both treated and untreated animals, when back in the cage, would press the lever over and over again. The light would come on, but no cocaine would be served. Untreated animals continued unfazed, hoping cocaine would eventually come out.

For the treated animals, however, Everitt says, "They press the lever, but it doesn't do anything, so they stop." The animals seemed to forget that the light in the cage meant cocaine was on its way for up to four weeks after only a single treatment.

Scientists say that suggests that by disrupting the recollection of a drug-associated memory—a person one abuses drugs with, a place that one uses drugs at, for example—a therapeutic may be able to break the connection between cues in the environment and the need for drugs. Sometimes these cues can be quite close to home—a family member or loved one.

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