SIGN OF CHANGE: Researchers have discovered how methamphetamine works its long-lasting, addictive effects on the brain.
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Scientists for the first time have identified long-term changes in mice brains that may shed light on why addicts get hooked on drugs—in this case methamphetamines—and have such a tough time kicking the habit. The findings, reported in the journal Neuron, could set the stage for new ways to block cravings—and help addicts dry out.
Researchers, using fluorescent tracer dye, discovered that mice given methamphetamines for 10 days (roughly equivalent to a human using it for two years) had suppressed activity in a certain area of their brains. Much to their surprise, normal function did not return even when the drug was stopped, but did when they administered a single dose of it again after the mice had been in withdrawal.
Study co-author Nigel Bamford, a pediatric neurologist at the University of Washington School of Medicine, says that if similar changes occur in humans, it will indicate that an effective way to fight addiction may be to design therapies that target the affected area—the striatum, a forebrain region that controls movement but also has been linked to habit-forming behavior.
Previous research has shown that the drug stimulates nerve cells in the midbrain to release dopamine into the synapses (connections between neurons) in the striatum. Dopamine (which is connected to reward processing, motivation and attention) is one of the brain's primary neurotransmitters, the chemical messengers by which one neuron triggers its neighbor to fire a nerve impulse.
In this case, Bamford says, the excess dopamine affected the flow of information from the cortex (the brain's central processing unit) to the striatum. Specifically, it appeared to partially block nerve cells in the cortex from releasing glutamate, another neurotransmitter, which is responsible for excitation. "Dopamine provides a filtering effect that may help you concentrate on the novel object or pleasurable stimulus," Bamford says. Too much could explain addictive or compulsive behavior, because it would help a user ignore other things and focus a lot of attention on one particular goal.
Researchers found that chronic use of the drug kept the brain in this state of "chronic depression," in essence suppressing the neural terminals controlling the flow of signals between the cortex and striatium—even after a long period of several weeks. But normal activity resumed after the drug was reintroduced.
Bamford believes the key lies in other neurons found in the striatum, which release the neurotransmitter acetylcholine that, he says, acts like a "memory switch". When dopamine is released by meth use, it lessens acetylcholine levels in the striatum; continued drug use reduces it to as low as 10 percent. This decrease, in turn, affects glutamate levels, which also drop perilously low, thereby resulting in the chronic depression of information flow in the brain.
When methamphetamine is administered after a period of withdrawal, however, the dopamine released by the midbrain neurons has the opposite effect on the acetylcholine cells, prompting them to release the chemical into the striatum. This, in turn, stimulates the production of glutamate, somehow causing the system to reset itself to a pre-addictive state.
Bamford says that if researchers can pinpoint the resetting mechanism, it would enable them to design nonaddictive drugs to trigger it.
"The identification of this quite complicated mechanism gives you different opportunities to address the root of the problem so the synapse can be renormalized without the use of the psychostimulant," he says. "A better target would be to determine how these [acetylcholine neurons] are learning to stay depressed and work directly with those."
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14 Comments
Add Commentthis article is stupid...of course the mice resumed normal function after receiving more meth...thats what meth heads do..they go buy more meth when they are in withdrawal to resume "normal" function. the way to get people to stop getting hooked on drugs is to stop the war against psychedelics and pot and redirect it towards the drugs THAT ACTUALLY KILL YOU....chew on that for a second...
Reply | Report Abuse | Link to thiscan the brain surely be rebooted to stop drug addiction?i dont understand.ruttodarius@yahoo.com.kenya
Reply | Report Abuse | Link to thisJust read this in M. Crichton's book titled " Next."
Reply | Report Abuse | Link to thisI pray to God that some day SOON there will be something I can take to curb my craving of crystal. It's not fun being an addict. In fact, it sucks! No longer is it a party, it's a way of life. I have to have it to function and I hate it. Being controlled by a little baggie of white powder/rocks in nothing that anyone can be proud of.
Reply | Report Abuse | Link to thisSo, I guess just one more last time would be the answer. Anyone want to go out and get high with me - so we can reboot and beat this thing once and for all? Last time! No more of this Twelve Stepin', helping others, God is Boss nonsense - just a big ol' REBOOT of the OS!
Reply | Report Abuse | Link to thisCLICK ON RESTART baby!
Science is proving to be more and more crazy with each attempt to regain control over the "addicitons" business - lost to AA and 12 Step Recovery long ago. The desperation of greed smells foul.
Danny S
http://recoveredalcoholic.blogspot.com/
Other than myself, is there anyone that read this article and isn't a junkie or dealer?
Reply | Report Abuse | Link to thisTHIS is quite interesting and possibly fundamental research toward finding some way to redirect the neural pathways involved in the scourge of meth addiction.
Reply | Report Abuse | Link to thisThat specific neuroanatomic regions and transmitter changes are identified is key toward any pharmacological strategies... especially the finding that simply stopping the meth did NOT normalize to pre-addiction function.
Regarding addicts in general... and sadly, for the one(s) posting here... they are clear examples of how we ourselves are the PRODUCTS of our neurobiology... which of course is genetically based and plays out in whatever environment we find ourselves.
The point is that free-will is but an illusion and that addiction, with the proven genetic, biochemical and neuropathologic changes exposes the folly of well-intentioned but judgemental and dimwitted "just say no" admonitions... or "pray to god" for strength from the faith-based.
Most of the [url http://www.drugrehabscenters.com/]drug/alcohol addiction treatment[/url] organizations are operated just to make profit out of drug treatment. So they are not client-specific. But there are many organizations which run for noble purpose of treatment of low income drug addicts.
Reply | Report Abuse | Link to thisSure does explain relapse and supports the concept of harm reduction in treatment.
Reply | Report Abuse | Link to thisScientists for the first time have identified long-term changes in mice brains that may shed light on why addicts get hooked on drugsin this case methamphetaminesand have such a tough time kicking the habit. The findings, reported in the journal Neuron, could set the stage for new ways to block cravingsand help addicts dry out. Researchers, using fluorescent tracer dye, discovered that mice given methamphetamines for 10 days (roughly equivalent to a human using it for two years) had suppressed activity in a certain area of their brains. Much to their surprise, normal function did not return even when the drug was stopped, but did when they administered a single dose of it again after the mice had been in withdrawal. Study co-author Nigel Bamford, a pediatric neurologist at the University of Washington School of Medicine, says that if similar changes occur in humans, it will indicate that an effective way to fight addiction may be to design therapies that target the affected areathe striatum, a forebrain region that controls movement but also has been linked to habit-forming behavior.
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Sarah
Washington Drug Addiction
Several of the drug and alcohol addiction treatment centers are operated just to make profit out of drug treatment. So they are not client-specific. But there are many organizations which run for noble purpose of treatment of low income drug addicts.
Reply | Report Abuse | Link to thishttp://www.addiction-treatments.com/
Methamphetamine is used as a stimulant to increase the physical activity and also illegally used for euphoria and elation. There are many <A HREF='http://www.addiction-treatments.com/'>effects of methamphetamine addiction </A>such as lack of concentration, chest pain and blurred vision.
Reply | Report Abuse | Link to thishttp://www.addiction-treatments.com/
Methamphetamine is used as a stimulant to increase the physical activity and also illegally used for euphoria and elation. There are many <A HREF='http://www.addiction-treatments.com/'>effects of methamphetamine addiction </A>such as lack of concentration, chest pain and blurred vision.
Reply | Report Abuse | Link to thishttp://www.addiction-treatments.com/
Spin-oza,
Reply | Report Abuse | Link to thisYour argument about how humans are the products of our neurobiology and how we have no free will is an illusion confuses me. How can you say that we are puppets of what our brain tells us to do? It is impossible for us to be controlled by our brains, because our brains are part of us. Your brain IS your identity so you can’t plead that you don’t have control over yourself. In the end, you always have free will, no matter the situation. Yes, your environment can slate your decisions, but you can ALWAYS say no. Also, I would say that you shouldn’t discount ‘prayer.’ While it is impossible to scientifically prove if God really answers our prayers, at the very least, people find additional motivation through their religion and their belief that God listens and answers our prayers, and that seems like a reward in itself.