Chapter 4. The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
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Daniel Cressey The controversy over electronic cigarettes has been reignited today with the publication of a study claiming that they do not help smokers to quit their habit. Whether or not ‘e-cigarettes’ are an effective aid in the cessation of smoking has become a major issue for the rapidly growing industry that produces the devices, and for the tobacco researchers struggling to assess their impact. There is widespread agreement that inhaling from an e-cigarette, where a heating element vapourizes a liquid containing nicotine, is not as harmful as smoking a conventional cigarette, and proponents say that the products could save millions of lives. But some researchers and tobacco-control activists fear that the devices could make tobacco use seem socially acceptable again and may not assist people in actually reducing their addiction. Pamela Ling, a tobacco researcher at the University of California, San Francisco, and her colleagues followed 949 people who detailed their smoking habits though an online survey, and found that 88 of those who had used e-cigarettes were no more likely to have quit or reduced their smoking after a year than other smokers. “We found that there was no difference in the rate of quitting between smokers who used an e-cigarette and those who did not”, even after controlling for factors such as the user's dependence on tobacco, Ling told Nature in an e-mail. She added: “Advertising suggesting that e-cigarettes are effective for smoking cessation should be prohibited until such claims are supported by scientific evidence.” Her team reports the results today in JAMA Internal Medicine1. © 2014 Nature Publishing Group
Keyword: Drug Abuse
Link ID: 19405 - Posted: 03.25.2014
By MATT RICHTEL A dangerous new form of a powerful stimulant is hitting markets nationwide, for sale by the vial, the gallon and even the barrel. The drug is nicotine, in its potent, liquid form — extracted from tobacco and tinctured with a cocktail of flavorings, colorings and assorted chemicals to feed the fast-growing electronic cigarette industry. These “e-liquids,” the key ingredients in e-cigarettes, are powerful neurotoxins. Tiny amounts, whether ingested or absorbed through the skin, can cause vomiting and seizures and even be lethal. A teaspoon of even highly diluted e-liquid can kill a small child. But, like e-cigarettes, e-liquids are not regulated by federal authorities. They are mixed on factory floors and in the back rooms of shops, and sold legally in stores and online in small bottles that are kept casually around the house for regular refilling of e-cigarettes. Evidence of the potential dangers is already emerging. Toxicologists warn that e-liquids pose a significant risk to public health, particularly to children, who may be drawn to their bright colors and fragrant flavorings like cherry, chocolate and bubble gum. “It’s not a matter of if a child will be seriously poisoned or killed,” said Lee Cantrell, director of the San Diego division of the California Poison Control System and a professor of pharmacy at the University of California, San Francisco. “It’s a matter of when.” © 2014 The New York Times Company
By Ariana Eunjung Cha, Millions of ordinary Americans are now able to walk into a marijuana dispensary and purchase bags of pot on the spot for a variety of medical ailments. But if you’re a researcher like Sue Sisley, a psychiatrist who studies post- traumatic stress disorder, getting access to the drug isn’t nearly so easy. That’s because the federal government has a virtual monopoly on growing and cultivating marijuana for scientific research, and getting access to the drug requires three separate levels of approval. Marijuana offers hope for 6-year-old girl with rare condition: In marijuana, Lydia Schaeffer’s family members think they might have found a treatment that works. Now, they are trying to help legalize the drug. Sisley’s fight to get samples for her study — now in its fourth month — illuminates the complex politics of marijuana in the United States. While 20 states and the District have made medical marijuana legal — in Colorado and Washington state the drug is also legal for recreational use — it remains among the most tightly controlled substances under federal law. For scientists, that means extra steps to obtain, transport and secure the drug — delays they say can slow down their research by months or even years. © 1996-2014 The Washington Post
Sara Reardon Thomas Insel, the director of the US National Institute of Mental Health (NIMH), has had enough of shooting in the dark. He thinks that if a clinical trial of a psychiatric therapy fails, scientists should at least learn something about the brain along the way. Now Insel is translating that belief into action: the NIMH, based in Bethesda, Maryland, has decided to stop funding clinical trials that aim merely to ease patients’ symptoms. “Future trials will follow an experimental medicine approach in which interventions serve not only as potential treatments, but as probes to generate information about the mechanisms underlying a disorder”, he wrote in a 27 February blog post announcing the move. This funding switch, which will affect grants due to be made in a few months’ time, intensifies the NIMH’s apparent shift in emphasis from abstract psychiatry to the neurobiological roots of disease. “It’s a totally new departure for us,” says Bruce Cuthbert, a clinical psychologist and director of the institute’s adult translational-research division. Insel notes that the NIMH spent about US$100 million on clinical trials in 2013, and says that more than half of recipient projects received funding without any requirement to examine the biological processes involved in a disease. In many cases, “if you get a negative result you have no idea why, and you have to try something else at random”, Cuthbert says. “It’s an incredible waste of money.” The new rules, which will apply to the grant cycle that begins in June, also seek to increase transparency by requiring faster online registration of trials and stricter guidelines for reporting results. Insel acknowledges that researchers may have to rework their studies to satisfy the new guidelines. “I think this will be really unpopular,” he says. © 2014 Nature Publishing Group
by Clare Wilson ARE people with obsessive compulsive disorder addicted to their repetitive behaviours? In a test designed to measure decision-making, individuals with OCD performed much like gambling addicts, suggesting their underlying brain problems may be similar. OCD makes people worry obsessively, compelling them to carry out rituals like repeated hand washing. It affects about one in 50 people and can take over their lives. Because sufferers get anxious if they can't complete their rituals, OCD is usually treated as an anxiety disorder with talking therapies to relieve distress or anti-anxiety drugs. These approaches reduce symptoms but only a minority of people are cured. In the new study, 80 people – half of whom had OCD – had to choose cards from four decks, winning or losing money in the process. Two decks were rigged to produce big wins but even bigger losses. The people without OCD learned to choose from the two safer decks but those with the disorder were consistently less likely to make good judgements and finished with a significantly lower final score. Drug and gambling addicts also perform poorly on the test. That doesn't prove OCD is an addiction but a growing body of work, including brain scans and other cognitive tests, suggest it should be recast in this way, says Naomi Fineberg of the University of Hertfordshire in Welwyn Garden City. Both addiction and OCD "share a lack of control of behaviour", she says. © Copyright Reed Business Information Ltd.
Imagine that, after feeling unwell for a while, you visit your GP. "Ah," says the doctor decisively, "what you need is medication X. It's often pretty effective, though there can be side-effects. You may gain weight. Or feel drowsy. And you may develop tremors reminiscent of Parkinson's disease." Warily, you glance at the prescription on the doctor's desk, but she hasn't finished. "Some patients find that sex becomes a problem. Diabetes and heart problems are a risk. And in the long term the drug may actually shrink your brain … " This scenario may sound far-fetched, but it is precisely what faces people diagnosed with schizophrenia. Since the 1950s, the illness has generally been treated using antipsychotic drugs – which, as with so many medications, were discovered by chance. A French surgeon investigating treatments for surgical shock found that one of the drugs he tried – the antihistamine chlorpromazine – produced powerful psychological effects. This prompted the psychiatrist Pierre Deniker to give the drug to some of his most troubled patients. Their symptoms improved dramatically, and a major breakthrough in the treatment of psychosis seemed to have arrived. Many other antipsychotic drugs have followed in chlorpromazine's wake and today these medications comprise 10% of total NHS psychiatric prescriptions. They are costly items: the NHS spends more on these medications than it does for any other psychiatric drug, including antidepressants. Globally, around $14.5bn is estimated to be spent on antipsychotics each year. Since the 1950s the strategy of all too many NHS mental health teams has been a simple one. Assuming that psychosis is primarily a biological brain problem, clinicians prescribe an antipsychotic medication and everyone does their level best to get the patient to take it, often for long periods. There can be little doubt that these drugs make a positive difference, reducing delusions and hallucinations and making relapse less likely – provided, that is, the patient takes their medication. © 2014 Guardian News and Media Limited
Link ID: 19336 - Posted: 03.08.2014
by Bruce Bower Actor Philip Seymour Hoffman’s February death from a drug overdose triggered media reports blaming the terrible disease of addiction for claiming another life. But calling addiction a “disease” may be misguided, according to an alternative view with some scientific basis. Most people who are addicted to cigarette smoking, alcohol or other drugs manage to quit, usually on their own, after experiencing major attitude adjustments. Although relapses occur, successes ultimately outnumber fatalities. People can permanently walk away from addiction. Evidence that addiction is a solvable coping problem rather than a chronic, recurring disease seems like encouraging news. But it’s highly controversial. Neuroscientists and many clinicians regard drug addictions as brain illnesses best vanquished with the help of medications that fight cravings and withdrawal. From this perspective, drug-induced brain changes increase a person’s thirst for artificial highs and make quitting progressively more difficult. This conflict over addiction’s nature plays out in two lines of research: studies of remission and relapse among treated substance abusers and long-term studies of the general population. Follow-up investigations of people who attend treatment programs report that addicts never completely shake an urge to snort, inject, guzzle or otherwise consume their poisons of choice. Ongoing treatment in psychotherapy, rehab centers or 12-step groups encourages temporary runs of sobriety, but it’s easier to kick the bucket than to kick the habit. Surveys and long-term studies of the general population, however, observe that addicts typically spend their youth in a substance-induced haze but drastically cut back or quit using drugs altogether by early adulthood. Most of those who renounce the “high” life do so without formal treatment. © Society for Science & the Public 2000 - 2013.
Keyword: Drug Abuse
Link ID: 19332 - Posted: 03.08.2014
By SABRINA TAVERNISE Middle and high school students who used electronic cigarettes were more likely to smoke real cigarettes and less likely to quit than students who did not use the devices, a new study has found. They were also more likely to smoke heavily. But experts are divided about what the findings mean. The study’s lead author, Stanton Glantz, a professor of medicine at the University of California, San Francisco, who has been critical of the devices, said the results suggested that the use of e-cigarettes was leading to less quitting, not more. “The use of e-cigarettes does not discourage, and may encourage, conventional cigarette use among U.S. adolescents,” the study concluded. It was published online in the journal JAMA Pediatrics on Thursday. But other experts said the data did not support that interpretation. They said that just because e-cigarettes are being used by youths who smoke more and have a harder time quitting does not mean that the devices themselves are the cause of those problems. It is just as possible, they said, that young people who use the devices were heavier smokers to begin with, or would have become heavy smokers anyway. “The data in this study do not allow many of the broad conclusions that it draws,” said Thomas J. Glynn, a researcher at the American Cancer Society. The study is likely to stir the debate further over what electronic cigarettes mean for the nation’s 45 million smokers, about three million of whom are middle and high school students. Some experts worry that e-cigarettes are a gateway to smoking real cigarettes for young people, though most say the data is too skimpy to settle the issue. Others hope the devices could be a path to quitting. So far, the overwhelming majority of young people who use e-cigarettes also smoke real cigarettes, a large federal survey published last year found. Still, while e-cigarette use among youths doubled from 2011 to 2012, regular cigarette smoking for youths has continued to decline. The rate hit a record low in 2013 of 9.6 percent, down by two-thirds from its peak in 1997. © 2014 The New York Times Company
Keyword: Drug Abuse
Link ID: 19331 - Posted: 03.08.2014
By BENEDICT CAREY He heard about the drug trial from a friend in Switzerland and decided it was worth volunteering, even if it meant long, painful train journeys from his native Austria and the real possibility of a mental meltdown. He didn’t have much time, after all, and traditional medicine had done nothing to relieve his degenerative spine condition. “I’d never taken the drug before, so I was feeling — well, I think the proper word for it, in English, is dread,” said Peter, 50, an Austrian social worker, in a telephone interview; he asked that his last name be omitted to protect his identity. “There was this fear that it could all go wrong, that it could turn into a bad trip.” On Tuesday, The Journal of Nervous and Mental Disease is posting online results from the first controlled trial of LSD in more than 40 years. The study, conducted in the office of a Swiss psychiatrist near Bern, tested the effects of the drug as a complement to talk therapy for 12 people nearing the end of life, including Peter. Most of the subjects had terminal cancer, and several died within a year after the trial — but not before having a mental adventure that appeared to have eased the existential gloom of their last days. “Their anxiety went down and stayed down,” said Dr. Peter Gasser, who conducted the therapy and followed up with his patients a year after the trial concluded. The new publication marks the latest in a series of baby steps by a loose coalition of researchers and fund-raisers who are working to bring hallucinogens back into the fold of mainstream psychiatry. Before research was banned in 1966 in the United States, doctors tested LSD’s effect for a variety of conditions, including end-of-life anxiety. But in the past few years, psychiatrists in the United States and abroad — working with state regulators as well as ethics boards — have tested Ecstasy-assisted therapy for post-traumatic stress; and other trials with hallucinogens are in the works. © 2014 The New York Times Company
The teenager's brain has a lot of developing to do: It must transform from the brain of a child into the brain of an adult. Some researchers worry how marijuana might affect that crucial process. "Actually, in childhood our brain is larger," says , director of the brain imaging and neuropsychology lab at University of Wisconsin, Milwaukee. "Then, during the teenage years, our brain is getting rid of those connections that weren't really used, and it prunes back. "It actually makes the brain faster and more efficient." The streamlining process ultimately helps the brain make judgments, think critically and remember what it has learned. Lisdahl says it's a mistake for teenagers to use cannabis. "It's the absolute worst time," she says, because the mind-altering drug can disrupt development. Think of the teen years, she says, as the "last golden opportunity to make the brain as healthy and smart as possible." Lisdahl points to a growing number of that show regular marijuana use — once a week or more — actually changes the structure of the teenage brain, specifically in areas dealing with memory and problem solving. That can affect cognition and academic performance, she says. "And, indeed, we see, if we look at actual grades, that chronic marijuana-using teens do have, on average, one grade point lower than their matched peers that don't smoke pot," Lisdahl says. ©2014 NPR
By Ariana Eunjung Cha, Standing in a Wisconsin State Capitol hearing room surrounded by parents hugging their seriously ill children, Sally Schaeffer began to cry as she talked about her daughter. Born with a rare chromosomal disorder, 6-year-old Lydia suffers from life-threatening seizures that doctors haven’t been able to control despite countless medications. The family’s last hope: medical marijuana. Schaeffer, 39, didn’t just ask lawmakers to legalize the drug. She begged. “If it was your child and you didn’t have options, what would you do?” she said during her testimony in Madison on Feb. 12. The representatives were so moved that they introduced a bipartisan bill to allow parents in situations similar to Schaeffer’s to use the drug on their children. Emboldened by stories circulated through Facebook, Twitter and the news media about children with seizure disorders who have been successfully treated with a special oil extract made from cannabis plants, mothers have become the new face of the medical marijuana movement. Similar scenes have been playing out in recent weeks in other states where medical marijuana remains illegal: Oklahoma, Florida, Georgia, Utah, New York, North Carolina, Alabama, Kentucky. The “mommy lobby” has been successful at opening the doors to legalizing marijuana — if only a crack, in some places — where others have failed. In the 1970s and ’80s, mothers were on the other side of the issue, successfully fending off efforts to decriminalize marijuana with heartbreaking stories about how their teenage children’s lives unraveled when they began to use the drug. © 1996-2014 The Washington Post
By SABRINA TAVERNISE Dr. Michael Siegel, a hard-charging public health researcher at Boston University, argues that e-cigarettes could be the beginning of the end of smoking in America. He sees them as a disruptive innovation that could make cigarettes obsolete, like the computer did to the typewriter. But his former teacher and mentor, Stanton A. Glantz, a professor of medicine at the University of California, San Francisco, is convinced that e-cigarettes may erase the hard-won progress achieved over the last half-century in reducing smoking. He predicts that the modern gadgetry will be a glittering gateway to the deadly, old-fashioned habit for children, and that adult smokers will stay hooked longer now that they can get a nicotine fix at their desks. These experts represent the two camps now at war over the public health implications of e-cigarettes. The devices, intended to feed nicotine addiction without the toxic tar of conventional cigarettes, have divided a normally sedate public health community that had long been united in the fight against smoking and Big Tobacco. The essence of their disagreement comes down to a simple question: Will e-cigarettes cause more or fewer people to smoke? The answer matters. Cigarette smoking is still the single largest cause of preventable death in the United States, killing about 480,000 people a year. Dr. Siegel, whose graduate school manuscripts Dr. Glantz used to read, says e-cigarette pessimists are stuck on the idea that anything that looks like smoking is bad. “They are so blinded by this ideology that they are not able to see e-cigarettes objectively,” he said. Dr. Glantz disagrees. “E-cigarettes seem like a good idea,” he said, “but they aren’t.” © 2014 The New York Times Company
Keyword: Drug Abuse
Link ID: 19284 - Posted: 02.24.2014
By NICHOLAS RICCARDI, Associated Press COLORADO SPRINGS, Colo. (AP) — The doctors were out of ideas to help 5-year-old Charlotte Figi. Suffering from a rare genetic disorder, she had as many as 300 grand mal seizures a week, used a wheelchair, went into repeated cardiac arrest and could barely speak. As a last resort, her mother began calling medical marijuana shops. Two years later, Charlotte is largely seizure-free and able to walk, talk and feed herself after taking oil infused with a special pot strain. Her recovery has inspired both a name for the strain of marijuana she takes that is bred not to make users high — Charlotte's Web — and an influx of families with seizure-stricken children to Colorado from states that ban the drug. "She can walk, talk; she ate chili in the car," her mother, Paige Figi, said as her dark-haired daughter strolled through a cavernous greenhouse full of marijuana plants that will later be broken down into their anti-seizure components and mixed with olive oil so patients can consume them. "So I'll fight for whomever wants this." Doctors warn there is no proof that Charlotte's Web is effective, or even safe. In the frenzy to find the drug, there have been reports of non-authorized suppliers offering bogus strains of Charlotte's Web. In one case, a doctor said, parents were told they could replicate the strain by cooking marijuana in butter. Their child went into heavy seizures. "We don't have any peer-reviewed, published literature to support it," Dr. Larry Wolk, the state health department's chief medical officer, said of Charlotte's Web. Still, more than 100 families have relocated since Charlotte's story first began spreading last summer, according to Figi and her husband. The relocated families have formed a close-knit group in Colorado Springs, the law-and-order town where the dispensary selling the drug is located. They meet for lunch, support sessions and hikes. © 2014 Hearst Communications, Inc.
By MAGGIE KOERTH-BAKER If you are pulled over on suspicion of drunken driving, the police officer is likely to ask you to complete three tasks: Follow a pen with your eyes while the officer moves it back and forth; get out of the car and walk nine steps, heel to toe, turn on one foot and go back; and stand on one leg for 30 seconds. Score well on all three of these Olympic events, and there’s a very good chance that you are not drunk. This so-called standard field sobriety test has been shown to catch 88 percent of drivers under the influence of alcohol. But it is nowhere near as good at spotting a stoned driver. In a 2012 study published in the journal Psychopharmacology, only 30 percent of people under the influence of THC, the active ingredient in marijuana, failed the field test. And its ability to identify a stoned driver seems to depend heavily on whether the driver is accustomed to being stoned. A 21-year-old on his first bender and a hardened alcoholic will both wobble on one foot. But the same is not necessarily true of a driver who just smoked his first joint and the stoner who is high five days a week. In another study, 50 percent of the less frequent smokers failed the field test. As more states legalize medical and recreational marijuana, distinctions like these will grow more and more important. But science’s answers to crucial questions about driving while stoned — how dangerous it is, how to test for impairment, and how the risks compare to driving drunk — have been slow to reach the general public. “Our goal is to put out the science and have it used for evidence-based drug policy,” said Marilyn A. Huestis, a senior investigator at the National Institute on Drug Abuse. “But I think it’s a mishmash.” © 2014 The New York Times Company
Keyword: Drug Abuse
Link ID: 19260 - Posted: 02.18.2014
By Brian Palmer, The death of Philip Seymour Hoffman this month has raised many questions about drug addiction, among them: What do drugs such as heroin do to the brain to make them so addictive? Can these chemical changes be undone? Over the past 20 years, research into drug addiction has identified several chemical and physical changes to the brain brought on by addictive substances. There is a wad of nerve cells in the central part of your brain, measuring about half an inch across, called the nucleus accumbens. When you eat a doughnut, have sex or do something else that your brain associates with survival and breeding, this region is inundated with dopamine, a neurotransmitter. This chemical transaction is partly responsible for the experience of pleasure you get from these activities. Drugs such as heroin also trigger this response, but the dopamine surge from drugs is faster and long-lasting. When a person repeatedly subjects his nucleus accumbens to this narcotic-induced flood, the nerve cells that dopamine acts upon become exhausted from stimulation. The brain reacts by dampening its dopamine response — not just to heroin or cocaine, but probably to all forms of pleasurable behavior. In addition, some of the receptors themselves appear to die off. As a result, hyper-stimulating drugs become the only way to trigger a palpable dopamine response. Drug addicts seek larger and larger hits to achieve an ever-diminishing pleasure experience, and they have trouble feeling satisfaction from the things that healthy people enjoy. Behavioral conditioning also plays a role. Once your brain becomes accustomed to the idea that eating a doughnut or having sex will provide pleasure, just seeing a doughnut or an attractive potential mate triggers the dopamine cascade into the nucleus accumbens. That’s part of the reason it is so difficult for recovering drug addicts to stay clean over the long term. Sights, sounds and smells associated with the drug high — needles, for example, or the friends with whom they used to get high — prime this dopamine response, and the motivation to seek the big reward of a drug hit builds. © 1996-2014 The Washington Post
Keyword: Drug Abuse
Link ID: 19259 - Posted: 02.18.2014
By Ben Cimons, Recently I received an e-mail from my mother with a link to the harrowing tale of a 16-year-old Northern Virginia girl who overdosed on heroin and died, and whose companions had dumped her body. My mom wrote that she found the story “terrifying, because that easily could have been you. I thank God every day that it wasn’t, and that you are safe and healthy.’’ She was right. It could have been me, and it very nearly was. The only difference was that after I passed out from an accidental heroin overdose, the person I was with called 911 before abandoning me. Today I am 23 years old, living in a recovery house in Wilmington, N.C., and slowly regaining my life. But it has not been easy. Heroin is seductive. The minute it hits you, all your worries disappear. You are content with everything. You feel warm. You can’t help but smile. You feel free. The first time I tried it, I found an escape from the feelings of sadness and isolation I had been experiencing for as long as I could remember. But once heroin gets a hold on you, it never lets go. Heroin has been in the news a lot lately, most recently because of the death, apparently by overdose, of actor Philip Seymour Hoffman. Heroin is everywhere. It’s easy to find, including in the suburbs where I lived until recently, and cheaper than prescription pills. © 1996-2014 The Washington Post
Keyword: Drug Abuse
Link ID: 19244 - Posted: 02.13.2014
By DEBORAH SONTAG HUDSON, Wis. — Karen Hale averts her eyes when she drives past the Super 8 motel in this picturesque riverfront town where her 21-year-old daughter, Alysa Ivy, died of an overdose last May. She has contemplated asking the medical examiner, now a friend, to accompany her there so she could lie on the bed in Room 223 where her child’s body was found. But Ms. Hale, 52, is not ready, just as she is not ready to dismantle Ms. Ivy’s bedroom, where an uncapped red lipstick sits on the dresser and a teddy bear on the duvet. The jumble of belongings both comforts and unsettles her — colorful bras, bangle bracelets and childhood artwork; court summonses; a 12-step bible; and a Hawaiian lei, bloodstained, that her daughter used as a tourniquet for shooting heroin into her veins. “My son asked me not to make a shrine for her,” Ms. Hale said. “But I don’t know what to do with her room. I guess on some level I’m still waiting for her to come home. I’d be so much more empathetic now. I used to take it personal, like she was doing this to me and I was a victim.” When the actor Philip Seymour Hoffman died with a needle in his arm on Feb. 2, Ms. Hale thought first about his mother, then his children. Few understand the way addiction mangles families, she said, and the rippling toll of the tens of thousands of fatal heroin and painkiller overdoses every year. Perhaps it took Mr. Hoffman’s death, she said, to “wake up America to all the no-names who passed away before him,” leaving a cross-country trail of bereavement. © 2014 The New York Times Company
Keyword: Drug Abuse
Link ID: 19235 - Posted: 02.11.2014
You probably saw dozens of people’s faces today, many more if you live in a city. You may not have been conscious of it, but you were subtly judging every one by its beauty. Your eyes are drawn to more attractive faces, and the almost inescapable result is that more attractive people have advantages in almost every aspect of life, from job interviews to prison sentencing. But what drives us to crave beauty? According to one theory, gazing upon beauty stimulates the brain’s μ-opioid receptors (MOR), thought to be a key part of our biochemical reward system. At least in rodents, stimulating or inhibiting MOR neurotransmission not only tweaks the animals’ appetite for sex or food, but also the strength of their preferences for particular foods or mates. Is our preference for pretty faces driven by the same biochemical reward circuit? To find out, researchers invited 30 heterosexual men to browse a series of female faces on a computer (one pictured). Each man received either a dose of the MOR-stimulating drug morphine, the opioid receptor–inhibiting drug naltrexone, or a placebo. The results, published today in Molecular Psychiatry, suggest that we seek out beautiful faces at least in part because our brains reward us. Not only did stimulating MOR neurotransmission cause men to linger longer on faces that they rated as more beautiful, but the beauty rating also became more extreme, with beautiful faces rated as even more attractive relative to the rest of the faces. Inhibiting MOR had the opposite effects. The findings are yet more evidence that our social interactions are strongly influenced by the invisible hand of evolution, pushing us to find attractive mates. But the question remains, how do we decide which face is attractive in the first place? © 2014 American Association for the Advancement of Science
by Bob Holmes Midnight fridge raids are part and parcel of a late-night marijuana smoking session. A study in mice has provided the most complete explanation yet for why a spliff triggers intense hunger pangs. The findings, which elucidate the role of smell, also suggest that we might eventually be able to treat common disorders such as obesity and loss of appetite with a simple nasal spray. We know that the active ingredient in cannabis, THC, binds to cannabinoid receptors in the brain called CB1s. This binding inhibits chemical signals that tell us not to eat, and so make us feel hungry. But this isn't the end of the story. Since smell plays such a central role in making us feel hungry, it must be part of the explanation - but no one knew exactly how it fit. To find out, Giovanni Marsicano of the French research agency INSERM in Bordeaux and his colleagues genetically modified mice to make it possible to turn on and off the CB1 receptor in particular nerve cells within the smell, or olfactory, system. The key proved to be a group of nerve cells that carry signals from the cerebral cortex down to the olfactory bulb, the primary smell centre of the brain. When the team switched off CB1 on these cells, they found that hungry mice no longer ate more than their well-fed counterparts. Conversely, activating CB1 in the same cells by injecting THC caused hungry mice to eat even more. THC-treated mice also responded to less-concentrated food smells than untreated mice, a sign that the chemical had enhanced their sense of smell. © Copyright Reed Business Information Ltd.
By Joel Achenbach, The death last Sunday of Oscar-winning actor Philip Seymour Hoffman at age 46 focused media attention on the nationwide surge in heroin use and overdoses. But the very real heroin epidemic is framed by an even more dramatic increase since the beginning of the century in overdoses from pharmaceutical drugs known as opioids. These are, in effect, tandem epidemics — an addiction crisis driven by the powerful effects on the human brain of drugs derived from morphine. Prescription opioids are killing Americans at more than five times the rate that heroin is, according to the most recent numbers from the Centers for Disease Control and Prevention. These drugs are sold under such familiar brand names as OxyContin, Vicodin and Percocet and can be found in medicine cabinets in every precinct of American society. They’re also sold illicitly on the street or crushed and laced into heroin. There have been numerous efforts by law enforcement agencies to crack down on “pill mills” that dispense massive amounts of the pharmaceuticals, as well as regulations aimed at preventing users from “doctor shopping” to find someone who will write a prescription. Those efforts have had the unintended effect, officials say, of driving some people to heroin in recent years as their pill supply dries up. © 1996-2014 The Washington Post
Keyword: Drug Abuse
Link ID: 19218 - Posted: 02.08.2014