Chapter 4. The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
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Ian Sample Science editor Selling high calorie foods in plain packaging could help in the battle against obesity according to a leading researcher who has won a share of the most lucrative prize in neuroscience for his work on the brain’s reward system. The colourful wrapping and attractive advertising of calorie-rich foods encourage people to buy items that put them at risk of overeating and becoming obese in the future, said Wolfram Schultz, a professor of neuroscience at the University of Cambridge. “We should not advertise, propagate or encourage the unnecessary ingestion of calories,” Schultz said at a press conference held on Monday to announce the winners of the 2017 Brain Prize. “There should be some way of regulating the desire to get more calories. We don’t need these calories.” “Colourful wrapping of high energy foods of course makes you buy more of that stuff and once you have it in your fridge, it’s in front of you every time you open the fridge and ultimately you’re going to eat it and eat too much,” he added. Schultz shares the €1m prize from the Lundbeck Foundation in Denmark with professors Peter Dayan, director of the Gatsby Computational Neuroscience Unit at UCL, and Ray Dolan, director of the Max Planck UCL Centre for Computational Psychiatry and Ageing. Together, the scientists unravelled how the brain uses rewards to learn and shape behaviour.
By Alistair Steele, CBC News The opioid crisis that's claiming lives across the country has taken a particularly sinister turn in the nation's capital. Or so it appears. Much of the public discussion — and a good deal of the news coverage — surrounding the growing number of deaths by opioid overdose in Ottawa has concentrated on the cruel toll the drugs are taking on the city's teenagers, particularly those living in the western suburb of Kanata. The fake prescription pills they take recreationally are cheap and easy to find, but they can also be laced with potentially lethal doses of fentanyl. This tragic trend was given a fresh, young face when Grade 9 student Chloe Kotval, just 14, died from an overdose on Valentine's Day. Police later confirmed pills found near the girl's body contained fentanyl. In a statement released the day of their daughter's funeral, Kotval's parents wrote: "We are concerned about the epidemic nature of the use of high-grade pharmaceuticals amongst young people and their lack of knowledge about them — the consequences of using them are real and terrible." While families have every right to be concerned and to prepare for the worst, there's no evidence showing young people are any more susceptible to opioid overdoses than any other group of drug users in Ottawa. Sean O'Leary, whose own teenage daughter became addicted to counterfeit percocets, told CBC about coming home one night to find a 17-year-old boy who had overdosed in his garage. ©2017 CBC/Radio-Canada.
Recently, an international team of researchers reported that the cerebellum may play a previously unforeseen role in brain alterations associated with the addictive consumption of drugs. Until now, the cerebellum—which has historically been viewed by most neuroscientists as primarily the seat of fine-tuned motor control and coordination—has gone under the radar of drug addiction specialists. The latest reports linking the cerebellum and drug addiction were based on a broad range of groundbreaking research published over the past two years. These findings were recently compiled and featured in two different journals: Neuroscience & Biobehavioral Reviews and the Journal of Neuroscience. Bringing all of this research together was the brainchild of Marta Miquel, professor in the research group Addiction and Neuroplasticity at the Universitat Jaume I (UJI) in Spain. Miguel spearheaded her own original research as well as the initiative to collect multidisciplinary research from a broad spectrum of international institutions and to present these cerebellar findings cohesively under one umbrella. (Cerebellar is the sister word to cerebral and means “relating to or located in the cerebellum.”) In addition to the UJI team, contributing research for this compilation of studies on the cerebellum and addiction came from the University of Cambridge and University of Leeds (United Kingdom); University of Turin (Italy); Universidad Veracruzana (Mexico); the University of Kentucky, Washington State University, and McLean Hospital Translational Neuroscience Laboratory and Mailman Research Center (USA). Psychology Today © 1991-2017 Sussex Publishers, LLC
Keyword: Drug Abuse
Link ID: 23301 - Posted: 03.02.2017
By Jessica Hamzelou Fancy a coffee after that cigarette? Smoking makes you drink more caffeinated drinks, possibly by changing your metabolism so that you break down caffeine quicker, pushing you to drink more to get the same hit. That’s according to Marcus Munafò at the University of Bristol, UK, and his colleagues who have looked into the smoking and drinking habits of about 250,000 people. It’s impossible to do a randomised controlled trial (the most rigorous kind of scientific trial) when it comes to smoking, because it would be unethical to ask a randomly selected group of people to smoke. The next best thing is to study huge biobanks of health data. These biobanks contain information about people’s genes, diets and lifestyles. To explore the relationship between smoking and caffeine, Munafo and his colleagues analysed data from biobanks in the UK, Norway and Denmark. They were particularly interested in people who had inherited a variant of a gene that has already been shown to increase cigarette smoking. The team found that people who had this gene variant also consumed more coffee – but only if they smoked. British people with the same variant also drank more tea, although their Danish and Norwegian counterparts didn’t. This is probably due to cultural differences, says Munafò. “People in Norway and Denmark don’t chain drink tea in the same way that people in the UK do,” he says. © Copyright Reed Business Information Ltd.
Keyword: Drug Abuse
Link ID: 23287 - Posted: 02.27.2017
Allison Aubrey If you drink more alcohol than you want to or should, you're not alone. A nationwide survey by the National Institutes of Health found that 28 percent of adults in the U.S. are heavy drinkers or drink more than is recommended. Yet, most heavy drinkers don't get the help they need. "The biggest problem we have in the field is that less than 10 percent of individuals with an alcohol use disorder get any treatment whatsoever," says George Koob, director of the National Institute on Alcohol Abuse and Alcoholism. Part of the challenge, researchers say, is that many drinkers don't realize that a medicine long used to help people addicted to opioids quit their drug habit can help alcoholics and other heavy drinkers cut back, too. "I thought my only option was AA," John tells NPR. We've agreed to use only his middle name; disclosing his trouble with alcohol publicly, he says, would jeopardize his business. He's a 47-year-old professional who says he started out as a social drinker — a few beers with his softball team after a game. But he sank into a deep depression after several deaths in his family, and sought "solace the bottle," he says. "I wanted to numb my thoughts," says John. He'd often start with hard liquor in the morning, John says, and it wasn't uncommon to have eight drinks or more before the end of the day. © 2017 npr
By Christine Vestal NEW YORK — After a 12-year battle with debilitating abdominal conditions that forced her to stop working, marijuana has helped Lynn Sabulski feel well enough to look for a job. Sabulski is among nearly 14,000 patients in New York state who are certified to use medical marijuana for one of 10 conditions, including her primary diagnosis, inflammatory bowel disease. Marijuana doesn’t address her underlying disease, but it does relieve her painful symptoms. Nationwide, an estimated 1.4 million patients in 28 states and the District of Columbia use legal medical marijuana for a varying list of conditions. A much smaller number of patients in 16 states use limited extracts of the plant, primarily to treat seizure disorders. In the midst of an opioid crisis, some medical practitioners and researchers say they think that greater use of marijuana for pain relief could result in fewer people using the highly addictive prescription painkillers that led to the epidemic. A 2016 study by researchers at Johns Hopkins Bloomberg School of Public Health found that states with medical marijuana laws had 25 percent fewer opioid overdose deaths than states that do not have medical marijuana laws. And another study published in Health Affairs last year found that prescriptions for opioid painkillers such as OxyContin, Vicodin and Percocet paid for by Medicare dropped substantially in states that adopted medical marijuana laws. © 1996-2017 The Washington Post
Geoff Brumfiel When the half-brother of North Korean leader Kim Jong Un collapsed at a Malaysian airport last week, poisoning was instantly suspected. But on Friday, Malaysian authorities revealed that an autopsy had turned up not just any poison, but a rare nerve agent known as VX. VX is among the deadliest chemical weapons ever devised. A colorless, odorless liquid, similar in consistency to motor oil, it kills in tiny quantities that can be absorbed through the skin. A relative of the nerve agent Sarin, VX disrupts communications between nerves and muscles. Victims of VX initially experience nausea and dizziness. Without an antidote, the chemical eventually paralyzes the diaphragm, causing suffocation. That may have been the fate of Kim Jong Nam, the estranged half-brother of North Korea's leader. Security footage showed that Kim was approached by two women who appeared to cover his face with a cloth. Moments later, he fell ill and sought help. He died before reaching a hospital. If the Malaysian analysis is correct and VX was the culprit, that would seem to suggest that the North Korean state itself is behind the killing. "Hardly anybody has it," says Dan Kaszeta, a chemical weapons expert and consultant based in London. The U.S. has destroyed nearly all of its stocks of VX in recent years. North Korea is among the few states in the world that have an active chemical weapons program. It is not a signatory to the Chemical Weapons Convention, which bans the use of such weapons. © 2017 npr
Link ID: 23282 - Posted: 02.25.2017
By Alice Klein The proof is in the packaging. Making all cigarette packets look the same reduces the positive feelings smokers associate with specific brands and encourages quitting, Australian research shows. The findings come ahead of the UK and Ireland introducing plain tobacco packaging in May. Australia was the first nation to introduce such legislation in December 2012. Since then, all cigarettes have been sold in plain olive packets with standard fonts and graphic health warnings. The primary goal was to make cigarettes less appealing so that people would not take up smoking in the first place. But an added bonus has been the number of existing smokers who have ditched the habit. Between 2010 and 2013, the proportion of daily smokers in Australia dropped from 15.1 to 12.8 per cent – a record decline. The number of calls to quit helplines also increased by 78 per cent after the policy change. Brand betrayal This drop in smoking popularity can be partly explained by a loss of brand affinity, says Hugh Webb at the Australian National University in Canberra. People derive a sense of belonging and identity from brands, he says. For example, you may see yourself as a “Mac person” or a “PC person” and feel connected to other people who choose that brand. “Marketers are extremely savvy about cultivating these brand identities.” © Copyright Reed Business Information Ltd
By WINNIE HU Ruth Brunn finally said yes to marijuana. She is 98. She pops a green pill filled with cannabis oil into her mouth with a sip of vitamin water. Then Ms. Brunn, who has neuropathy, settles back in her wheelchair and waits for the jabbing pain in her shoulders, arms and hands to ebb. “I don’t feel high or stoned,” she said. “All I know is I feel better when I take this.” Ms. Brunn will soon have company. The nursing home in New York City where she lives, the Hebrew Home at Riverdale, is taking the unusual step of helping its residents use medical marijuana under a new program to treat various illnesses with an alternative to prescription drugs. While the staff will not store or administer pot, residents are allowed to buy it from a dispensary, keep it in locked boxes in their rooms and take it on their own. From retirement communities to nursing homes, older Americans are increasingly turning to marijuana for relief from aches and pains. Many have embraced it as an alternative to powerful drugs like morphine, saying that marijuana is less addictive, with fewer side effects. For some people, it is a last resort when nothing else helps. Marijuana, which is banned by federal law, has been approved for medical use in 29 states, including New York, and the District of Columbia. Accumulating scientific evidence has shown its effectiveness in treating certain medical conditions. Among them: neuropathic pain, severe muscle spasms associated with multiple sclerosis, unintentional weight loss, and vomiting and nausea from chemotherapy. There have also been reports that pot has helped people with Alzheimer’s disease and other types of dementia as well as Parkinson’s disease. © 2017 The New York Times Company
Jon Hamilton Researchers have created mice that appear impervious to the lure of cocaine. Even after the genetically engineered animals were given the drug repeatedly, they did not appear to crave it the way typical mice do, a team reports in Nature Neuroscience. "They didn't keep going into the room where they received the cocaine and they seemed to be just as happy exploring all around the cage," says Shernaz Bamji, a professor in the Department of Cellular and Physiological Sciences at the University of British Columbia in Vancouver. "Addiction is a form of learning," Bamji says. And somehow, these mice never learned to associate the pleasurable feelings produced by cocaine with the place where they received the drug. The result was startling because the scientists thought these mice would be especially susceptible to addiction. "We repeated the experiment several times to see if we had made a mistake," Bamji says. The reason for the team's surprise had to do with proteins that affect learning. The animals had been genetically engineered to produce high levels of proteins called cadherins in the brain's "reward circuit," which plays an important role in addiction. And genetic studies have suggested that people with high levels of cadherins are more susceptible to drug addiction. Cadherins act a bit like glue, binding cells together. Usually this glue enhances learning by strengthening the connections, or synapses, between brain cells. © 2017 npr
By BENEDICT CAREY The number of retirement-age Americans taking at least three psychiatric drugs more than doubled between 2004 and 2013, even though almost half of them had no mental health diagnosis on record, researchers reported on Monday. The new analysis, based on data from doctors’ office visits, suggests that inappropriate prescribing to older people is more common than previously thought. Office visits are a close, if not exact, estimate of underlying patient numbers. The paper appears in the journal JAMA Internal Medicine. Geriatric medical organizations have long warned against overprescribing to older people, who are more susceptible to common side effects of psychotropic drugs, such as dizziness and confusion. For more than 20 years, the American Geriatrics Society has published the so-called Beers Criteria for potentially inappropriate use, listing dozens of drugs and their mutual interactions. In that time, prescription rates of drugs like antidepressants, sleeping pills and painkillers nonetheless generally increased in older people, previous studies have found. The new report captures one important dimension, the rise in so-called polypharmacy — three drugs or more — in primary care, where most of the prescribing happens. Earlier research has found that elderly people are more likely to be on at least one psychiatric drug long term than younger adults, even though the incidence of most mental disorders declines later in life. “I was stunned to see this, that despite all the talk about how polypharmacy is bad for older people, this rate has doubled,” said Dr. Dilip Jeste, a professor of psychiatry and neurosciences at the University of California, San Diego, who was not involved in the new work. © 2017 The New York Times Company
Richard A. Friedman Psychedelics, the fabled enlightenment drugs of the ’60s, are making a comeback — this time as medical treatment. A recent study claimed that psilocybin, a mushroom-derived hallucinogenic, relieves anxiety and depression in people with life-threatening cancer. Anecdotal reports have said similar things about so-called microdoses of LSD. The allure is understandable, given the limits of our treatments for depression and anxiety. About a third of patients with major depression don’t get better, even after several trials of different antidepressants. But I fear that in our desire to combat suffering, we will ignore the potential risks of these drugs, or be seduced by preliminary research that seems promising. This appears to be the case with the new psilocybin study, which has some serious design flaws that cast doubt on the results (and which the authors mention briefly). The study, done at New York University School of Medicine, examined a very small number of people with cancer in a “crossover” design in which each subject served as her own control, sequentially receiving doses of psilocybin and the control drug niacin, in random order. (Another recent study of psilocybin, done at Johns Hopkins University, used a similar crossover design.) Psilocybin, being a hallucinogen, has immediately recognizable mental effects, so subjects would almost certainly know when they were getting it compared with niacin, a vitamin that causes flushing but has no discernible effect on mood or thinking. This makes it hard to know if subjects got better because of the psilocybin, or because of a placebo effect. The design also means that subjects who got psilocybin first could have had a “carry-over effect” from the drug when they received niacin. In other words, they might still have been under the influence, contaminating the control condition. © 2017 The New York Times Company
By Abigail Zuger, M.D. It was in 2011 that the Centers for Disease Control first drew public attention to the ongoing nationwide opioid crisis. Much earnest commentary has explored the roots of this new killer epidemic since then, focusing on the broad highway between heroin and pain pills, and the online pharmacies, pill mills, and bad-apple doctors who fueled the two-way traffic and enabled catastrophe. Forgive me for rolling my eyes. Anyone with a prescription pad and a shred of common sense saw this whole thing coming down the pike decades ago, a speeding 18-wheeler, tires squealing, no brakes. Furthermore, it has long been clear that while the bad medical apples certainly did their share of damage, there is not a health policy guru or medical school dean in the country whose sins of omission and commission are not also partly responsible. Call it an epidemic of unconscious collusion or, as Dr. Anna Lembke bluntly states, a nation’s doctors “trapped in a system gone mad.” In less than 200 pages, this may be the most important medical book of the decade for finally getting the story of the opioid epidemic exactly right. As far as I am concerned, “Drug Dealer, M.D.,” in less than 200 unassuming, readable, and carefully referenced pages, may be the most important medical book of the decade for finally getting the story of this epidemic exactly right. And it’s not the medical bad apples Lembke is talking about in her title — it’s every doctor in the country. Copyright 2017 Undark
By KATHARINE Q. SEELYE and ABBY GOODNOUGH MANCHESTER, N.H. — Chad Diaz began using heroin when he was 12. Now 36 and newly covered by Medicaid under the Affordable Care Act, he is on Suboxone, a substitute opioid that eases withdrawal symptoms and cravings, and he is slowly pulling himself together. “This is the best my life has gone in many, many years,” Mr. Diaz, a big man wearing camouflage, said as he sat in a community health center here. If Congress and President Trump succeed in dismantling the Affordable Care Act, he will have no insurance to pay for his medication or counseling, and he fears he will slide back to heroin. “If this gets taken from me, it’s right back to Square 1,” he said. “And that’s not a good place. I’m scary when I’m using. I don’t care who I hurt.” As the debate over the fate of the health law intensifies, proponents have focused on the lifesaving care it has brought to people with cancer, diabetes and other physical illnesses. But the law has also had a profound, though perhaps less heralded, effect on mental health and addiction treatment, vastly expanding access to those services by designating them as “essential benefits” that must be covered through the A.C.A. marketplaces and expanded Medicaid. The Center on Budget and Policy Priorities, a left-leaning research group, calculates that 2.8 million people with substance use disorders, including 220,000 with opioid disorders, have coverage under the A.C.A. As the opioid epidemic continues to devastate communities nationwide, public health officials say the law has begun to make a critical difference in their ability to treat and rehabilitate people. © 2017 The New York Times Company
Keyword: Drug Abuse
Link ID: 23215 - Posted: 02.11.2017
By Catherine Offord As an undergraduate at Auburn University in the early 2000s, Jeremy Day was thinking of becoming an architect. But an opportunity to work on a research project investigating reward learning in rodents changed the course of his career. “It really hooked me,” he says. “It made me immediately wonder what mechanisms were underlying that behavior in the animal’s brain.” It’s a question Day has pursued ever since. In 2004, he enrolled in a PhD program at the University of North Carolina at Chapel Hill and began studying neural reward signaling under the mentorship of neuroscientist Regina Carelli. “He was a stellar student by all accounts,” Carelli recalls. “He was very clear on the type of work he wanted to do, even that early on in his career.” Focusing on the nucleus accumbens, a brain region involved in associative learning, Day measured dopamine levels in rats undergoing stimulus-reward experiments. Although a rat’s brain released dopamine on receipt of a reward early in training, Day found that, as the rodent became accustomed to specific cues predicting those rewards, this dopamine spike shifted to accompany the cues instead, indicating a changing role for the chemical during learning.1 Day completed his PhD in 2009, but realized that to better understand dopamine signaling and errors in the brain’s reward system that lead to addiction, he would need a broader skill set. “I had a strong background in systems neuroscience, but my training in molecular neuroscience was not as strong,” he explains. So he settled on “a field that I knew almost nothing about?”—epigenetics—and joined David Sweatt’s lab at the University of Alabama at Birmingham (UAB) as a postdoc. For someone used to a field where “data come in as it’s happening,” Day says, “transitioning to a molecular lab where you might do an assay and you don’t get an answer for a week or two was a culture shock.” © 1986-2017 The Scientist
By SHARON LERNER IN the fall, I began to research an article that I gave the working title “The Last Days of Chlorpyrifos.” A widely used pesticide, chlorpyrifos affects humans as well as the bugs it kills. Back in the halcyon days before the election, the optimism of the title seemed warranted. After years of study, the Environmental Protection Agency had announced in October 2015 that it could no longer vouch for the safety of chlorpyrifos on food. The agency had acknowledged for decades that chlorpyrifos can cause acute poisoning and in the early 2000s it had prohibited its use in most home products and reduced the amounts that could be used on some crops. But the 2015 announcement stemmed from the agency’s recognition of mounting evidence that prenatal exposure to chlorpyrifos could have lasting effects on children’s brains. Though the process of re-evaluating the safety of the pesticide had stretched on for years, at long last, chlorpyrifos seemed to be going down. Another report was expected to provide all the ammunition necessary to stop its use on fruits and vegetables, and I was eager to document its demise. For a reporter who covers the environment, this was going to be the rare happy story. The election of President Trump has thrown that outcome — indeed, the fate of many of the E.P.A.’s public health protections — into question. On Monday, Mr. Trump signed an executive order requiring federal agencies to scrap two regulations for every one they institute on small businesses. In its first week, his administration suspended 30 environmental regulations issued under President Barack Obama. And Myron Ebell, who oversaw the agency’s transition team, suggested recently that the E.P.A.’s staff may soon be reduced by as much as two-thirds. How will the agency’s mission “to protect human health and the environment” fare under this assault? What happens with chlorpyrifos may be our best indication. “I think it’ll be a very early test of their commitment to environmental protection,” Jim Jones, who oversaw the evaluation of chlorpyrifos as the E.P.A.’s assistant administrator for chemical safety and pollution prevention, told me, not long after he stepped down on Inauguration Day. © 2017 The New York Times Company
Hannah Devlin Science correspondent It sounds like torment for the smoker attempting to quit: handling packets of cigarettes and watching footage of people smoking, without being allowed to light up. However, scientists believe that lengthy exposure to environmental triggers for cravings could be precisely what smokers need to help them quit. The technique, known as extinction therapy, targets the harmful Pavlovian associations that drive addiction with the aim of rapidly “unlearning” them. The latest study, by scientists at the Medical University of South Carolina, found that after two one-hour sessions people smoked significantly fewer cigarettes one month after treatment compared to a control group. The study was not an unqualified success – many participants still relapsed after treatment – but the authors believe the work could pave the way for new approaches to treating addiction. Michael Saladin, the psychologist who led the work, said: “When I initially saw the results from this study it was pretty eye-opening.” In smokers, environmental triggers have typically been reinforced thousands of times so that the sight of a lighter, for instance, becomes inextricably linked to the rush of nicotine that the brain has learned will shortly follow. After quitting an addictive substance, these associations fade slowly over time, but people often flounder in the first days and weeks when cravings are most powerful. Saladin and others believe it is possible to fast-track this process in carefully designed training sessions, to help people over the initial hurdle. © 2017 Guardian News and Media Limited
By CATHERINE SAINT LOUIS During her pregnancy, she never drank alcohol or had a cigarette. But nearly every day, Stacey, then 24, smoked marijuana. With her fiancé’s blessing, she began taking a few puffs in her first trimester to quell morning sickness before going to work at a sandwich shop. When sciatica made it unbearable to stand during her 12-hour shifts, she discreetly vaped marijuana oil on her lunch break. “I wouldn’t necessarily say, ‘Go smoke a pound of pot when you’re pregnant,’” said Stacey, now a stay-at-home mother in Deltona, Fla., who asked that her full name be withheld because street-bought marijuana is illegal in Florida. “In moderation, it’s O.K.” Many pregnant women, particularly younger ones, seem to agree, a recent federal survey shows. As states legalize marijuana or its medical use, expectant mothers are taking it up in increasing numbers — another example of the many ways in which acceptance of marijuana has outstripped scientific understanding of its effects on human health. Often pregnant women presume that cannabis has no consequences for developing infants. But preliminary research suggests otherwise: Marijuana’s main psychoactive ingredient — tetrahydrocannabinol, or THC — can cross the placenta to reach the fetus, experts say, potentially harming brain development, cognition and birth weight. THC can also be present in breast milk. “There is an increased perception of the safety of cannabis use, even in pregnancy, without data to say it’s actually safe,” said Dr. Torri Metz, an obstetrician at Denver Health Medical Center who specializes in high-risk pregnancies. Ten percent of her patients acknowledge recent marijuana use. © 2017 The New York Times Company
Elizabeth Eaton Electronic cigarettes may increase the risk of heart disease, researchers at UCLA report. The team found that two risk factors for heart disease were elevated in 16 e-cigarette users compared with 18 nonsmokers. “The pattern was spot-on” for what has been seen in heart attack patients and those with heart disease and diabetes, says cardiologist Holly Middlekauff, a coauthor of the study published online February 1 in JAMA Cardiology. But because the study only looked at a small number of people, the results are not definitive — just two or three patients can skew results, John Ambrose, a cardiologist with the University of California, San Francisco cautions. Plus, he says, some of the e-cigarette users in the study used to smoke tobacco, which may have influenced the data. Even so, Ambrose called the study interesting, noting that “the medical community just doesn’t have enough information” to figure out if e-cigarettes are dangerous. E-cigarette smokers in the study had heartbeat patterns that indicated high levels of adrenaline — also known as epinephrine — in the heart, a sign of heart disease risk. Researchers also found signs of increased oxidative stress, an imbalance of certain protective molecules that can cause the hardening and narrowing of arteries. © Society for Science & the Public 2000 - 2017.
Keyword: Drug Abuse
Link ID: 23180 - Posted: 02.02.2017
Meghan Rosen New X-ray crystallography images reveal how an LSD molecule gets trapped within a protein that senses serotonin, a key chemical messenger in the brain. The protein, called a serotonin receptor, belongs to a family of proteins involved in everything from perception to mood. The work is the first to decipher the structure of such a receptor bound to LSD, which gets snared in the protein for hours. That could explain why “acid trips” last so long, study coauthor Bryan Roth and colleagues report January 26 in Cell. It’s “the first snapshot of LSD in action,” he says. “Until now, we had no idea how it worked at the molecular level.” But the results might not be that relevant to people, warns Cornell University biophysicist Harel Weinstein. Roth’s group didn’t capture the main target of LSD, a serotonin receptor called 5-HT2A, instead imaging the related receptor 5-HT2B. That receptor is “important in rodents, but not that important in humans,” Weinstein says. Roth’s team has devoted decades to working on 5-HT2A, but the receptor has “thus far been impossible to crystallize,” he says. Predictions of 5-HT2A’s structure, though, are very similar to that of 5-HT2B, he says. LSD, or lysergic acid diethylamide, was first cooked up in a chemist’s lab in 1938. It was popular (and legal) for recreational use in the early 1960s, but the United States later banned the drug (also known as blotter, boomer, Purple Haze and electric Kool-Aid). |© Society for Science & the Public 2000 - 201
Keyword: Drug Abuse
Link ID: 23175 - Posted: 02.01.2017