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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
By Chelsea Whyte It was a gruesome scene. The body had severe wounds and was still bleeding despite having been lying for a few hours in the hot Senegalese savanna. The murder victim, a West African chimpanzee called Foudouko, had been beaten with rocks and sticks, stomped on and then cannibalised by his own community. This is one of just nine known cases where a group of chimpanzees has killed one of their own adult males, as opposed to killing a member of a neighbouring tribe. These intragroup killings are rare, but Michael Wilson at the University of Minnesota says they are a valuable insight into chimp behaviour such as male coalition building. “Why do these coalitions sometimes succeed, but not very often? It’s at the heart of this tension between conflict and cooperation, which is central to the lives of chimpanzees and even to our own,” he says. Chimps usually live in groups with more adult females than males, but in the group with the murder it was the other way round. “When you reverse that and have almost two males per every female — that really intensifies the competition for reproduction. That seems to be a key factor here,” says Wilson. Jill Pruetz at Iowa State University, who has been studying this group of chimpanzees in south-eastern Senegal since 2001, agrees. She suggests that human influence may have caused this skewed gender ratio that is likely to have been behind this attack. In Senegal, female chimpanzees are poached to provide infants for the pet trade. Fall from power Thirteen years ago, Foudouko reigned over one of the chimp clans at the Fongoli study site, part of the Fongoli Savanna Chimpanzee Project. As alpha male, he was “somewhat of a tyrant”, Pruetz says. © Copyright Reed Business Information Ltd.
Homa Khaleeli The old saying, “If at first you don’t succeed: try, try again”, might need rewriting. Because, according to new research, even if you do succeed, you should still try, try again. “Overlearning”, scientists say, could be the key to remembering what you have learned. In a study of 183 volunteers, participants were asked to spot the orientation of a pattern in an image. It is a task that took eight 20-minute rounds of training to master. Some volunteers, however, were asked to carry on for a further 16 20-minute blocks to “overlearn” before being moved on to another task. When tested the next day, they had retained the ability better than those who had mastered it and then stopped learning. Primary school encourages pupils to wear slippers in class Read more The lead author of the paper, Takeo Watanabe, a professor of cognitive linguistic and psychological sciences, pointed out that: “If you do overlearning, you may be able to increase the chance that what you learn will not be gone.” But what other tricks can help us learn better? According to researchers at Bournemouth University, children who don’t wear shoes in the classroom not only learn, but behave better. Pupils feel more relaxed when they can kick their shoes off at the door says lead researcher Stephen Heppell, which means they are more engaged in lessons. © 2017 Guardian News and Media Limited
Keyword: Learning & Memory
Link ID: 23173 - Posted: 02.01.2017
By Simon Oxenham Ever felt hungry and angry at the same time? There’s evidence that “hanger” is a real phenomenon, one that can affect your work and relationships. The main reason we become more irritable when hungry is because our blood glucose level drops. This can make it difficult for us to concentrate, and more likely to snap at those around us. Low blood sugar also triggers the release of stress-related hormones like cortisol and adrenaline, as well as a chemical called neuropeptide Y, which has been found to make people behave more aggressively towards those around them. This can all have an alarming effect on how you feel about other people – even those you love. A classic study of married couples asked them to stick pins into “voodoo dolls” that represented their loved ones, to reflect how angry they felt towards them. The volunteers then competed against their spouse in a game, in which the winner could blast loud noise through the loser’s headphones. The researchers tracked the participants’ blood glucose levels throughout. They found that when people had lower sugar levels, the longer the blasts of unpleasant noise they subjected their spouse to, and the more pins they stuck into their dolls. But while being hungry really does change your behaviour, the effects of hanger have sometimes been overstated. One study that attracted attention a few years ago found that judges are less likely to set lenient sentences the closer it gets to lunch. © Copyright Reed Business Information Ltd.
Link ID: 23172 - Posted: 02.01.2017
By SHERI FINK, STEVE EDER and MATTHEW GOLDSTEIN A group of brain performance centers backed by Betsy DeVos, the nominee for education secretary, promotes results that are nothing short of stunning: improvements reported by 91 percent of patients with depression, 90 percent with attention deficit disorder, 90 percent with anxiety. The treatment offered by Neurocore, a business in which Ms. DeVos and her husband, Dick, are the chief investors, consists of showing movies to patients and interrupting them when the viewers become distracted, in an effort to retrain their brains. With eight centers in Michigan and Florida and plans to expand, Neurocore says it has assessed about 10,000 people for health problems that often require medication. “Is it time for a mind makeover?” the company asks in its advertising. “All it takes is science.” But a review of Neurocore’s claims and interviews with medical experts suggest its conclusions are unproven and its methods questionable. Neurocore has not published its results in peer-reviewed medical literature. Its techniques — including mapping brain waves to diagnose problems and using neurofeedback, a form of biofeedback, to treat them — are not considered standards of care for the majority of the disorders it treats, including autism. Social workers, not doctors, perform assessments, and low-paid technicians with little training apply the methods to patients, including children with complex problems. In interviews, nearly a dozen child psychiatrists and psychologists with expertise in autism and attention deficit hyperactivity disorder, or A.D.H.D., expressed caution regarding some of Neurocore’s assertions, advertising and methods. “This causes real harm to children because it diverts attention, hope and resources,” said Dr. Matthew Siegel, a child psychiatrist at Maine Behavioral Healthcare and associate professor at Tufts School of Medicine, who co-wrote autism practice standards for the American Academy of Child and Adolescent Psychiatry. “If there were something out there that was uniquely powerful and wonderful, we’d all be using it.” © 2017 The New York Times Company
Keyword: Learning & Memory
Link ID: 23171 - Posted: 01.31.2017
By Roni Jacobson The psychedelic drug ibogaine is known for two things: its reputation in some circles as a panacea for addiction and the visceral hallucinations it induces. Positive anecdotes abound from people who have sought out the illegal drug at underground clinics. Just one dose, they say, brings near-instant relief from cravings and withdrawal symptoms, a veritable miracle for seemingly intractable addictions. But the side effects of this plant-derived substance can be dangerous or even deadly. Now, with encouraging evidence from animal studies, drugs are being developed to replicate ibogaine's impact on addiction without the side effects. A drug that is chemically related to ibogaine but lacks its hallucinogenic properties is set to begin phase II clinical trials in California early this year. If the results continue to be promising, addiction treatment as we know it could change radically. For decades research on ibogaine has been stymied by its classification as a Schedule I drug, the most tightly regulated category. Yet the results of animal studies have been intriguing. In May 2016 a meta-analysis examining 32 such studies, mostly in mice and rats, found that ibogaine reduced self-administration of cocaine, opioids and alcohol. An earlier study from 2015 found that noribogaine, the substance that ibogaine breaks down to when ingested, reduced self-administration of nicotine in addicted rats by 64 percent. Now Savant HWP, a pharmaceutical company in California, has developed a drug called 18-MC, a compound chemically related to ibogaine, which it hopes will produce the antiaddictive properties without triggering hallucinations. They are betting that the “trip” is not a necessary component of the therapy—an idea shared by some academics. © 2017 Scientific American,
Keyword: Drug Abuse
Link ID: 23170 - Posted: 01.31.2017
James Gorman What fly is famous on TV? Think corpses and detectives wanting to know how long that body has been in a storage locker or suitcase. It’s the blowfly, of course. Its larvae, a.k.a. maggots, feed on rotting flesh, which could be that spouse or business partner who got in the way. Or, in a good police procedural, both the spouse and the business partner, sent to the great beyond together for their transgressions. By seeing whether the eggs have hatched and how big the larvae are, forensic scientists can get an idea of how much time has passed since the victims met their end and began the final chapter in the way of all flesh. By the way, if you have a problem with a spouse or business partner, it’s worth keeping in mind that the flies can indeed get into a suitcase. They stick their ovipositor through the gaps in the zipper. Or the newly hatched larvae themselves can sneak through. But there are aspects of the maggot’s life that have remained somewhat obscure. Martin Hall, a forensic entomologist at the Natural History Museum in London, thought that one part of the fly’s development in particular needed further study. The maggots are a bit like caterpillars in that at a certain point in their development they wrap themselves up in a case and go through one of the most astonishing events in the natural world: metamorphosis. In 10 days, the maggot, which has no legs or eyes and is something like “an animated sock,” Dr. Hall said, turns into the extraordinarily complex blowfly. No doubt blowflies are not as appealing as butterflies to most people, but chalk that up to a human bias for pretty fluttery things that land on flowers. It’s certainly not the fly’s fault. Any close-up image of its multifaceted, jewel-like eye shows that it is marvelous in its own way, even if it does feed on the dead. Science Times © 2017 The New York Times Company
Keyword: Development of the Brain
Link ID: 23169 - Posted: 01.31.2017
Sara Constantino Certain multisensory conditions can alter the experience of bodily ownership. For instance, in the rubber hand illusion, simultaneous visual and haptic inputs lead to the adoption of sensations applied to an artificial limb as one's own. Understanding body ownership, and its malleability, has implications for the development of prosthetics. In a recent paper, Kelly Collins and colleagues at the University of Washington and Karolinska Institute elicited the illusion of ownership of an artificial hand in two epilepsy patients with embedded electrodes through the direct electrical stimulation of the hand area in somatosensory cortex (SI) applied in synchrony with visible touches to a rubber hand. When stimulation was asynchronous or administered to a different SI area, feelings of ownership were no longer induced, stressing the importance of temporal and spatial congruence. They also found that the details of the visual signal (for example, type of touch) affected the sensation. This method extends previous studies by eliciting ownership without stimulation of the peripheral nervous system, which is damaged in patients with spinal cord or nerve lesions. Human–technology mixtures have a long history, with the first known prosthesis, a wooden toe, dating as far back as 950 bc. Today, recent materials, electronics and neuroscience advances are enabling the development of prosthetic limbs that both look and feel real. © 2017 Macmillan Publishers Limited,
Keyword: Pain & Touch
Link ID: 23168 - Posted: 01.31.2017
By JAMES HAMBLIN In 1997, a few hundred people who responded to a job posting in a Pittsburgh newspaper agreed to let researchers spray their nostrils with a rhinovirus known to cause the common cold. The people would then be quarantined in hotel rooms for five days and monitored for symptoms. In return they’d get $800. “Hey, it’s a job,” some presumably said. Compensation may also have come from the knowledge that, as they sat alone piling up tissues, they were contributing to scientific understanding of our social-microbial ecosystem. The researchers wanted to investigate a seemingly basic question: Why do some people get more colds than others? To Gene Brody, a professor at the University of Georgia, the answer was “absolutely wild.” (Dr. Brody is a public-health researcher, so “wild” must be taken in that context.) He and colleagues recently analyzed the socio-economic backgrounds and personalities of the people in the Pittsburgh study and found that those who were “more diligent and tended to strive for success” were more likely than the others to get sick. To Dr. Brody, the implication was that something suffers in the immune systems of people who persevere in the face of adversity. Over the past two years, Dr. Brody and colleagues have amassed more evidence supporting this theory. In 2015, they found that white blood cells among strivers were prematurely aged relative to those of their peers. Ominous correlations have also been found in cardiovascular and metabolic health. In December, Dr. Brody and colleagues published a study in the journal Pediatrics that said that among black adolescents from disadvantaged backgrounds, “unrelenting determination to succeed” predicted an elevated risk of developing diabetes. The focus on black adolescents is significant. In much of this research, white Americans appeared somehow to be immune to the negative health effects that accompany relentless striving. As Dr. Brody put it when telling me about the Pittsburgh study, “We found this for black persons from disadvantaged backgrounds, but not white persons.” © 2017 The New York Times Company
Noah Charney The Chinese government just arrested a group of people associated with a sham tourist attraction that had lured hundreds of sight-seers to a fake Terracotta Warriors exhibit, comprised entirely of modern replicas. Sotheby’s recently hired Jamie Martin of Orion Analytical, a forensic specialist at testing art, who then discovered that a Parmigianino painting recently sold is actually a modern forgery (Sotheby’s returned the buyer’s money and then sued the person for whom they sold it). And the Ringling Museum in Sarasota, Florida, is hoping that a painting of Philip IV of Spain in their collection will be definitively determined to be by Velazquez, and not a copy in the style of Velazquez. And that’s just in the last week or so. Art forgery and authenticity seems to be in the news just about every week (to my publicist’s delight). But I’m on a bit of a brainstorm. After my interview with Nobel Prize winner Dr. Eric Kandel on the neuroscience behind how we humans understand art, I’ve developed a keen interest in art and the mind. I tackled selfies, self-portraits and facial recognition recently, as well as what happens when the brain fails to function properly and neglects to recognize the value of art. Since my last book was a history of forgery, it was perhaps inevitable that I would wonder about the neurology of the recognition of originals versus copies. But while I looked into forgery from a wide variety of angles for the book, neuroscience was not one of them. © 2017 Salon Media Group, Inc.
By ADAM BEAR and JOSHUA KNOBE What’s normal? Perhaps the answer seems obvious: What’s normal is what’s typical — what is average. But in a recent paper in the journal Cognition, we argue that the situation is more complicated than that. After conducting a series of experiments that examined how people decide whether something is normal or not, we found that when people think about what is normal, they combine their sense of what is typical with their sense of what is ideal. Normal, in other words, turns out to be a blend of statistical and moral notions. Our key finding can be illustrated with a simple example. Ask yourself, “What is the average number of hours of TV that people watch in a day?” Then ask yourself a question that might seem very similar: “What is the normal number of hours of TV for a person to watch in a day?” If you are like most of our experimental participants, you will not give the same answer to the second question that you give to the first. Our participants said the “average” number was about four hours and the “normal” number was about three hours. In addition, they said that the “ideal” number was about 2.5 hours. This has an interesting implication. It suggests that people’s conception of the normal deviates from the average in the direction of what they think ought to be so. Our studies found this same pattern in numerous other cases: the normal grandmother, the normal salad, the normal number of students to be bullied in a middle school. Again and again, our participants did not take the normal to be the same as the average. Instead, what people picked out as the “normal thing to do” or a “normal such-and-such” tended to be intermediate between what they thought was typical and what they thought was ideal. © 2017 The New York Times Company
Link ID: 23165 - Posted: 01.30.2017
Bruce Bower Hunter-gatherers and farming villagers who live in worlds without lightbulbs or thermostats sleep slightly less at night than smartphone-toting city slickers, researchers say. “Contrary to conventional wisdom, people in societies without electricity do not sleep more than those in industrial societies like ours,” says UCLA psychiatrist and sleep researcher Jerome Siegel, who was not involved in the new research. Different patterns of slumber and wakefulness in each of these groups highlight the flexibility of human sleep — and also point to potential health dangers in how members of Western societies sleep, conclude evolutionary biologist David Samson of Duke University and colleagues. Compared with other primates, human evolution featured a shift toward sleeping more deeply over shorter time periods, providing more time for learning new skills and knowledge as cultures expanded, the researchers propose. Humans also evolved an ability to revise sleep schedules based on daily work schedules and environmental factors such as temperature. Samson’s team describes sleep patterns in 33 East African Hadza hunter-gatherers over a total of 393 days in a paper published online January 7 in the American Journal of Physical Anthropology. The team’s separate report on slumber among 21 rural farmers in Madagascar over 292 days will appear later this year in the American Journal of Human Biology. |© Society for Science & the Public 2000 - 201
By Andrew Joseph, Public health officials on Thursday said they had detected a bizarre cluster of cases in which patients in Massachusetts developed amnesia over the past few years — a highly unusual syndrome that could be connected to opioid use. The officials have identified only 14 cases so far. But officials said it’s possible that clinicians have simply missed other cases. The patients were all relatively young — they ranged in age from 19 to 52. Thirteen of the 14 patients identified had a substance use disorder, and the 14th patient tested positive for opioids and cocaine on a toxicology screen. “What we’re concerned about is maybe a contaminant or something else added to the drug might be triggering this,” said Dr. Alfred DeMaria, the state epidemiologist at the Massachusetts Department of Public Health and an author of the new report. “Traditionally there’s no evidence that the drugs themselves can do this.” The pattern emerged when Dr. Jed Barash, a neurologist at Lahey Hospital and Medical Center in Burlington, Mass., reported four of the amnesia cases to the state’s public health department. The department then sent out an alert to specialists, including neurologists and emergency physicians, asking about similar cases, ultimately identifying 10 more from 2012 to 2016 at hospitals in eastern Massachusetts. (The patients included one person who lived in New Hampshire and one person who was visiting Massachusetts from Washington state.) © 2017 Scientific American,
Erin Hare One chilly day in February 1877, a British cotton baron named Joseph Sidebotham heard what he thought was a canary warbling near his hotel window. He was vacationing with his family in France, and soon realized the tune wasn’t coming from outside. “The singing was in our salon,” he wrote of the incident in Nature. “The songster was a mouse.” The family fed the creature bits of biscuit, and it quickly became comfortable enough to climb onto the warm hearth at night and regale them with songs. It would sing for hours. Clearly, Sidebotham concluded, this was no ordinary mouse. More than a century later, however, scientists discovered he was wrong. It turns out that all mice chitter away to each other. Their language is usually just too high-pitched for human ears to detect. Today, mouse songs are no mere curiosity. Researchers are able to engineer mice to express genetic mutations associated with human speech disorders, and then measure the changes in the animals’ songs. They’re leveraging these beautifully complex vocalizations to uncover the mysteries of human speech. Anecdotal accounts of singing mice date back to 1843. In the journal The Zoologist, the British entomologist and botanist Edward Newman wrote that the song of a rare “murine Orpheus” sounds as “if the mouth of a canary were carefully closed, and the bird, in revenge, were to turn ventriloquist, and sing in the very centre of his stomach.” © 2017 by The Atlantic Monthly Group.
By Roni Caryn Rabin Neuromas of the foot, a painful condition caused by an inflamed nerve in the ball of the foot, can be effectively treated at home with daily massage and stretches and over-the-counter painkillers, said Dr. Jacqueline Sutera, a doctor of podiatric medicine and surgery. “Of all the patients with neuromas I see in the office, I would say that ultimately only two of 10 might need surgery,” said Dr. Sutera, who practices in New York City and New Jersey. Neuromas of the foot, also known as Morton's neuromas, typically cause sharp, stabbing pain in the second, third and fourth toes. The goal of massaging and stretching is to open up the space between the bones — the metatarsals — in the ball of the foot and increase circulation, which can help reduce the pain and inflammation. Focus on the ball of the foot, not the toes, since the pain in the toes is referred pain from the ball of the foot. Dr. Sutera recommends placing the thumbs at the top of the foot and the other fingers on the bottom of the foot — or vice versa — and pressing and massaging the bones of the ball of the foot, “creating pressure on both sides, top and bottom.” Follow massages with stretches, using your hands to “grab your forefoot and pull it apart so you’re stretching the spaces between the metatarsals in the ball of the foot.” Massages and stretches are most effective at the end of the day, she said, ideally after a hot shower, bath or other heat application. After the massage and stretching, the area should be iced. © 2017 The New York Times Company
Keyword: Pain & Touch
Link ID: 23161 - Posted: 01.28.2017
By Matt Blois Some of the signals animals use to communicate are obvious. Birds sing. Lions roar. But there’s a whole category of signals in the natural world that humans rarely notice. Researchers have found that one species of cichlid uses urine to send chemical signals to rivals during aggressive displays. The team separated large fish from small fish with a transparent divider. Half the dividers contained holes to allow water to flow back and forth. The scientists then injected the fish with a violet dye (pictured), turning their urine bright blue. When the animals saw each other, they raised their fins and rushed toward the divider. They also changed the way they peed. Fish separated by a solid barrier couldn’t detect their opponent’s urine. In an attempt to get their message across, they urinated even more. Without the chemical cues provided by the urine, smaller fish often tried to attack their larger opponents, the team reports this month in Behavioral Ecology and Sociobiology. Humans could be missing other signals as well, the researchers contend. In addition to chemical signals, animals use seismic vibrations, electricity, and ultraviolet light to communicate. Visual signals might be more obvious, but this research stresses the importance of looking for less noticeable forms of communication, the authors say. © 2017 American Association for the Advancement of Science.
Keyword: Chemical Senses (Smell & Taste)
Link ID: 23160 - Posted: 01.28.2017
By NICHOLAS BAKALAR Psychological distress may increase your chances of dying from cancer. Researchers interviewed 163,363 adults in England and Scotland using well-validated questionnaires on general and mental health. They followed the population in 16 studies conducted between 1994 and 2008. After controlling for age, smoking, physical activity and other factors, they found that compared with those with the lowest scores on depression and anxiety, those with the highest had higher rates of cancer death. The associations were particularly strong for colon and rectal, prostate, pancreatic and esophageal cancers, and for leukemia. In instances of colorectal and prostate cancer, they found a “dose-response” effect: the greater the distress, the greater the likelihood of death from those cancers. People might have had undiagnosed cancer at the start of the study, which would affect their mood, so the researchers accounted for this possibility by doing an analysis that excluded study members who died of cancer in the first five years. The results were largely the same. The study, in BMJ, is observational so cannot determine cause and effect, and it depended in part on self-reports. “The extent to which these associations could be causal,” the authors write, “requires further testing with alternative study designs.” © 2017 The New York Times Company
By Emily Underwood LOS ANGELES, CALIFORNIA—In a barbed wire–enclosed parking lot 100 meters downwind of the Route 110 freeway, an aluminum hose sticks out of a white trailer, its nozzle aimed at an overpass. Every minute, the hose sucks up hundreds of liters of air mixed with exhaust from the roughly 300,000 cars and diesel-burning freight trucks that rumble by each day. Crouched inside the trailer, a young chemical engineer named Arian Saffari lifts the lid off a sooty cylinder attached to the hose, part of a sophisticated filtration system that captures and sorts pollutants by size. Inside is a scientific payload: particles of sulfate, nitrate, ammonium, black carbon, and heavy metal at least 200 times smaller than the width of a human hair. The particles are too fine for many air pollution sensors to accurately measure, says Saffari, who works in a lab led by Constantinos Sioutas at the University of Southern California (USC) here. Typically smaller than 0.2 µm in diameter, these “ultrafine” particles fall within a broader class of air pollutants commonly referred to as PM2.5 because of their size, 2.5 µm or less. When it comes to toxicity, size matters: The smaller the particles that cells are exposed to, Saffari says, the higher their levels of oxidative stress, marked by the production of chemically reactive molecules such as peroxides, which can damage DNA and other cellular structures. © 2017 American Association for the Advancement of Science.
Amy Maxmen The acid tests of 1960s San Francisco have morphed into something quite different in today’s Silicon Valley. Mind-altering trips have given way to subtle productivity boosts purportedly caused by tiny amounts of LSD or other psychedelic drugs. Fans claim that this ‘microdosing’ boosts creativity and concentration, but sceptics doubt that ingesting or inhaling one-tenth of the normal dose could have an effect. Science could soon help to settle the matter. Researchers have finally mapped the 3D structure of LSD in its active state — and the details, published today in Cell1, indicate the key to the chemical’s potency1. Another team reports today in Current Biology2 that it has pinpointed the molecular go-between that creates the perception of deep meaning experienced during acid trips — a feeling that the writer Aldous Huxley once described as “solidarity with the Universe”. “This is what we dreamed of doing when I was a graduate student in the seventies,” says Gavril Pasternak, a pharmacologist at Memorial Sloan Kettering Cancer Center in New York City who has spent decades studying the receptor proteins in the brain that mediate the activity of opioids and psychedelic drugs. “Work like this expands our understanding of how these receptors work.” In 1972, researchers revealed LSD’s shape by mapping the arrangement of atoms in its crystallized form3. But in the decades since, they’ve struggled to reveal the crystal structure of a receptor grasping a molecule of LSD or another psychedelic drug. This active configuration is key to understanding how drugs work, because their action depends on how they cling to molecules in the body. © 2017 Macmillan Publishers Limited,
By Anil Ananthaswamy People with post-traumatic stress disorder often get flashbacks that can be triggered by an innocuous smell or sound. Now a study that linked unrelated memories and separated them again, suggests that one day we may be able to decouple memories and prevent flashbacks in people with PTSD. Individual memories are stored in groups of neurons – an idea first proposed by psychologist Donald Hebb in 1949. Only now are we developing sophisticated techniques for examining these ensembles of neurons. To see whether two independent memories can become linked, Kaoru Inokuchi at the University of Toyama in Japan, and colleagues used a standard method for creating memories in mice. When mice are exposed to pain, they can learn to link this with associated stimuli, a taste, for example. The team trained mice to form two separate fear memories. First, the mice learned to avoid the sugary taste of saccharine. Whenever they licked a bottle filled with saccharine solution, they were injected with lithium chloride, which induces nausea. Disconnecting memories A few days later, the same mice were taught to associate a tone with a mild electric shock. This caused the mice to freeze whenever they heard it, even if it wasn’t followed with a shock. They remembered the tone as a traumatic experience. © Copyright Reed Business Information Ltd.