Beth Darnall Last month, the US National Institutes of Health (NIH) formally launched a multi-agency effort to combat the country’s opioid-addiction crisis. Funds for research into controlling opioid misuse and treating pain will nearly double in 2018, to US$1.1 billion. The forces behind this epidemic extend beyond overprescription: most of the tens of thousands of deaths caused by opioid overdose in the United States each year result from illicit use. Still, an inadequate understanding about how to treat pain has certainly contributed. We need to characterize patients better, and we need more studies that incorporate non-drug treatments alongside any form of medication. Consider this crucial question: what is the first treatment you should give a person for chronic pain, or even many acute injuries? Most clinicians now agree that the answer should not be opioids. Fewer recognize that the question is not which pill to use instead, but what system of interventions — including medication — and monitoring to implement. Too often, pain is treated as a purely biomedical problem. It is a biopsychosocial condition. Psychological treatment can be combined with medication to equip people with the tools to better control their pain experience. Psychological therapies can also lower risks such as addiction, because the emphasis is on engaging patients in managing their daily actions to help themselves to feel better in the long run, rather than relying solely on passive medications. Yet a common clinical practice is to recommend such psychosocial strategies for pain only after all medications have failed. © 2018 Macmillan Publishers Limited,

Keyword: Pain & Touch
Link ID: 24935 - Posted: 05.03.2018

By NICHOLAS BAKALAR Taking saunas may reduce the risk for stroke. Researchers studied 1,628 men and women aged 53 to 74, free of stroke at the start. They had data on body mass index, alcohol consumption, smoking, blood pressure, blood lipid levels, and other health and behavioral characteristics that affect cardiovascular health. The participants reported how often they took traditional Finnish saunas and how long they stayed in the sauna, and the researchers followed them for an average of 15 years. There were 155 strokes over the period. The study is in the journal Neurology. After adjusting for other variables, they found that compared with people who took saunas once a week, those who took them two to three times weekly were 12 percent less likely to have a stroke. People who took saunas four to seven times a week reduced their risk for stroke by 62 percent. Although the researchers found a strong effect independent of other variables, the study was observational and cannot prove causality. Still, there are plausible reasons saunas might be protective. “Temperature increases, even of 1 or 2 degrees Celsius, can limit inflammatory processes in the body and reduce arterial stiffness,” said the senior author, Dr. Jari A. Laukkanen, a professor of medicine at the University of Eastern Finland. “It’s possible that steam rooms or hot tubs could produce similar results.” © 2018 The New York Times Company

Keyword: Stroke
Link ID: 24934 - Posted: 05.03.2018

Jake Harper To the untrained, the evidence looks promising for a new medical device to ease opioid withdrawal. A small study shows that people feel better when the device, an electronic nerve stimulator called the Bridge, is placed behind their ear. The company that markets the Bridge is using the study results to promote its use to anyone who will listen: policymakers, criminal justice officials and health care providers. The message is working. In the face of a nationwide crisis of opioid addiction, people are eager for new solutions. Criminal justice officials in multiple states have started Bridge pilot programs. At least one such program in Indiana received state funds. Providers with a major hospital chain in Indiana began prescribing the Bridge. And politicians in Indiana, Utah and Ohio publicly touted the device. Innovative Health Solutions, the device maker, has marketed the Bridge for opioid withdrawal for more than a year, even before it had clearance for that use from the Food and Drug Administration. Then, last November, the Versailles, Ind.-based company got that, too. Citing the study, the FDA allowed the Bridge to be promoted for opioid withdrawal. Indiana State Sen. Jim Merritt, a Republican who is known for sponsoring legislation addressing the opioid crisis, held an effusive press conference after the FDA gave its OK to the Bridge. "People will detox," he told reporters. "They will withdraw from drugs if it's a simpler process, and this is it." © 2018 npr

Keyword: Drug Abuse
Link ID: 24933 - Posted: 05.02.2018

By Dana G. Smith You don’t remember it, but you woke up at least 100 times last night. These spontaneous arousals, lasting less than 15 seconds each, occur roughly every five minutes and don’t seem to affect how well-rested you feel. They are unrelated to waking up from a bad dream or your partner tossing and turning. Instead, they seem to be linked to some internal biological mechanism. Frequently waking up throughout the night may have protected early humans from predators by increasing their awareness of their surroundings during sleep. “The likelihood someone would notice an animal is higher [if they] wake up more often,” says Ronny Bartsch, a senior lecturer in the Department of Physics at Bar-Ilan University in Israel. “When you wake up, you’re more prone to hear things. In deep sleep, you’re completely isolated.” Sleep scientists, however, have been stumped as to what triggers these nocturnal disruptions. In a new Science Advances paper Bartsch proposes an innovative hypothesis that spontaneous arousals are due to random electrical activity in a specific set of neurons in the brain—aptly named the wake-promoting neurons. Even when you are asleep your brain cells continuously buzz with a low level of electrical activity akin to white noise on the radio. Occasionally, this electrical clamor reaches a threshold that triggers the firing of neurons. The new paper suggests that when random firing occurs in the wake-promoting neurons, a person briefly jerks awake. But this is countered by a suite of sleep-promoting neurons that helps one quickly fall back to sleep. © 2018 Scientific American

Keyword: Sleep
Link ID: 24932 - Posted: 05.02.2018

Nicola Davis MDMA, the main ingredient of the party drug ecstasy, could help reduce symptoms among those living with post-traumatic stress disorder, research suggests. Post-traumatic stress disorder is commonly treated with drugs, psychotherapies or both. However, some find little benefit, with certain talking therapies linked to high dropout rates. Now scientists have released the latest of several small studies showing that MDMA, when combined with talking therapies, could prove effective in reducing symptoms. “It is thought that the MDMA is catalysing the therapy, [rather than] just being effective on its own,” said Dr Allison Feduccia, co-author of the research by the MAPS Public Benefit Corporation, a US-based charity focused on research into MDMA and psychotherapy, which funded the study. Feduccia added that MDMA affected levels of certain chemicals in the brain and helped individuals become more emotionally engaged in the therapy. The study is one of six that has led the US Food and Drug Administration (FDA) to designate MDMA as a “breakthrough therapy” for PTSD and approve the next stage of clinical trials – so called “phase three”– which must be passed before the approach can be made available to patients. “We’re starting the first phase three trial [this month],” said Feduccia. © 2018 Guardian News and Media Limited

Keyword: Stress; Drug Abuse
Link ID: 24931 - Posted: 05.02.2018

By GRETCHEN REYNOLDS Small amounts of exercise could have an outsize effect on happiness. According to a new review of research about good moods and physical activity, people who work out even once a week or for as little as 10 minutes a day tend to be more cheerful than those who never exercise. And any type of exercise may be helpful. The idea that moving can affect our moods is not new. Many of us would probably say that we feel less cranky or more relaxed after a jog or visit to the gym. Science would generally agree with us. A number of past studies have noted that physically active people have much lower risks of developing depression and anxiety than people who rarely move. But that research centered on the relationships between exercise and psychological problems like depression and anxiety. Fewer past studies explored links between physical activity and upbeat emotions, especially in people who already were psychologically healthy, and those studies often looked at a single age group or type of exercise. On their own, they do not tell us much about the amounts or types of exercise that might best lift our moods, or whether most of us might expect to find greater happiness with regular exercise or only certain groups of people. So for the new review, which was published last month in The Journal of Happiness Studies, researchers at the University of Michigan decided to aggregate and analyze multiple past studies of working out and happiness. © 2018 The New York Times Company

Keyword: Depression
Link ID: 24930 - Posted: 05.02.2018

Nicola Davis Brain tumour research is to get an £18 million injection of funding to aid projects ranging from exploring how such cancers begin to developing new ways to treat them. More than 250,000 people worldwide, including 11,400 people in the UK alone, are diagnosed with a brain tumour every year and often the prognosis is bleak. According to Cancer Research UK figures, just 14% of those diagnosed survive for 10 years or more, while less than 1% of brain tumours are preventable. The disease was recently thrown into the spotlight after Tessa Jowell, the former Labour minister, revealed she has terminal brain cancer. Among the reasons why treatments have proved elusive, experts say, are that brain tumours show a lot of variation from person to person, are often diagnosed at an advanced stage, and are often resistant to treatments used for other cancers, with the blood-brain barrier also preventing some drugs from reaching the cancer. Also, as the cancer is in the brain, it is not possible to remove large amounts of tissue during surgery. “The human brain has about 100bn neurons and each of those neurons connects to tens of thousands of other neurons – it is incredibly complex,” said Dr Iain Foulkes, CRUK’s executive director of research and innovation. “What we are trying to do here is understand one of the most complex diseases known to humankind, which is cancer, in the most complex of organs. So it is a big challenge.” © 2018 Guardian News and Media Limited

Keyword: Miscellaneous
Link ID: 24929 - Posted: 05.02.2018

By Roni Dengler Hoary bats are habitual squawkers. Sporting frosted brown fur á la Guy Fieri, the water balloon–size bats bark high-pitched yips to navigate the dark night sky by echolocation. But a new study reveals that as they fly, those cries often drop to a whisper, or even silence, suggesting the bats may steer themselves through the darkness with some of the quietest sonar on record. To find out how hoary bats navigate, researchers used infrared cameras and ultrasonic microphones to record scores of them flying through a riverside corridor in California on five autumn nights. In about half of the nearly 80 flights, scientists captured a novel type of call. Shorter, faster, and quieter than their usual calls, the new “micro” calls use three orders of magnitude less sound energy than other bats’ yaps did, the researchers report today in the Proceedings of the Royal Society B. As bats approached objects, they would often quickly increase the volume of their calls. But in close to half the flights, researchers did not pick up any calls at all. This stealth flying mode may explain one sad fact of hoary bat life: They suffer more fatal run-ins with wind turbines than other bat species in North America. The microcalls are so quiet that they reduce the distance over which bats can detect large and small objects by more than three times. That also cuts bats’ reaction time by two-thirds, making them too slow to catch their insect prey. © 2018 American Association for the Advancement of Science

Keyword: Hearing
Link ID: 24928 - Posted: 05.02.2018

Helen Thompson In the pitch-black waters beneath the Arctic ice, bowhead whales get funky. A small population of endangered bowheads belt an unusually varied repertoire of songs, which grows more diverse during mating season. Hunted to near extinction in the 1600s, these fire truck–sized mammals now number in the 300s in the frigid waters around the Svalbard archipelago in Norway. Underwater audio recorders captured the whales singing 184 acoustically distinct songs from October to April in 2010 through 2014. On the bowhead charts, a song's popularity is fleeting. Most recorded songs were heard for less than 100 hours total, although one song registered over 730 hours total. Some songs appeared in more than one month, but none repeated annually. December and January, likely the height of breeding season, saw a wider array of new bowhead songs than other months, researchers report in the April Biology Letters. Hearing a more distinct mixtape may play a role in enticing a female to mate. A hot cetacean band The Spitzbergen bowhead whale songbook contains a wide variety of tunes, and some stick around on the charts longer than others. Here each bubble corresponds to one of the 184 songs recorded by researchers from 2010 to 2014. The size of the bubble corresponds to the number of hours it was sung. Click on any of the dark green bubbles to hear that whale’s song. Groups of humpback whales don't change their tunes much in a given year, compared with bowheads. Only a few songbird species boast similar diversity. © Society for Science & the Public 2000 - 2018.

Keyword: Animal Communication; Sexual Behavior
Link ID: 24927 - Posted: 05.01.2018

by Eli Rosenberg At least a dozen and a half people have been diagnosed with a rare form of eye cancer in two locations in North Carolina and Alabama, leaving medical experts mystified about the cause. Ocular melanoma occurs in about 6 out of every 1 million people, according to CBS News, and at least 18 people who have been diagnosed with the eye cancer have connections to Huntersville, N.C., Auburn, Ala., or both locations. Marlana Orloff, an oncologist at Thomas Jefferson University in Philadelphia, is studying the cases with her colleagues, according to CBS. “Most people don’t know anyone with this disease,” Orloff said. “We said, 'Okay, these girls were in this location, they were all definitively diagnosed with this very rare cancer — what’s going on?’ ” Alabama health officials have declined to call the outbreak a cluster yet. Three friends, Juleigh Green, Allison Allred and Ashley McCrary, are among those who have been treated for the cancer, and two of them, Green and Allred, had to get an eye removed. “What’s crazy is literally standing there, I was like, ‘Well, I know two people who’ve had this cancer,’ ” McCrary said. Many of the patients are now traveling to Philadelphia for treatment. The cancer has presented complications for some of the patients, CBS reported. Lori Lee, an Auburn University graduate, had the cancer metastasize in her liver. © 1996-2018 The Washington Post

Keyword: Vision
Link ID: 24926 - Posted: 05.01.2018

By Kerry Grens Neena Schwartz, a reproductive biologist at Northwestern University who discovered the hormone inhibin and its role in the regulation of reproductive cycles, died this month (April 15). She was 91. “She was a tremendous scientist, a pioneer for women in the sciences, and a leader in our discipline of endocrinology,” Teresa Woodruff and Kelly Mayo, both of Northwestern University, write in a memorial in Endocrine News. Among numerous leadership roles throughout her career, Schwartz founded the American Women in Science (AWIS) in 1971 and was a president of the Endocrine Society in the early 1980s. Schwartz was born in Baltimore, earned her undergraduate degree from Goucher College, and received her doctorate from Northwestern University in 1953. After a faculty position at the University of Illinois College of Medicine, she joined Northwestern in 1973 and remained as a professor there until her retirement in 1999. Her early work focused on rats’ hormonal cycles, and the insight she derived from her studies contributed to a basic understanding of the so-called HPG axis, the hypothalamic-pituitary-gonadal crosstalk of hormones that controls reproduction. Schwartz later discovered a peptide-based feedback system controlling hormone levels in the ovaries, and described the hormone inhibin, which blocks follicle stimulating hormone (FSH). The presence of inhibin had been proposed decades earlier, but nobody had searched for it in the follicle fluid of ovaries—until Schwartz and her colleague at the University of Maryland, Cornelia Channing took up the cause. Channing had sent Schwartz the fluid, and Schwartz found that it made FSH levels drop. © 1986-2018 The Scientist

Keyword: Hormones & Behavior
Link ID: 24925 - Posted: 05.01.2018

Jon Hamilton Military personnel may be endangering their own brains when they operate certain shoulder-fired weapons, according to an Army-commissioned report released Monday. The report, from the Center for a New American Security, says these bazooka-like weapons pose a hazard because they are powered by an explosion just inches from the operator's head. "When you fire it, the pressure wave feels like getting hit in the face," says Paul Scharre, a former Army Ranger who directs the technology and national security program at the Center. Scharre is a co-author of the center's report: Protecting Warfighters from Blast Injury. The report looks at a range of injuries caused by blast waves — pulses of high pressure air that emanate from an explosion and travel faster than the speed of sound. During the wars in Iraq and Afghanistan, military officials recognized that the blast wave from a roadside bomb could damage a person's brain without leaving any visible sign of injury. And in 2010, the Pentagon issued a memo outlining steps to improve care of troops exposed to these explosions. Since then, there's been growing evidence that blasts from weapons like the Carl Gustav recoilless rifle and the AT4 anti-tank weapon can also affect the brain. S © 2018 npr

Keyword: Brain Injury/Concussion
Link ID: 24924 - Posted: 04.30.2018

Edward Bullmore Depression runs in families, we know. But it is only very recently, and after considerable controversy and frustration, that we are beginning to know how and why. The major scientific discoveries reported last week by the Psychiatric Genomics Consortium in Nature Genetics are a hard-won breakthrough in our understanding of this very common and potentially disabling disorder. If your parents have been depressed, the chances that you have been or will be depressed are significantly increased. The background risk of depression in the general population is about one in four – each of us has a 25% chance of becoming depressed at some point in our lives. And if your parents have been depressed, your risk jumps by a factor of three. However, controversy has long swirled around the question of nature or nurture. Is the depressed son of a depressed mother the victim of her inadequate parenting and the emotionally chilly, unloving environment she provided during the early years of his life? Or is he depressed because he inherited her depressive genes that biologically determined his emotional fate, regardless of her parenting skills? Is it nature or nurture, genetics or environment, which explain why depression runs in families? In the 20th century, psychiatrists ingeniously teased out some answers to these questions. For example, it was found that pairs of identical twins, with 100% identical DNA, were more likely to have similar experiences of depression than were pairs of non-identical twins, with 50% identical DNA. This indicated clearly that depression is genetically heritable. But well into the 21st century, the precise identity of the “genes for depression” remained obscure. Since 2000, there has been a sustained international research effort to discover these genes, but the field has been bedevilled by false dawns and inconsistent results. © 2018 Guardian News and Media Limited

Keyword: Depression; Genes & Behavior
Link ID: 24923 - Posted: 04.30.2018

By Kirstie Brewer BBC News People might think battling obesity is down to sheer willpower, but medical research says otherwise. Here are five potentially surprising factors that can affect your weight, as unearthed by The Truth About Obesity . 1. Gut microbes Gillian and Jackie are twins - but one weighs over six stone (41kg) more than the other. Prof Tim Spector has been tracking their progress over 25 years, as part of the Twins Research UK study. He believes a lot of their weight differences are down to the tiny organisms - microbes - that live deep in the gut. "Every time you eat anything, you're feeding a hundred trillion microbes. You're never dining alone," he says. A stool sample from each twin revealed Gillian, the thinner of the two, had a very diverse range of microbes, whereas Jackie had very few species living in her gut. "The greater the diversity, the skinnier the person. If you're carrying too much weight, your microbes aren't as diverse as they should be," says Prof Spector, who found the same pattern in a study of 5,000 people. Image copyright Science Photo Library Having a healthy and varied diet, rich in different sources of fibre, has been shown to create a more diverse range of gut microbes. Prof Spector warns most Britons eat only half the fibre they should. 2. The gene lottery Why do some people diligently follow diets and exercise regularly but still struggle to see results, while others do very little and don't pile on the pounds? Scientists at Cambridge University believe 40-70% of the effect on our weight is down to variation in the genes we inherit. © 2018 BBC

Keyword: Obesity
Link ID: 24922 - Posted: 04.30.2018

By Neuroskeptic | I’ve been thinking lately about the question of what leads scientists to choose a discipline. Why does someone end up as a chemist rather than a biologist? A geneticist as opposed to a cognitive neuroscientist? We might hope that people choose their discipline based on an understanding of what doing research in each discipline involves, but I don’t think this often happens. I know it didn’t happen in my case. Here, then, is how I became a neuroscientist. As far back as I can remember, I had always wanted to be a scientist. As a young child there was no doubt in my mind about that. But back then I didn’t know what kind of science I was most interested in. I didn’t even know that I would eventually have to pick one. When I got to high school, I did well in both chemistry and biology, and I enjoyed studying both. (The less said about physics the better). But it was biology that really held my attention. Chemistry, it seemed to me, was pretty much finished. The big discoveries had all been made already. Only biology was still a work in progress. I realize now that this was a superficial view, but that was how I saw it at 17. So biology it was. But which kind of biology? Here, I didn’t really have a clue. When I arrived at university, I thought vaguely that my future lay in some kind of molecular biology. I dreamed of curing cancer or malaria one day. But this dream did not survive my first year classes in biochemistry and cell biology, which I found dry and, like chemistry, just too well understood. However many lives might be saved by finding out which gene codes for which protein, I couldn’t see myself being interested in this, so I callously abandoned my plan to save the world.

Keyword: Miscellaneous
Link ID: 24921 - Posted: 04.30.2018

Carl Zimmer Nine years later, Erin Wessling can still remember the first time she visited Fongoli, a savanna in southeast Senegal. “You feel like you walk into an oven,” she said. Temperatures at Fongoli can reach 110 degrees Fahrenheit or more. During every dry season, brush fires sweep across the parched landscape, leaving behind leafless trees and baked, orange soil. “It’s really nuts,” said Ms. Wessling, now a graduate student at the Max Planck Institute for Evolutionary Anthropology. Yet Ms. Wessling and her colleagues keep coming back to Fongoli, despite the harsh conditions. That’s because it’s home to some remarkable residents: chimpanzees. To study them, scientists have mostly traveled to African rain forests and woodlands, where the apes live in dense groups. The sparse populations of chimpanzees that live on savannas in western and central Africa are far less understood. Ms. Wessling and her colleagues think there are important lessons to be learned from chimps like the ones at Fongoli. Because they are our closest living relatives, they may even tell us something about our own deep history. Millions of years ago, our apelike ancestors gradually moved from woodlands to savannas and began walking upright at some point. The Fongoli chimpanzees demonstrate just how difficult that transition would have been — and how that challenge may have driven some major changes in our evolution, from evolving sweat glands to losing fur and walking upright. The savanna became the subject of long-term research in 2000, when Ms. Wessling’s undergraduate adviser at Iowa State University, Jill D. Pruetz, first paid a visit. Surveying Fongoli, Dr. Pruetz decided it would be a good place to observe the differences between chimpanzee life on a savanna compared to forests. In forests, for example, chimpanzees typically thrive on a diet of ripe fruit. That’s a rare treat on a savanna. © 2018 The New York Times Company

Keyword: Evolution
Link ID: 24920 - Posted: 04.28.2018

Nicola Davis Researchers in the US say they have managed to keep the brains of decapitated pigs alive outside of the body for up to 36 hours by circulating an oxygen-rich fluid through the organs. While the scientists, led by Yale University neuroscientist Nenad Sestan, say the brains are not conscious, they add the feat might help researchers to probe how the brain works, and aid studies into experimental treatments for diseases ranging from cancer to dementia. The revelation, disclosed in the MIT Technology Review and based on comments Sestan made at a meeting at the US National Institutes of Health in March, has received a mixed reaction in the scientific community. A neuroscientist explains: the need for ‘empathetic citizens’ - podcast Anna Devor, a neuroscientist at the University of California, San Diego, told the MIT Technology Review the feat could help researchers probe the connections between brain cells, allowing them to build a “brain atlas”. However others were quick to stress that the development did not mean humans could expect to cheat death any time soon, noting that it is not possible to transplant a brain into a new body. “That animal brain is not aware of anything, I am very confident of that,” Sestan is reported to have told the NIH meeting. But he noted that ethical considerations abound: “Hypothetically, somebody takes this technology, makes it better, and restores someone’s [brain] activity. That is restoring a human being. If that person has memory, I would be freaking out completely.” © 2018 Guardian News and Media Limited

Keyword: Miscellaneous
Link ID: 24919 - Posted: 04.28.2018

by Melissa Healy Sometimes forgotten in the spiraling crisis of opiate abuse is a clinical fact about narcotic pain medications: Addiction is basically an unwanted side effect of drugs that are highly effective at blunting pain. Addiction, of course, is a particularly dangerous and disruptive side effect, since it hijacks a patient’s brain and demands escalating doses of opioid drugs to hold withdrawal symptoms at bay. What if there were a drug that did the job opioids do best — relieve pain — without prompting many of their negative side effects, especially addiction? A researcher from the University of Michigan Medical School may have done just that. Tomas Joaquin Fernandez has described a process for designing opioid-like drugs that would act on pain receptors in the brain while blocking the receptors responsible for fostering dependence and building tolerance. Using pain-relieving peptides released by the brain as models, Fernandez and colleagues developed a library of “peptidomimetics.” These agents were small enough to get into the brain, and they worked on different opioid receptors in different ways. When they tested one such compound in mice, they found that it not only relieved pain, it also induced less buildup of tolerance and less physical dependence than morphine. In other words, it was less addictive. © 1996-2018 The Washington Post

Keyword: Pain & Touch; Drug Abuse
Link ID: 24918 - Posted: 04.28.2018

John Henning Schumann Drew was in his early 30s. His medical history included alcohol abuse, but he had been sober for several months when he became my patient. His previous doctor had given him a prescription for Ativan, or lorazepam, which is frequently used to allay tremors and seizures from alcohol withdrawal. My first inclination was to wean him off the medication by lowering the dose and telling him to take it less frequently. But inertia is strong in medical care, and Drew prevailed upon me to continue providing lorazepam at his regular dose for another month while he solidified his situation with a new job. The next time I heard about him was a couple of weeks later when a colleague read me Drew's obituary in the local paper. There was no cause of death listed. But I knew he could have run into serious trouble if he had mixed alcohol or other drugs with his lorazepam. Lorazepam is a benzodiazepine, a class of medicines known as sedative-hypnotics. They're used frequently in the U.S. to treat anxiety and insomnia. Other drugs in the same category include Valium and Xanax. The problem with benzos, as they're also known, is that they're highly addictive medications, both physically and psychologically. Abruptly stopping them can lead to withdrawal symptoms like the ones Drew hoped to avoid when he kicked alcohol. Moreover, with long-term use, our metabolism adjusts to benzos. We need higher doses to achieve the same effects. © 2018 npr

Keyword: Drug Abuse
Link ID: 24917 - Posted: 04.28.2018

By Diana Kwon Scientists have long attempted to understand where, and how, the brain stores memories. At the beginning of the 20th century, German scientist Richard Semon coined the term “engram” to describe the hypothetical physical representations of memories in the brain. Then, in the 1940s, Canadian psychologist Donald Hebb proposed that, when neurons encoded memories, connections, called synapses, between coactivated memory, or engram, cells were strengthened—a theory that was famously paraphrased as neurons that “fire together, wire together.” These two ideas have become the cornerstone of memory research—and in the decades since they first emerged, scientists have amassed evidence supporting them. “Donald Hebb suggested that it’s not engram cells that are the critical part of storing the memory, it’s the synapse between engram cells,” says Bong-Kiun Kaang, a neuroscientist at Seoul National University in South Korea. However, he adds, while there has been much indirect evidence that such a process underlies memory formation, such as studies showing long-term potentiation (the process through which two simultaneously activated neurons show enhanced connectivity), direct evidence has been lacking. One of the key issues has been the lack of tools to directly observe this process, Kaang says. To overcome this limitation, he and his colleagues injected a virus containing recombinant DNA—coding for different colors of fluorescent proteins for engram and non-engram cells—into the brains of mice. Using this technique, the team was able to pinpoint which type of cell had connected with a postsynaptic neuron. The endeavor wasn’t easy. Developing the method and getting it to work experimentally was a painstaking process that took almost a decade, Kaang tells The Scientist. So when his team finally managed to get promising results around two years ago, “we were very excited,” he says. © 1986-2018 The Scientist

Keyword: Learning & Memory
Link ID: 24916 - Posted: 04.28.2018