Chapter 16. None

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By Anna Azvolinsky Differences in male and female rodent sexual behaviors are programmed during brain development, but how exactly this occurs is not clear. In the preoptic area (POA) of the brain—a region necessary for male sex behavior—the female phenotype results from repression of male-linked genes by DNA methylation, according to a study published today (March 30) in Nature Neuroscience. There is very little known about how the brain is masculinized—and even less about how it is feminized—even though the question has been studied for more than 50 years, said Bridget Nugent, study author and now a postdoctoral fellow at the University of Pennsylvania. These sex differences in the brain are programmed toward the end of fetal development, through to one week after birth in rodents. In males, testicular hormones drive masculinization of the brain; this was thought to occur by direct induction of gene expression by hormone-associated transcription factors. Because a feminized brain occurred in the absence of ovarian hormone signals, most researchers assumed that the female brain and behavior was a sort of default state, programmed during development when no male hormones are present. But the downstream mechanisms of how hormones can modify gene expression were not previously known. “This study reveals that DNA methylation plays an important role in regulating sexual differentiation,” said Nirao Shah, who also studies the neural basis for sex-specific behaviors at the University of California, San Francisco, but was not involved with the work. © 1986-2015 The Scientist

Keyword: Sexual Behavior; Epigenetics
Link ID: 20740 - Posted: 03.31.2015

By Maggie Fox and Jane Derenowski A new strain of the polio-like EV-D68 may be causing the rare and mystifying cases of muscle weakness that's affected more than 100 kids across the United States, researchers reported Monday. They say they've found the strongest evidence yet that the virus caused the polio-like syndrome, but they also say it appears to be rare and might have to do with the genetic makeup of the patients. No other germ appears to be responsible, the team reports in the journal Lancet Infectious Diseases. But because most kids were tested many days after they first got sick, it may be impossible to ever know for sure. The body will have cleared the virus itself by then, said Dr. Charles Chiu of the University of California San Francisco, who helped conduct the study. "This is a virus that causes the common cold," Chiu told NBC News. "Parents don't bring their kids in until they are really sick. By that time, typically, the viral levels may be very, very low or undetectable." "Every single virus that we found in the children corresponded to new strain of the virus, called B-1." Enterovirus D68 (EV-D68) is one of about 100 different enteroviruses that infect people. They include polio but also a range of viruses that cause cold-like symptoms. Polio's the only one that is vaccinated against; before widespread vaccination it crippled 35,000 people a year in the United States.

Keyword: Movement Disorders
Link ID: 20739 - Posted: 03.31.2015

By Lawrence Berger A cognitive scientist and a German philosopher walk into the woods and come upon a tree in bloom: What does each one see? And why does it matter? While that may sound like the set-up to a joke making the rounds at a philosophy conference, I pose it here sincerely, as a way to explore the implications of two distinct strains of thought — that of cognitive science and that of phenomenology, in particular, the thought of Martin Heidegger, who offers a most compelling vision of the ultimate significance of our being here, and what it means to be fully human. When we feel that someone is really listening to us, we feel more alive, we feel our true selves coming to the surface — this is the sense in which worldly presence matters. It can be argued that cognitive scientists tend to ignore the importance of what many consider to be essential features of human existence, preferring to see us as information processors rather than full-blooded human beings immersed in worlds of significance. In general, their intent is to explain human activity and life as we experience it on the basis of physical and physiological processes, the implicit assumption being that this is the domain of what is ultimately real. Since virtually everything that matters to us as human beings can be traced back to life as it is experienced, such thinking is bound to be unsettling. For instance, an article in The Times last year by Michael S. A. Graziano, a professor of psychology and neuroscience at Princeton, about whether we humans are “really conscious,” argued, among other things, that “we don’t actually have inner feelings in the way most of us think we do.” © 2015 The New York Times Company

Keyword: Attention; Consciousness
Link ID: 20738 - Posted: 03.31.2015

By Anne Skomorowsky Because Germanwings pilot Andreas Lubitz killed himself when he purposefully drove a plane carrying 149 other people into a mountain in the Alps, there has been an assumption that he suffered from “depression”—an assumption strengthened by the discovery of antidepressants in his home and reports that he had been treated in psychiatry and neurology clinics. Many patients and other interested parties are rightly concerned that Lubitz’s murderous behavior will further stigmatize the mentally ill. It is certainly true that stigma may lead those in need to avoid treatment. When I was a psychiatrist at an HIV clinic, I was baffled by the shame associated with a visit to see me. Patients at the clinic had advanced AIDS, often contracted through IV drug use or sex work, and many had unprotected sex despite their high viral loads. Some were on parole. Many had lost custody of their children. Many lived in notorious single-room occupancy housing and used cocaine daily. But these issues, somehow, were less embarrassing than the suggestion that they be evaluated by a psychiatrist. Even doctors invoke “depression” to explain anything a reasonable adult wouldn’t do. For my clinic patients, it was shameful to be mentally ill. But to engage in antisocial behavior as a way of life? Not so bad. I think my patients were on to something. Bad behavior—even suicidal behavior—is not the same as depression. It is a truism in psychiatry that depression is underdiagnosed. But as a psychiatrist confronted daily with “problem” patients in the general hospital where I work, I find that depression is also overdiagnosed. Even doctors invoke “depression” to explain anything a reasonable adult wouldn’t do. © 2014 The Slate Group LLC.

Keyword: Depression
Link ID: 20736 - Posted: 03.31.2015

By Emily Underwood Shielded by the skull and packed with fatty tissue, the living brain is perhaps the most difficult organ for scientists to probe. Functional magnetic resonance imaging (fMRI), which noninvasively measures changes in blood flow and oxygen consumption as a proxy for neuronal activation, lags far behind the actual speed of thought. Now, a new technique may provide the fastest yet method of measuring blood flow in the brain, scientists report online today in Nature Methods. The technique, which bounces laser beams off red blood cells, has a resolution of under a millisecond—slightly less time than it takes a neuron to fire—and it has a far higher spatial resolution than fMRI. Even the most powerful fMRI machines, used only on animals, can image only millimeter-wide swaths of tissues including thousands of cells. The new technique, which takes its measurements from sonic waves produced by the beams, can image structures as small as individual blood vessels and cells (see above). Although the technique is not likely to be feasible in humans due to safety concerns, it could provide an important tool to better understand how blood flow and oxygen consumption is related to brain activity. That’s a key question for those relying on cruder and safer tools, such as fMRI, to study the human brain, researchers say. It is also a powerful tool for studying how errant eddies and whorls of blood in blood vessels can sometimes lead to stroke, they say. © 2015 American Association for the Advancement of Science

Keyword: Brain imaging
Link ID: 20735 - Posted: 03.31.2015

|By Dwayne Godwin and Jorge Cham Our minds are veritable memory machines. © 2015 Scientific American

Keyword: Learning & Memory
Link ID: 20734 - Posted: 03.31.2015

By Victoria Gill Science reporter, BBC News Researchers in Denmark have revealed how porpoises finely adjust the beams of sound they use to hunt. The animals hunt with clicks and buzzes - detecting the echoes from their prey. This study showed them switching from a narrow to a wide beam of sound - "like adjusting a flashlight" - as they homed in on a fish. Researchers think that other whales and dolphins may use the same technique to trap a fish in their beam of sound in the final phase of an attack. This could help prevent porpoises, whales and dolphins' prey from evading their capture. By revealing these acoustic secrets in detail, researchers are hoping to develop ways to prevent porpoises, and other toothed whales, from becoming trapped in fishing nets. The study, published in the journal eLife, was led by Danuta Wisniewska of Aarhus University. She and her colleagues worked with harbour porpoises in a semi-natural enclosure on the coast of Denmark. "The facility is quite exceptional, " explained Dr Wisniewska. "The animals still have access to the seafloor and are only separated from the harbour by a net. Fish are able to come in, so they're still hunting." In this unique environment, the researchers were able to fit the porpoises with sound-detecting tags, and to place an array of microphones to pick up sound around their enclosure. The team carried out a series of these experiments to work out where the sound energy the porpoises produced was being directed In one experiment, researchers dropped fish into the water to tempt the porpoises to hunt. As echolocating porpoises, whales and dolphins hunt, they switch from an exploratory clicking to a more intense, high frequency buzz - to elicit a continuous echo from the fish they are pursuing. Their beam can be envisaged a cone of sound, said Dr Wisniewska, comparing it to the cone-shaped beam of light from a torch. © 2015 BBC.

Keyword: Hearing
Link ID: 20731 - Posted: 03.30.2015

Just like the human brain itself, the European Commission’s billion-euro Human Brain Project (HBP) defies easy explanation. Launched 18 months ago, the massive project is complex and, to most observers, confusing. Many people—both scientists and non-scientists—have thus accepted a description of the project that emerged from its leaders and its publicity machine: the aim of simulating the entire human brain in a supercomputer and so find cures for psychiatric and neurological disorders. Like many simplistic explanations of the brain, that characterization of the project provoked a backlash from neuroscientists. This climaxed in a full-scale uprising last summer, when hundreds of researchers signed a critical open letter to the commission (www.neurofuture.eu). Autocratic management, they complained, was running the project off its scientific course and exaggerating its clinical reach. An independent committee was established to investigate and mediate on the dispute. Last week it published its report. This time, the main points were easier for outsiders to decipher. The rebellious neuroscientists who made the complaints were correct. The brain project is failing and must be fixed. The committee’s criticisms endorse more or less all the concerns of the scientists. The project fails not only in its governance, the report says, but also in its scientific plan—particularly the core aim, the simulation of the entire brain that critics had long dismissed as unrealistic. © 2015 Scientific American

Keyword: Brain imaging
Link ID: 20730 - Posted: 03.30.2015

Founded by two men in Akron, Ohio, in 1935, Alcoholics Anonymous has since spread around the world as a leading community-based method of overcoming alcohol dependence and abuse. Many people swear by the 12-step method, which has become the basis of programs to treat the abuse of drugs, gambling, eating disorders and other compulsive behaviors. But not everyone's a fan. In a recent critique of AA, author Gabrielle Glaser writes in the April issue of The Atlantic that, "Nowhere in the field of medicine is treatment less grounded in modern science." Glaser, whose 2013 book, Her Best-Kept Secret, explores what she calls "the epidemic of female drinking" in the U.S., says recent research on the brain suggests that the abstinence advocated by AA isn't the only solution — or even the best for many people. Cognitive therapy combined with the medication naltrexone, Glaser says, can help ease cravings and has been shown in some studies to help some problem drinkers learn to drink moderately without quitting. Glaser's magazine story has drawn fire from defenders of AA, including Huffington Post writer Tommy Rosen, who calls himself "a person in long-term recovery (23 years) who overcame severe drug addiction and alcoholism in great part due to the 12 Steps." Glaser's article, Rosen writes, is "painfully one-sided." Therapist and psychology reporter Robi Ludwig told Glaser and the host of MSNBC's program All in With Chris Hayes last week that she thinks it's "very dangerous to put out the idea that AA doesn't work. Does it work for everybody? No. There's not going to be one form of treatment that works for everybody." © 2015 NPR

Keyword: Drug Abuse
Link ID: 20729 - Posted: 03.28.2015

Patrick Fuller is a neuroscientist at Harvard Medical School's esteemed Division of Sleep Medicine. What have you found in your research on the "neurocircuit basis" that supports sleep? In specific reference to our recent work on the brainstem slow-wave-sleep promoter "center," we showed that this region of the brain is first connected (synaptically) to an important wake-promoting region of the brainstem that in turn is connected with important wake-promoting circuitry of the forebrain, which itself connects to the cerebral cortex. Essentially, we provided a circuit "wiring diagram" by which activation of brainstem sleep-promoting neurons might produce "whole brain" sleep. The reason I emphasize the word "neurocircuit" in our work is because I believe that in order to understand how the brain accomplishes virtually anything, one must first understand the functional cellular and synaptic "scaffolding" from which brain phenomena emerge. Tell me about how circadian regulation affects our sleep and wakeful consciousness. So it all starts (and ends!) with a little biological clock in our brain. The so-called "master" circadian clock is actually a collection of neurons located in a small region of the hypothalamus, itself a very small structure. (In humans, the hypothalamus is about the size of an almond.) This clock is remarkable for many reasons, perhaps most notably that no other region of the brain can assume its function if/when it is damaged. The clock's fundamental role is to keep us "synchronized" with the Earth's light-dark cycle as well as keep our body's internal rhythms synchronized with one another. And we now know that proper external and internal synchronization is fundamental to our physical and mental well-being. ©2015 TheHuffingtonPost.com, Inc.

Keyword: Sleep
Link ID: 20728 - Posted: 03.28.2015

By Nicholas Bakalar Air pollution — even for just one day — significantly increases the risk of stroke, a large review of studies has found. Researchers pooled data from 103 studies involving 6.2 million stroke hospitalizations and deaths in 28 countries. The analysis, published online in BMJ, found that all types of pollution except ozone were associated with increased risk for stroke, and the higher the level of pollution, the more strokes there were. Daily increases in pollution from nitrogen dioxide, sulfur dioxide, carbon monoxide and particulate matter were associated with corresponding increases in strokes and hospital admissions. The strongest associations were apparent on the day of exposure, but increases in particulate matter had longer-lasting effects. The exact reason for the effect is unclear, but studies have shown that air pollution can constrict blood vessels, increase blood pressure and increase the risk for blood clots. Other research has tied air pollution to a higher risk of heart attacks, stroke and other ills. The lead author, Dr. Anoop Shah, a lecturer in cardiology at the University of Edinburgh, said that there was little an individual can do when air pollution spikes. “If you’re elderly, or have co-morbid conditions, you should stay inside,” he said. But policies leading to cleaner air would have the greatest impact, he said. “It’s a question of getting cities and countries to change.” © 2015 The New York Times Company

Keyword: Stroke; Neurotoxins
Link ID: 20727 - Posted: 03.28.2015

Jon Hamilton A biotech company and two scientists hope to change that. On Wednesday, Avalanche Biotechnologies in Menlo Park and the University of Washington in Seattle announced a licensing agreement to develop the first treatment for colorblindness. The deal brings together a gene therapy technique developed by Avalanche with the expertise of vision researchers at the University of Washington. "Our goal is to be treating colorblindness in clinical trials in patients in the next one to two years," says Thomas Chalberg, the founder and CEO of Avalanche. Dalton the squirrel monkey during the color vision test. i Dalton the squirrel monkey during the color vision test. Courtesy of Neitz Laboratory The agreement has its roots in a scientific breakthrough that occurred six years ago. That's when two vision researchers at the University of Washington used gene therapy to cure a common form of colorblindness in squirrel monkeys. "This opened the possibility of ultimately getting this to cure colorblindness in humans," says Jay Neitz, who runs the Color Vision Lab at UW along with his wife, Maureen Neitz. The couple knew that transferring their success from monkey to man would be a challenge. But they were determined, says Maureen Neitz. "We've spent our entire careers writing NIH grants where we say our goal is to improve human health." © 2015 NPR

Keyword: Vision
Link ID: 20725 - Posted: 03.26.2015

By BONNIE ROCHMAN Reasons Why I Shouldn’t Have to Go Tonight: If I wanted to talk about it, I would. / It’s my body. / It’s a waste of time. / It’s a waste of money. / I know what I need to know. / It sounds pretty stupid to me. PLEASE DON’T MAKE ME GO. I DON’T WANT TO GO. The plea came from Leah Likin, a fifth grader. It was addressed to her mother, who had registered both of them for a two-part course on puberty called “For Girls Only.” The missive, which included additional objections, failed: Mother took daughter anyway. But Leah had plenty of company, peers who shared her resistance, their arms crossed, their eyes downcast. Last year, the course, which is split into sessions for preteen boys and girls and held mostly in and around Seattle, and also in the Bay Area, pulled in 14,000 attendees. They heard about it from their pediatricians, or through word of mouth. The creator of the course, Julie Metzger, has been trying for nearly three decades to turn what’s so often at best a blush-inducing experience — the “facts of life” talk — into a candid dialogue between parents and children. In the mid-1980s, she was a graduate student at the University of Washington School of Nursing when she reviewed survey data on how women had learned about menarche, or the onset of menstruation, for her master’s thesis. Most reported getting information from gym class or their mothers. “You can picture those conversations lasting from 10 seconds to 10 hours,” Metzger says. “And I thought, Wouldn’t it be interesting if you actually had a class where you sit with your parents and hear these things from someone? What if that class were fun and funny and interactive?” Metzger, who is 56 and vigorous, with flushed cheeks and blue eyes, says she has always been comfortable talking about sexuality; her father was a urologist, her mother a nurse. “Hand me a microphone,” she says. “I get so into this topic that I can make myself cry in front of the class, and it’s real.” © 2015 The New York Times Company

Keyword: Sexual Behavior
Link ID: 20722 - Posted: 03.26.2015

Jon Hamilton Doctors are much more likely to level with patients who have cancer than patients who have Alzheimer's, according to a report released this week by the Alzheimer's Association. The report found that just 45 percent of Medicare patients who'd been diagnosed with Alzheimer's said they were informed of the diagnosis by their doctor. By contrast, more than 90 percent of Medicare patients with cancer said they were told by their doctor. "What we found is really shocking," says Beth Kallmyer, vice president of constituent services for the Alzheimer's Association. "This is reminiscent of what happened in the 1960s and 1970s with cancer," she says. "But that's changed now, and it really needs to change for Alzheimer's as well." For years, the association's help line has been receiving complaints from family members who say that doctors are reluctant to reveal an Alzheimer's diagnosis, Kallmyer says. So the association decided to investigate by studying medical records and survey results from Medicare recipients. To make sure that Alzheimer's patients hadn't simply forgotten what a doctor said, the group also looked at Medicare survey responses from family members and other caregivers. The result wasn't much better: Just 53 percent said a doctor told them of the patient's diagnosis. © 2015 NPR

Keyword: Alzheimers
Link ID: 20721 - Posted: 03.25.2015

By Rachel Feltman I'm not usually one for heartstring-tugging ads, but this collaboration between Valspar Paint and EnChroma, a company that makes color-boosting sunglasses for the color-blind, is pretty cool. And the coolest thing about the glasses in the above video is that they weren't designed to help the color-blind at all. Smithsonian Magazine reports that EnChroma Labs founder Don McPherson (a materials scientist) had originally engineered the glasses with surgeons in mind. The lenses contained rare earth iron and absorbed a ton of light to protect surgeons performing laser eye surgery. The boosted absorption also made colors pop more vibrantly, allowing them to more easily distinguish among different tissues during surgery. But the stellar eye protection and vibrant colors meant that many surgeons wanted to wear them outside the operating room. McPherson himself started using them as regular sunglasses. And when a color-blind friend tried them on, he was amazed: He could distinguish orange traffic cones from the grass and pavement around them. He was perceiving color in a way he never had before. Now EnChroma sells the glasses (which have been specifically tailored for color blindness since the accidental discovery) for a few hundred bucks a pop. McPherson explains that all people have three photopigments in the eye, also known as cones, which are sensitive to blue, green and red. Blue operates fairly independently, while the red and green cones, in most humans, overlap, affecting the perception of certain colors. For example, if 10 photons landed on the red cone and 100 landed on the green cone, the object viewed would appear more green. Whereas if an equal number of photons landed on the red and green cones, the color perceived would be yellow.

Keyword: Vision
Link ID: 20720 - Posted: 03.25.2015

Alice Park We start to talk before we can read, so hearing words, and getting familiar with their sounds, is obviously a critical part of learning a language. But in order to read, and especially in order to read quickly, our brains have to “see” words as well. At least that’s what Maximilian Riesenhuber, a neuroscientist at Georgetown University Medical Center, and his colleagues found in an intriguing brain-mapping study published in the Journal of Neuroscience. The scientists recruited a small group of college students to learn a set of 150 nonsense words, and they imaged their brains before and after the training. Before they learned the words, their brains registered them as a jumble of symbols. But after they were trained to give them a meaning, the words looked more like familiar words they used every day, like car, cat or apple. The difference in way the brain treated the words involved “seeing” them rather than sounding them out. The closest analogy would be for adults learning a foreign language based on a completely different alphabet system. Students would have to first learn the new alphabet, assigning sounds to each symbol, and in order to read, they would have to sound out each letter to put words together. In a person’s native language, such reading occurs in an entirely different way.

Keyword: Language
Link ID: 20719 - Posted: 03.25.2015

By Harriet Brown If you’re one of the 45 million Americans who plan to go on a diet this year, I’ve got one word of advice for you: Don’t. You’ll likely lose weight in the short term, but your chance of keeping if off for five years or more is about the same as your chance of surviving metastatic lung cancer: 5 percent. And when you do gain back the weight, everyone will blame you. Including you. This isn’t breaking news; doctors know the holy trinity of obesity treatments—diet, exercise, and medication—don’t work. They know yo-yo dieting is linked to heart disease, insulin resistance, higher blood pressure, inflammation, and, ironically, long-term weight gain. Still, they push the same ineffective treatments, insisting they’ll make you not just thinner but healthier. In reality, 97 percent of dieters regain everything they lost and then some within three years. Obesity research fails to reflect this truth because it rarely follows people for more than 18 months. This makes most weight-loss studies disingenuous at best and downright deceptive at worst. One of the principles driving the $61 billion weight-loss industries is the notion that fat is inherently unhealthy and that it’s better, health-wise, to be thin, no matter what you have to do to get there. But a growing body of research is beginning to question this paradigm. Does obesity cause ill health, result from it, both, or neither? Does weight loss lead to a longer, healthier life for most people? Studies from the Centers for Disease Control and Prevention repeatedly find the lowest mortality rates among people whose body mass index puts them in the “overweight” and “mildly obese” categories.

Keyword: Obesity
Link ID: 20718 - Posted: 03.25.2015

By Kate Baggaley Mutations on a gene necessary for keeping cells clean can cause Lou Gehrig’s disease, scientists report online March 24 in Nature Neuroscience. The gene is one of many that have been connected to the condition. In amyotrophic lateral sclerosis, also known as Lou Gehrig’s disease, nerve cells that control voluntary movement die, leading to paralysis. Scientists have previously identified mutations in 29 genes that are linked with ALS, but these genes account for less than one-third of all cases. To track down more genes, a team of European researchers looked at the protein-coding DNA of 252 ALS patients with a family history of the disease, as well as of 827 healthy people. The team discovered eight mutations on a gene called TBK1 that were associated with ALS. TBK1 normally codes for a protein that controls inflammation and cleans out damaged proteins from cells. “We do not know which of these two principle functions of TBK1 is the more relevant one” to ALS, says coauthor Jochen Weishaupt, a neurologist at Ulm University in Germany. In cells with one of the eight TBK1 mutations, the protein either is missing or lacks components that it needs to interact with other proteins, the researchers found. TBK1 mutations may explain 2 percent of ALS cases that run in families, which make up about 10 percent of all incidences of the disease, Weishaupt says. © Society for Science & the Public 2000 - 2015

Keyword: ALS-Lou Gehrig's Disease ; Genes & Behavior
Link ID: 20716 - Posted: 03.25.2015

By NICHOLAS BAKALAR Concussions are not as common in Major League Baseball as they are in professional football, but they happen often enough, with players getting hit by pitches, running into walls or catching a knee in the head sliding into a base. Catchers are particularly at risk — a foul tip off the mask will snap the neck back and give the brain a solid rattle. Collisions at the plate take a toll, too. Now, a study published in the American Journal of Sports Medicine suggests that position players in the majors who sustain concussions do not hit as effectively in their first weeks back after their injury. Under Major League Baseball rules, players can return after a concussion if they pass the concussion protocol — a series of interviews and tests of physical and mental functioning. But the new study found that even after passing the tests and having no apparent symptoms, hitters showed an initial decline when they returned to action. The study identified 66 position players who had concussions between 2007 and 2013, including some who never went on the disabled list. The study then compared their performance in the weeks before and after the injury. The gap was noticeable. In the two weeks before their injuries, the players hit .249 with a .315 on base percentage and a .393 slugging average. For the two weeks after the injury, their line was .227/.287/.347. Baseball instituted a seven-day disabled list in 2011, specifically to let players recover from concussions while allowing the team to maintain a full roster. But there is no set time that a player must stay out after a concussion. If he passes the protocol, he is cleared to play. © 2015 The New York Times Company

Keyword: Brain Injury/Concussion
Link ID: 20715 - Posted: 03.24.2015

By Brian Handwerk In the U.S., legal hurdles have long hampered research into marijuana. But as more states approve medical and even recreational marijuana, scientific inquiries have spiked, especially studies aimed at finding out what exactly is in today's weed—and what it does to our bodies. In Colorado, which made marijuana legal in November 2012, the latest results show that the pot lining store shelves is much more potent than the weed of 30 years ago. But the boost in power comes at a cost—modern marijuana mostly lacks the components touted as beneficial by medical marijuana advocates, and it is often contaminated with fungi, pesticides and heavy metals. “There's a stereotype, a hippy kind of mentality, that leads people to assume that growers are using natural cultivation methods and growing organically," says Andy LaFrate, founder of Charas Scientific, one of eight Colorado labs certified to test cannabis. "That's not necessarily the case at all." LaFrate presented his results this week at a meeting of the American Chemical Society (ACS) in Denver. LaFrate says he's been surprised at just how strong most of today's marijuana has become. His group has tested more than 600 strains of marijuana from dozens of producers. Potency tests, the only ones Colorado currently requires, looked at tetrahydrocannabinol (THC), the psychoactive compound that produces the plant's famous high. They found that modern weed contains THC levels of 18 to 30 percent—double to triple the levels that were common in buds from the 1980s. That's because growers have cross-bred plants over the years to create more powerful strains, which today tout colorful names like Bruce Banner, Skunkberry and Blue Cookies.

Keyword: Drug Abuse
Link ID: 20712 - Posted: 03.24.2015