When Jack O'Connor was 19, he was so desperate to beat his addictions to alcohol and opioids that he took a really rash step. He joined the Marines. "This will fix me," O'Connor thought as he went to boot camp. "It better fix me or I'm screwed." After 13 weeks of sobriety and exercise and discipline, O'Connor completed basic training, but he started using again immediately. "Same thing," he says. "Percocet, like, off the street. Pills." Percocet is the brand name for acetaminophen and oxycodone. Oxycodone is a powerful opioid. It's one of the most commonly prescribed painkillers, and is a key factor in one of the country's most pressing public health problems — an opioid addiction epidemic. It is a crisis that started, in part, from the over-prescription of painkillers, like Percocet, and then shifted to heroin, as people addicted to prescription drugs looked for a cheaper high. O'Connor is one of an estimated 2.5 million Americans addicted to opioids and heroin, according to the National Institute on Drug Abuse. Over three years, he detoxed from prescription painkillers — and heroin — more than 20 times. Each time, he started using again. So why is it so hard for opioid addicts to quit? You can boil it down to two crucial bits of science: the powerful nature of opioids and the neuroscience behind how addiction hijacks the brain. "The first recording of opioid use was 5,000 years ago," says Dr. Seddon Savage, an addiction and pain specialist at Dartmouth College. It was "a picture of the opium poppy and the words 'the joy plant.' "

Keyword: Drug Abuse
Link ID: 21773 - Posted: 01.11.2016

Don’t blame impulsive people for their poor decisions. It’s not necessarily their fault. Impulsivity could result from not having enough time to veto our own actions. At least that is the implication of a twist on a classic experiment on free will. In 1983, neuroscientist Benjamin Libet performed an experiment to test whether we have free will. Participants were asked to voluntarily flex a finger while watching a clock-face with a rotating dot. They had to note the position of the dot as soon as they became aware of their intention to act. As they were doing so, Libet recorded their brain activity via EEG electrodes attached to the scalp. He found that a spike in brain activity called the readiness potential, which precedes a voluntary action, occurred about 350-milliseconds before the volunteers became consciously aware of their intention to act. The readiness potential is thought to signal the brain preparing for movement. Libet interpreted his results to mean that free will is an illusion. But we’re not complete slaves to our neurons, he reasoned, as there was a 200-millisecond gap between conscious awareness of our intention and the initiation of movement. Libet argued that this was enough time to consciously veto the action, or exert our “free won’t”. While Libet’s interpretations have remained controversial, this hasn’t stopped scientists carrying out variations of his experiment. Among other things, this has revealed that people with Tourette’s syndrome, who have uncontrollable tics, experience a shorter veto window than people without the condition, as do those with schizophrenia. © Copyright Reed Business Information Ltd.

Keyword: Consciousness; ADHD
Link ID: 21772 - Posted: 01.11.2016

By Veronique Greenwood Last year a new sleep drug called Belsomra came on the market, featuring a mechanism unlike any other pill: it mimics narcolepsy. That might sound odd, but the potential users are many. More than 8.5 million Americans take prescription sleep aids, and many others use snooze-inducing over-the-counter medications. All these pills, including Belsomra, do one of two things: they enhance the effects of the neurotransmitter GABA, known for quieting brain activity, or they arrest the actions of neurotransmitters that keep the brain aroused. Yet it's not quite as simple as flipping a switch; the drugs have a range of side effects, including daytime drowsiness, hallucinations and sleep-eating. Here's an overview of the sleeping pills currently available in the U.S.—plus a look at cognitive-behavior therapy for insomnia, which may be more successful than drugs alone. It requires a lot more work than popping a pill, but cognitive-behavior therapy for insomnia (CBT-I) has been shown to successfully alleviate sleep problems. Aimed at developing healthy habits, CBT-I comes with a lot of homework—between weekly or so visits with a specialist, a patient keeps track of hours spent in bed and hours sleeping and uses the bed only for sleep and sex. The patient must stay up until an established bedtime and get up on awakening, generating a sleep deficit that makes it easier to fall asleep at the right time. Avoiding caffeine and alcohol after 4 P.M. and timing exercise so that it doesn't interfere with drowsiness are also part of the system. © 2016 Scientific American

Keyword: Sleep
Link ID: 21770 - Posted: 01.11.2016

by Laura Sanders Young babies get a bad rap. They’re helpless, fickle and noisy. And even though they allegedly sleep for 16 hours a day, those hours come in 20-minute increments. Yet hidden in the chaos of a young infant’s life are some truly magnificent skills — perceptual feats that put adults to shame. So next time your baby loses it because she can’t get her thumb into her mouth, keep in mind that her strengths lie elsewhere. Six-month-old babies can spot subtle differences between two monkey faces easy as pie. But 9-month-olds — and adults — are blind to the differences. In a 2002 study of facial recognition, scientists pitted 30 6-month-old babies against 30 9-month-olds and 11 adults. First, the groups got familiar with a series of monkey and human faces that flashed on a screen. Then new faces showed up, interspersed with already familiar faces. The idea is that the babies would spend more time looking at new faces than ones they had already seen. When viewing human faces, all of the observers, babies and adults alike, did indeed spend more time looking at the new people, showing that they could easily pick out familiar human faces. But when it came to recognizing monkey faces, the youngsters blew the competition out of the water. Six-month-old babies recognized familiar monkey faces and stared at the newcomers longer. But both adults and 9-month-old babies were flummoxed, and looked at the new and familiar monkey faces for about the same amount of time. © Society for Science & the Public 2000 - 2015

Keyword: Development of the Brain; Vision
Link ID: 21769 - Posted: 01.09.2016

By Christof Koch While “size does not matter” is a universally preached dictum among the politically correct, everyday experience tells us that this can't be the whole story—under many conditions, it clearly does. Consider the size of Woody Allen's second favorite organ, the brain. Adjectives such as “highbrow” and “lowbrow” have their origin in the belief, much expounded by 19th-century phrenologists, of a close correspondence between a high forehead—that is, a big brain—and intelligence. Is this true? Does a bigger brain make you necessarily smarter or wiser? And is there any simple connection between the size of a nervous system, however measured, and the mental powers of the owner of this nervous system? While the answer to the former question is a conditional “yes, somewhat,” the lack of any accepted answer to the second one reveals our ignorance of how intelligent behavior comes about. The human brain continues to grow until it reaches its peak size in the third to fourth decade of life. An MRI study of 46 adults of mainly European descent found that the average male had a brain volume of 1,274 cubic centimeters (cm3) and that the average female brain measured 1,131 cm3. Given that a quart of milk equals 946 cm3, you could pour a bit more than that into a skull without any of it spilling out. Of course, there is considerable variability in brain volume, ranging from 1,053 to 1,499 cm3 in men and between 975 and 1,398 cm3 in women. As the density of brain matter is just a little bit above that of water plus some salts, the average male brain weighs about 1,325 grams, close to the proverbial three pounds often cited in U.S. texts. © 2016 Scientific American

Keyword: Intelligence; Evolution
Link ID: 21768 - Posted: 01.09.2016

Pete Etchells Autonomous Sensory Meridian Response, or ASMR, is a curious phenomenon. Those who experience it often characterise it as a tingling sensation in the back of the head or neck, or another part of the body, in response to some sort of sensory stimulus. That stimulus could be anything, but over the past few years, a subculture has developed around YouTube videos, and their growing popularity was the focus of a video posted on the Guardian this last week. It’s well worth a watch, but I couldn’t help but feel it would have been a bit more interesting if there had been some scientific background in it. The trouble is, there isn’t actually much research on ASMR out there. To date, only one research paper has been published on the phenomenon. In March last year, Emma Barratt, a graduate student at Swansea University, and Dr Nick Davis, then a lecturer at the same institution, published the results of a survey of some 500 ASMR enthusiasts. “ASMR is interesting to me as a psychologist because it’s a bit ‘weird’” says Davis, now at Manchester Metropolitan University. “The sensations people describe are quite hard to describe, and that’s odd because people are usually quite good at describing bodily sensation. So we wanted to know if everybody’s ASMR experience is the same, and of people tend to be triggered by the same sorts of things.” The study asked a range of questions about where, when and why people watch ASMR videos, whether there was any consistency in ASMR-triggering content, as well as whether individuals felt it had any effect on their mood. There was a remarkable consistency across participants in terms of triggering content – whispering worked for the majority of people, followed by videos involving some sort of personal attention, crisp sounds, and slow movements. For the most part, participants reported that they watched ASMR videos for relaxation purposes, or to help them sleep or deal with stress. © 2016 Guardian News and Media Limited

Keyword: Pain & Touch
Link ID: 21767 - Posted: 01.09.2016

AUDIE CORNISH, HOST: It's unusual for an NFL player - a current player - to criticize the league, especially its handling of controversial issues like concussions or domestic violence, but author Johnny Anonymous has done just that. He's an offensive lineman who's written a book under that pseudonym. It's called "NFL Confidential." In it, he details his 2014 season, including training camp and his big break after a starting player gets injured. He's worried about being fired, so we've masked his voice. First, Johnny Anonymous says getting hurt is always on the mind of the player. ANONYMOUS: It's absolutely constant. The NFL's the only league, the only job you'll find in the world where we have a 100 percent injury rate. CORNISH: So walk us through the questions that come to mind for a player when they first hear that, you know, sickening sound and they're lying there on the field. What are you thinking? ANONYMOUS: For some guys, it's fear, which is why you'll see them kicking and screaming and crying, and some guys it's shock. I know for most of us - and probably all of us - the first thing you think is, I'm done; that's it. You think the injury's going to take the game away from you. CORNISH: So in a way, you know, this is how it happens, right, this discussion of, like, why do people take all the painkillers, you know, like, why do people defy doctors? ANONYMOUS: You have to. It's the only way you make it through. I can tell you right now, honestly, that if I am playing a game, I cannot complete that game without painkillers. I will not be an effective player. © 2016 npr

Keyword: Brain Injury/Concussion
Link ID: 21766 - Posted: 01.09.2016

By Josh Izaac Helmets can reduce the risk of traumatic brain injury by almost 20%. But what if we take so many risks when wearing them that we lose the protective edge they provide? This could be the case, according to a study published this week. Researchers observed 80 cyclists under the guise of an “eye-tracking experiment,” pretending to track their eye-motion via a head-mounted camera as the participants inflated a virtual balloon. For some of the participants, the “eye-tracking devices” were mounted on helmets, while others just wore baseball caps, as can be seen in the picture of the equipment above. The further they inflated the balloon without it popping, the higher their reward and their risk-taking score. Participants wearing helmets inflated their balloons on average 30% more than those who wore caps, the team reports in Psychological Science. The finding could affect how we approach safety design and training, the authors say, as increased risk-taking behavior when using safety equipment might counteract the perceived benefit of the equipment. But what causes this effect in the first place? The underlying mechanism might be related to the concept of “social priming,” where people’s actions towards others are altered subconsciously due to exposure to particular words, cues, objects, or symbols. Importantly, this is the first time social priming has been shown to change people’s behaviour even when they are not interacting with others, providing potential new insights into human behavior. So, next time you’re out riding with a helmet, think twice before attempting that wheelie. © 2016 American Association for the Advancement of Science

Keyword: Brain Injury/Concussion
Link ID: 21765 - Posted: 01.09.2016

By Emily Underwood As long as she can remember, 53-year-old Rosa Sundquist has tallied the number of days per month when her head explodes with pain. The migraines started in childhood and have gotten worse as she’s grown older. Since 2008, they have incapacitated her at least 15 days per month, year-round. Head-splitting pain isn’t the worst of Sundquist’s symptoms. Nausea, vomiting, and an intense sensitivity to light, sound, and smell make it impossible for her to work—she used to be an office manager—or often even to leave her light-proofed home in Dumfries, Virginia. On the rare occasions when she does go out to dinner or a movie with her husband and two college-aged children, she wears sunglasses and noise-canceling headphones. A short trip to the grocery store can turn into a full-blown attack “on a dime,” she says. Every 10 weeks, Sundquist gets 32 bee sting–like injections of the nerve-numbing botulism toxin into her face and neck. She also visits a neurologist in Philadelphia, Pennsylvania, who gives her a continuous intravenous infusion of the anesthetic lidocaine over 7 days. The lidocaine makes Sundquist hallucinate, but it can reduce her attacks, she says—she recently counted 20 migraine days per month instead of 30. Sundquist can also sometimes ward off an attack with triptans, the only drugs specifically designed to interrupt migraines after they start. Millions of others similarly dread the onset of a migraine, although many are not afflicted as severely as Sundquist. Worldwide, migraines strike roughly 12% of people at least once per year, with women roughly three times as likely as men to have an attack. © 2016 American Association for the Advancement of Science.

Keyword: Pain & Touch; Neuroimmunology
Link ID: 21764 - Posted: 01.08.2016

By Erin Blakemore Despite all that neurotic clucking and scratching, domestic chickens are pretty unflappable. After all, we’ve bred them to be that way, preferring chill chicks to freaked-out fowl. But the behaviors of more anxious chickens could do more than ruffle a bunch of feathers: New research suggests that studying the genome of flustered birds could shed light on human mental disorders. In a new study published in the journal Genetics, evolutionary biologist Dominic Wright and his team looked at whether there’s a genetic connection between anxious behavior in chickens, mice and humans. Despite the compact size of the chicken genome — it’s just a third of the size of a human’s — the birds’ genes share surprising similarity to those of people. There's another reason why chickens are so great for genetic research. Because there are both wild and domesticated chickens, researchers can observe their contrasting behaviors and easily pin them to genetic differences. Wright bred wild red junglefowl chickens with their calmer cousins, white leghorn chickens, for the experiment. After eight generations, his team was able to run open field tests — experiments during which the birds were put in a brightly-lit arena and assessed for how much time they spent cowering on the periphery instead of strutting through the room. These behavioral tests helped the team identify brave and anxious birds, then narrow down areas of the genome related to variations in anxiety. They identified 10 candidate genes in the hypothalamus, an area of the brain which helps regulate anxiety.

Keyword: Schizophrenia; Emotions
Link ID: 21763 - Posted: 01.08.2016

Blocking the production of new immune cells in the brain could reduce memory problems seen in Alzheimer's disease, a study suggests. University of Southampton researchers said their findings added weight to evidence that inflammation in the brain is what drives the disease. A drug used to block the production of these microglia cells in the brains of mice had a positive effect. Experts said the results were exciting and could lead to new treatments. Up until now, most drugs used to treat dementia have targeted amyloid plaques in the brain which are a characteristic of people with the Alzheimer's disease. But this latest study, published in the journal Brain, suggests that in fact targeting inflammation in the brain, caused by a build-up of immune cells called microglia, could halt progression of the disease. Researchers found increased numbers of microglia in the post-mortem brains of people with Alzheimer's disease. Previous studies have also suggested that these cells could play an important role. Dr Diego Gomez-Nicola, lead study author from the university, said: "These findings are as close to evidence as we can get to show that this particular pathway is active in the development of Alzheimer's disease. "The next step is to work closely with our partners in industry to find a safe and suitable drug that can be tested to see if it works in humans." © 2016 BBC

Keyword: Alzheimers; Glia
Link ID: 21762 - Posted: 01.08.2016

Bruce Bower Youngsters befuddled by printed squiggles on the pages of a storybook nonetheless understand that a written word, unlike a drawing, stands for a specific spoken word, say psychologist Rebecca Treiman of Washington University in St. Louis and her colleagues. Children as young as 3 can be tested for a budding understanding of writing’s symbolic meaning, the researchers conclude January 6 in Child Development. “Our results show that young children have surprisingly advanced knowledge about the fundamental properties of writing,” Treiman says. “This knowledge isn’t explicitly taught to children but probably gained through early exposure to print from sources such as books and computers.” Researchers and theorists have previously proposed that children who cannot yet read don’t realize that a written word corresponds to a particular spoken word. Studies have found, for instance, that nonliterate 3- to 5-year-olds often assign different meanings to the same word, such as girl, depending on whether that word appears under a picture of a girl or a cup. Treiman’s investigation “is the first to show that kids as young as 3 have the insight that print stands for something beyond what’s scripted on the page,” says psychologist Kathy Hirsh-Pasek of Temple University in Philadelphia. Preschoolers who are regularly read to have an advantage in learning that written words have specific meanings, suspects psychologist Roberta Golinkoff of the University of Delaware in Newark. © Society for Science & the Public 2000 - 2015.

Keyword: Language; Dyslexia
Link ID: 21761 - Posted: 01.08.2016

By Darryl Fears Flushed down toilets, poured down sinks and excreted in urine, a chemical component in the pill wafts into sewage systems and ends up in various waterways where it collects in fairly heavy doses. That's where fish soak it up. A recent survey by the U.S. Geological Survey found that fish exposed to a synthetic hormone called 17a-ethinylestradiol, or EE2, produced offspring that struggled to fertilize eggs. The grandchildren of the originally exposed fish suffered a 30 percent decrease in their fertilization rate. The authors mulled the impact of what they discovered and decided it wasn't good. "If those trends continued, the potential for declines in overall population numbers might be expected in future generations," said Ramji Bhandari, a University of Missouri assistant research professor and a visiting scientist at USGS. "These adverse outcomes, if shown in natural populations, could have negative impacts on fish inhabiting contaminated aquatic environments." The study, with Bhandari as lead author, also determined that the chemical BPA, used widely in plastics, had a similar effect on the small Japanese medaka fish used for the research. The medaka was chosen because it reproduces quickly so that scientists can see results of subsequent generations faster than slow reproducing species such as smallmouth bass.

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 21760 - Posted: 01.08.2016

By Emily Underwood Lumos Labs, the company that produces the popular “brain-training” program Lumosity, yesterday agreed to pay a $2 million settlement to the Federal Trade Commission (FTC) for running deceptive advertisements. Lumos had claimed that its online games can help users perform better at work and in school and stave off cognitive deficits associated with serious diseases such as Alzheimer’s, traumatic brain injury, and post-traumatic stress. The $2 million settlement will be used to compensate Lumosity consumers who were misled by false advertising, says Michelle Rusk, a spokesperson with FTC in Washington, D.C. The company will also be required to provide an easy way to cancel autorenewal billing for the service, which includes online and mobile app subscriptions, with payments ranging from $14.95 monthly to lifetime memberships for $299.95. Before consumers can access the games, a pop-up screen will alert them to FTC’s order and allow them to avoid future billing, Rusk says. The action is part of a larger crackdown on companies selling products that purportedly enhance memory or provide some other cognitive benefit, Rusk says. For some time now, FTC has been “concerned about some of the claims we’re seeing out there,” particularly those from companies like Lumos that suggest their games can reduce the effects of conditions such as dementia, she says. After evaluating the literature on Lumos's products, and the broader research on the benefits of brain-training games, “our assessment was they didn’t have adequate science for the claims that they’re making,” she says. © 2016 American Association for the Advancement of Science

Keyword: Learning & Memory; Intelligence
Link ID: 21759 - Posted: 01.07.2016

By Stephani Sutherland A technique called optogenetics has transformed neuroscience during the past 10 years by allowing researchers to turn specific neurons on and off in experimental animals. By flipping these neural switches, it has provided clues about which brain pathways are involved in diseases like depression and obsessive-compulsive disorder. “Optogenetics is not just a flash in the pan,” says neuroscientist Robert Gereau of Washington University in Saint Louis. “It allows us to do experiments that were not doable before. This is a true game changer like few other techniques in science.” Since the first papers were published on optogenetics in the mid-aughts some researchers have mused about one day using optogenetics in patients, imagining the possibility of an off-switch for depression, for instance. The technique, however, would require that a patient submit to a set of highly invasive medical procedures: genetic engineering of neurons to insert molecular switches to activate or switch off cells, along with threading of an optical fiber into the brain to flip those switches. Spurred on by a set of technical advances, optogenetics pioneer Karl Deisseroth, together with other Stanford University researchers, has formed a company to pursue optogenetics trials in patients within the next several years—one of several start-ups that are now contemplating clinical trials of the technique. Circuit Therapeutics, founded in 2010, is moving forward with specific plans to treat neurological diseases. (It also partners with pharmaceutical companies to help them use optogenetics in animal research to develop novel drug targets for human diseases.) © 2016 Scientific America

Keyword: Pain & Touch
Link ID: 21758 - Posted: 01.07.2016

By Anahad O'Connor David Ludwig often uses an analogy when he talks about weight loss: Human beings are not toaster ovens. If we were, then the types of calories we consumed would not matter, and calorie counting would be the most effective way to lose weight. Dr. Ludwig, an obesity expert and professor of nutrition at the Harvard T.H. Chan School of Public Health, argues that weight gain begins when people eat the wrong types of food, which throws their hormones out of whack and sets off a cycle of cravings, hunger and bingeing. In his new book, “Always Hungry?,” he argues that the primary driver of obesity today is not an excess of calories per se, but an excess of high glycemic foods like sugar, refined grains and other processed carbohydrates. Recently, we caught up with Dr. Ludwig to talk about which foods act as “fertilizer for fat cells,” why he thinks the conventional wisdom on weight loss is all wrong, and long-term strategies for weight loss. Here are edited excerpts from our conversation. What is the basic message of your book? The basic premise is that overeating doesn’t make you fat. The process of getting fat makes you overeat. It may sound radical, but there’s literally a century of science to support this point. Simply cutting back on calories as we’ve been told actually makes the situation worse. When we cut back on calories, our body responds by increasing hunger and slowing metabolism. It responds in an effort to save calories. And that makes weight loss progressively more and more difficult on a standard low calorie diet. It creates a battle between mind and metabolism that we’re doomed to lose. But we’ve all been told that obesity is caused by eating too much. Is that not the case? We think of obesity as a state of excess, but it’s really more akin to a state of starvation. If the fat cells are storing too many calories, the brain doesn’t have access to enough to make sure that metabolism runs properly. So the brain makes us hungry in an attempt to solve that problem, and we overeat and feel better temporarily. © 2016 The New York Times Company

Keyword: Obesity
Link ID: 21757 - Posted: 01.07.2016

Katherine Hobson Pregnant women worry about all kinds of things. Can I drink alcohol? (No.) Can I take antidepressants? (Maybe.) Can I do the downward dog? (Yes.) Now there's one less thing to fret about: harm to the baby when the mother takes birth control pill right before conceiving, or during the first few months of pregnancy. According to a study covering more than 880,000 births in Denmark, the overall rate of birth defects was consistent for women who had never taken the pill at all, for those who had used it before getting pregnant and for those who continued on the pill in early pregnancy. (There were about 25 birth defects per 1,000 births for all groups.) The study is important because so many women take the pill – about 16 percent of women of childbearing age in the U.S. When used perfectly, the failure rate of the pill is less than 1 percent, but that jumps to 9 percent under typical use because of missed pills, drug interactions or illness. That means a lot of embryos are exposed to the hormones used in the pill, which can linger for a few months after a woman stops taking it. "Our findings are really reassuring," says Brittany Charlton, an author of the study and a researcher in the Harvard T.H. Chan School of Public Health's epidemiology department. The results also confirm most of the previous research, which has pointed to no overall increase in major birth defects, she says. This study, published in the medical journal BMJ, used national birth, patient and prescription registry data to track contraceptive prescriptions among women who gave birth, then looked at whether birth defects were associated with pill use. © 2016 npr

Keyword: Development of the Brain; Sexual Behavior
Link ID: 21756 - Posted: 01.07.2016

Children conceived via infertility treatments are no more likely to have a developmental delay than children conceived without such treatments, according to a study by researchers at the National Institutes of Health, the New York State Department of Health and other institutions. The findings, published online in JAMA Pediatrics, may help to allay longstanding concerns that conception after infertility treatment could affect the embryo at a sensitive stage and result in lifelong disability. The authors found no differences in developmental assessment scores of more than 1,800 children born to women who became pregnant after receiving infertility treatment and those of more than 4,000 children born to women who did not undergo such treatment. “When we began our study, there was little research on the potential effects of conception via fertility treatments on U.S. children,” said Edwina Yeung, Ph.D., an investigator in the Division of Intramural Population Health Research at NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). “Our results provide reassurance to the thousands of couples who have relied on these treatments to establish their families.” Also taking part in the study were researchers from the University at Albany, New York; the New York State Department of Health, also in Albany; and CapitalCare Pediatrics in Troy, New York. The Upstate KIDS study enrolled infants born to women in New York State (except for New York City) from 2008 to 2010. Parents of infants whose birth certificates indicated infertility treatment were invited to enroll their children in the study, as were all parents of twins and other multiples. The researchers also recruited roughly three times as many singletons not conceived via infertility treatment. Four months after giving birth, the mothers indicated on a questionnaire the type of infertility treatment they received:

Keyword: Development of the Brain
Link ID: 21755 - Posted: 01.07.2016

Laura Sanders It didn’t take a lot of brainpower to come up with the name for a nerve cell that looks like a bushy, round tangle of fibers perched atop a nucleus. Meet the shrub cell. This botanically named cell, discovered in the brains of adult mice, made its formal debut in the Nov. 27 Science. The newly described cell lives in a particular nervy neighborhood — an area called layer 5 in the part of the brain that handles incoming visual information. Xiaolong Jiang of Baylor College of Medicine in Houston and colleagues defined shrub cells and other newcomers by their distinct shapes, their particular connections to other nerve cells or their similarities to nerve cells found elsewhere. Joining shrub cells are the freshly named horizontally elongated cells, deep-projecting cells, L5 basket cells and L5 neurogliaform cells. Each is an interneuron, a middleman that connects nerve cells to each other. The finding highlights the stunning variety of shapes and wiring patterns of cells in the brain. Citations X. Jiang et al. Principles of connectivity among morphologically defined cell types in adult neocortex. Science. Vol. 350, November 27, 2015. doi: 10.1126/science.aac9462 © Society for Science & the Public 2000 - 2015.

Keyword: Development of the Brain
Link ID: 21754 - Posted: 01.07.2016

by Helen Thompson Earth’s magnetic field guides shark movement in the open ocean, but scientists had always suspected that sharks might also get their directions from an array of other factors, including smell. To sniff out smell’s role, biologists clogged the noses of leopard sharks (Triakis semifasciata), a Pacific coastal species that makes foraging trips out to deeper waters. Researchers released the sharks out at sea and tracked their path back to the California coast over four hours. Sharks with an impaired sense of smell only made it 37.2 percent of the way back to shore, while unimpaired sharks made it 62.6 percent of the way back to shore. The study provides the first experimental evidence that smell influences a shark’s sense of direction, the team writes January 6 in PLOS ONE. The animals may be picking up on chemical gradients produced by food sources that live on the coast. © Society for Science & the Public 2000 - 2015.

Keyword: Chemical Senses (Smell & Taste); Animal Migration
Link ID: 21753 - Posted: 01.07.2016