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By Ferris Jabr Over the years, I have taught my copy of Microsoft Word a lot of neuroscience terminology: amygdala, corpus callosum, dendritic spines, voxel. But it always knew what neuron meant. I thought I did too. Neurons—the electrically excitable cells that make up the brain and nervous system—first fascinated me in high school. In college, like so many other students studying the brain, I dutifully memorized the structure of the archetypal neuron. I also remember learning about a few different types of neurons with different shapes and functions: motor neurons that make muscles twitch, for example, and unique sensory neurons in the eyes and nose. Only recently, however, have I begun to recognize and appreciate the extraordinary diversity of cells in the nervous system—cells that differ from one another more than the cells of any other organ. Some neurons send electrical signals along fibers that stretch several feet; other neurons’ branches extend only a few millimeters away from the cell body. Some neurons possess a fractal beauty similar to that of ferns and corals: Purkinje cells, for example, often sport finely branched nets, like a sea fan. But some of their neighbors look more like tangled tumbleweeds. One neuron might appear more or less round under the microscope—like a firework frozen in climax—whereas another might spider through the brain like a daddy longlegs. Neurons not only differ in shape—different types of neurons turn on different sets of genes and not all neurons use the same chemicals to communicate. Excitatory neurons mostly stimulate other cells; inhibitory neurons prefer to stifle. Most neurons fire in patterns, but their tempos vary: some keep a steady beat, others remain largely silent except for the occasional burst of activity and still other cells continually fire like a trigger-happy toddler playing laser tag. To summarize: not all neurons are exactly alike. The brain contains multitudes. mouse-neurons © 2012 Scientific American,

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 15: Language and Our Divided Brain
Link ID: 16794 - Posted: 05.15.2012

By Gary Stix “Superwoman has been rumbled,” declared a Daily Telegraph article in 2001 that chronicled how the human brain’s inability to “multitask” undercuts the prospects for a woman to juggle career and family with any measure of success. The brain as media icon has emerged repeatedly in recent years as new imaging techniques have proliferated—and, as a symbol, it seems to confuse as much as enlighten. The steady flow of new studies that purport to reduce human nature to a series of illuminated blobs on scanner images have fostered the illusion that a nouveau biological determinism has arrived. More often than not, a “neurobiological correlate”— tying together brain activity with a behavioral attribute (love, pain, aggression)—supplies the basis for a journal publication that translates instantly into a newspaper headline. The link between blob and behavior conveys an aura of versimilitude that often proves overly seductive to the reporter hard up to fill a health or science quota. A community of neuroscience bloggers, meanwhile, has taken on the responsibility of rectifying some of these misinterpretations. A study published last week by University College of London researchers—“Neuroscience in the Public Sphere”—tried to imbue this trend with more substance by quantifying and formally characterizing it. “Brain-based information possesses rhetorical power,” the investigators note. “Logically irrelevant neuroscience information [the result of the multitude of correlations that turn up] imbues an argument with authoritative, scientific credibility.” © 2012 Scientific American,

Related chapters from BP7e: Chapter 1: Biological Psychology: Scope and Outlook
Related chapters from MM:Chapter 1: An Introduction to Brain and Behavior
Link ID: 16754 - Posted: 05.05.2012

In his second year of neuroscience grad school, Greg Dunn was moonlighting with a different kind of experiment: blowing ink across pieces of paper. The neuron-like pattern it formed was instantly recognizable to him as a neuroscientist. "Ink spreads because it wants to go in the direction of less resistance, and that's probably also the case of when branches grow or neurons grow," he says. "The reason the technique works really well is because it's directly related to how neurons are actually behaving." Dunn calls this the "fractal solution to the universe," which he sees as the "fundamental beauty of nature." He's fascinated that this branching pattern holds true across orders of magnitude, whether that's nanometers for neurons, centimeters for ink, or meters for a tree branch. Since graduating with his PhD last fall, Dunn has continued to spend his days with neurons--big, golden ones ten thousand times the size of neurons in your brain. The former University of Pennsylvania grad student now creates paintings of neurons for a living. © 2012, Kalmbach Publishing Co.

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System
Link ID: 16730 - Posted: 05.01.2012

By Scicurious I’m sitting here, preparing to write a blog post on thermoregulation. I finished a good run a while ago. The temperatures outside weren’t too extreme (50ish degrees F, so comfortable for a good run), and I was sweating freely when I finished. About an hour later, here I am, in fleecey pants, shirt, socks, hoodie…and sleeping bag. And afghan. And cat. I’m freezing. Really, seriously cold. My nailbeds are almost purple, my hands are like ice, and I’ve got goosebumps all over. I’m almost too cold to shiver. This happens every time I run more than about 5 miles. It happens winter or summer (I think winter is worse, usually in summer it’s a relief!). I’ll go out, run 5 or more miles, come home sweaty and glowing with my happy runner’s high, and about 30 minutes later, once all the sweat is dried, I’ll descend into what I call the “post-run shivers”. They last up to two hours after the run, and are the reason I keep my sleeping bag close to hand. When I’ve asked other runners about it, many of them are mystified. Some of them have only experienced the hot feeling post-run, and tell me they can’t shower immediately, or they’ll come out still sweating! But a few others know what I mean. And I’ve always wondered, what is happening to me? Is it normal? Is it ok? When I learned about how humans regulate their body temperature, I learned that we have a natural temperature “set point” of around 37 degrees Celsius (98.6 degrees Fahrenheit), based in the hypothalamus of our brains, and your body regulates its temperature around that set point. © 2012 Scientific American,

Related chapters from BP7e: Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 16586 - Posted: 03.29.2012

By Stephen Dougherty In the film Amèlie, the main character is a young eccentric woman who attempts to change the lives of those around her for the better. One day Amèlie finds an old rusty tin box of childhood mementos in her apartment, hidden by a boy decades earlier. After tracking down Bretodeau, the owner, she lures him to a phone booth where he discovers the box. Upon opening the box and seeing a few marbles, a sudden flash of vivid images come flooding into his mind. Next thing you know, Bretodeau is transported to a time when he was in the schoolyard scrambling to stuff his pockets with hundreds of marbles while a teacher is yelling at him to hurry up. We have all experienced this: a seemingly insignificant trigger, a scent, a song, or an old photograph transports us to another time and place. Now a group of neuroscientists have investigated the fascinating question: Can a few neurons trigger a full memory? In a new study, published in Nature, a group of researchers from MIT showed for the first time that it is possible to activate a memory on demand, by stimulating only a few neurons with light, using a technique known as optogenetics. Optogenetics is a powerful technology that enables researchers to control genetically modified neurons with a brief pulse of light. To artificially turn on a memory, researchers first set out to identify the neurons that are activated when a mouse is making a new memory. To accomplish this, they focused on a part of the brain called the hippocampus, known for its role in learning and memory, especially for discriminating places. Then they inserted a gene that codes for a light-sensitive protein into hippocampal neurons, enabling them to use light to control the neurons. © 2012 Scientific American

Related chapters from BP7e: Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 16582 - Posted: 03.29.2012

By ABIGAIL ZUGER, M.D. Like creatures battling undersea, pro-life and right-to-die forces are locked in mortal but only intermittently visible combat. The last prominent battle ended almost seven years ago, after the death of Terri Schiavo, the Florida woman with brain damage whose feeding tube was removed by court order in the spring of 2005. Since then, all has been quiet on the surface, belying the continuing turmoil in hospitals and courtrooms over what, exactly, marks the end of life. Invariably, the louder the background tumult, the more useful is the quiet, dispassionate narrative. And so one turns to Dick Teresi’s new book with considerable hope: Surely Mr. Teresi, a veteran science journalist, past editor in chief of Science Digest and Omni, will be the ideal guide through those dim purgatories where life and death can be difficult to distinguish. All starts out promisingly enough. An indefatigable researcher and fluid writer, Mr. Teresi provides a good long riff on death past and present, from the Egyptian mummies, dehydrated into “the deadest people on the planet,” to the ever-hopeful terminally ill of our own age, still flossing their teeth and eating healthy meals in hospice care. Mr. Teresi points out that conclusive signs of death have always been subject to debate. All the great civilizations argued about them, with various expert commentators proposing various fail-safe criteria and yet (Mr. Teresi notes with some pleasure) specifying that they themselves should be left unburied for a few days just to avoid any unfortunate mistakes. © 2012 The New York Times Company

Related chapters from BP7e: Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Related chapters from MM:Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 16578 - Posted: 03.27.2012

Greg Gage is on a mission to get kids excited about neuroscience by helping them understand how the brain works — in ways that are extremely memorable. He sells $100 kits that teach how neurons work by putting electricity through cockroach limbs and living cockroaches. One of the most amazing and unexpected experiences I had at the TED conference a couple weeks ago was getting to do one of Gage’s experiments myself. I tracked him down after reading that he was one of 25 invited TED fellows, and before I knew it, I was in a random hallway in the bowels of the convention center, wrestling a squirmy cockroach into my own experiment. First, Gage had me anesthetize a cockroach by dousing it in a glass of ice water, then sever one of its legs (they grow back), plug in a couple of electrodes, and then listen and watch neurons through an app on his iPad. There’s actually a really great video of this same experiment, taken from when Gage performed it for an audience of kids. TED just released it today, as part of its new education initiative. In the video, Gage shows how the living neurons in the cockroach leg can be pulsed with bass from music, and then brings out a live beatboxer on stage to show the cockroach leg dancing to the beat. Read that last sentence again, or just watch the video. It’s pretty crazy. © 2005-2012 Dow Jones & Company Inc.

Related chapters from BP7e: Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Related chapters from MM:Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 16503 - Posted: 03.13.2012

How many neurons are there in the human brain? It was a question that scientists thought they had nailed – and the answer was 100bn (give or take). If you went looking you would find that figure repeated widely in the neuroscience literature and beyond. But when a researcher in Brazil called Dr Suzana Herculano-Houzel started digging, she discovered that no one in the field could actually remember where the 100bn figure had come from – let alone how it had been arrived at. So she set about discovering the true figure (HT to the excellent Nature neuroscience podcast NeuroPod). This involved a remarkable – and to some I suspect unsettling – piece of research. Her team took the brains of four adult men, aged 50, 51, 54 and 71, and turned them into what she describes as "brain soup". All of the men had died of non-neurological diseases and had donated their brains for research. "It took me a couple of months to make peace with this idea that I was going to take somebody's brain or an animal's brain and turn it into soup," she told Nature. "But the thing is we have been learning so much by this method we've been getting numbers that people had not been able to get … It's really just one more method that's not any worse than just chopping your brain into little pieces." She told me that so far, she has only looked at four brains, all of them from men. © 2012 Guardian News and Media Limited

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 1: Biological Psychology: Scope and Outlook
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 1: An Introduction to Brain and Behavior
Link ID: 16451 - Posted: 03.01.2012

By Theodoric Meyer Fifty-five high school students sat silently in a Columbia University auditorium on Saturday afternoon, listening to the first question: “About how many cells are in the human brain?” The room echoed with a slight scraping sound as the students scribbled out their answers on brightly colored sheets of paper, then fell silent again. “The answer,” Michael E. Goldberg, a professor of neuroscience at Columbia, said into a microphone, “is 100 million.” It was the first of many questions to test students’ knowledge of neuroscience in this year’s New York City Regional Brain Bee, which drew students from each borough and Westchester County. The contest works a bit like its more familiar cousins, the spelling and geography bees: Eight rounds, five questions each. Thirty seconds to answer. Spelling, however, doesn’t count. The first two rounds proved fairly easy. Students needed to get only two of the five questions correct to move on, and only a few of them were eliminated. But the competition picked up during the third and fourth rounds, when students needed three correct answers for each round. Dr. Goldberg, a diminutive man in a tweed coat with black-framed glasses and thick white hair, seemed to relish his role as moderator and often supplied scientific asides to the questions. © Copyright 2012 The New York Times Company

Related chapters from BP7e: Chapter 1: Biological Psychology: Scope and Outlook
Related chapters from MM:Chapter 1: An Introduction to Brain and Behavior
Link ID: 16349 - Posted: 02.07.2012

A suburban Chicago man accidentally shot a 3.25in (8.25cm) nail into his skull but is recovering after doctors successfully removed it from the centre of his brain. Dante Autullo, 34, was in his workshop when a nail gun recoiled near his head. But he had no idea the nail had entered his brain until the next day, when he began feeling nauseous. Doctors told Mr Autullo that the nail came within millimetres of the area used for motor function. His fiancee, Gail Glaenzer, told the Associated Press on Friday that he was in good spirits after the two-hour surgery to remove the nail at Advocate Christ Medical Center in Oak Lawn, Illinois. "He feels good. He moved all his limbs, he's talking normal, he remembers everything," she said. "It's amazing, a miracle." Ms Glaenzer said she had no idea the nail had entered his skull when she cleaned a cut on his forehead. BBC © 2012

Related chapters from BP7e: Chapter 1: Biological Psychology: Scope and Outlook
Related chapters from MM:Chapter 1: An Introduction to Brain and Behavior
Link ID: 16282 - Posted: 01.23.2012

By Sora Song The Louisiana Department of Health and Hospitals is warning people against the improper use of neti pots, following the deaths of two people who were infected with Naegleria fowleri — the so-called “brain-eating amoeba” — after using tap water to irrigate their sinuses. A 53-year-old woman from De Soto Parish and a 20-year-old man from St. Bernard Parish both died after using contaminated water in their neti pots, a popular home remedy that looks like a genie’s lamp and is used for flushing out mucus from the nose and sinuses. “If you are irrigating, flushing or rinsing your sinuses, for example, by using a neti pot, use distilled, sterile or previously boiled water to make up the irrigation solution,” said Louisiana State Epidemiologist, Dr. Raoult Ratard. Tap water is safe for drinking, but not for irrigating your nose, Ratard said. It’s also important to rinse the neti pot after each use and leave it open to air dry. Typically, Naegleria fowleri infection occurs when people go swimming or diving in warm freshwater lakes and rivers, particularly in summer in the southern U.S. Last summer, at least three other people died from Naegleria fowleri infection in Florida, Virginia and Kansas. The amoeba enters through the nose, travels to the brain and starts eating neurons. It sounds scary — and it is — but it’s also exceedingly rare. In the 10 years from 2001 to 2010, only 32 infections were reported in the U.S., despite millions of people swimming in lakes and rivers. Of those infected, 30 people were infected by recreational water sources, and two were infected by water from hot springs. © 2011 Time Inc.

Related chapters from BP7e: Chapter 1: Biological Psychology: Scope and Outlook
Related chapters from MM:Chapter 1: An Introduction to Brain and Behavior
Link ID: 16166 - Posted: 12.19.2011

By Alan Boyle Slides containing thin slices of Albert Einstein's brain will go on display at Philadelphia's Mutter Museum, thanks to a donation from a neuropathologist who has been holding onto the samples for decades. Lucy Rorke-Adams of the Children's Hospital of Philadelphia received the box of 46 slides in the mid-1970s from the widow of a physician who helped arrange the preparation of the brain samples, the Philadelphia Inquirer reported. Thomas Stoltz Harvey, a doctor at Princeton Hospital, conducted the autopsy on the famed physicist just hours after his death in 1955. Apparently without the family's permission, Harvey preserved Einstein's brain and sectioned it into hundreds of specimens on microscope slides for study. The controversy, as well as the strange journey of Einstein's brain, are detailed in Michael Paterniti's book "Driving Mr. Albert." Harvey and other researchers found nothing unusual about the brain's size, but there was evidence that Einstein's brain contained more than the expected proportion of glial cells, which play a role in supporting connections between neurons. Rorke-Adams, whose research focuses on comparisons of brain cells at different ages, said Einstein's brain looks remarkably youthful under a microscope: "“It does not show any of the changes that we associate with age," CBS Philly quoted her as saying. © 2011 msnbc.com

Related chapters from BP7e: Chapter 1: Biological Psychology: Scope and Outlook
Related chapters from MM:Chapter 1: An Introduction to Brain and Behavior
Link ID: 16059 - Posted: 11.21.2011

by Elizabeth Norton A loud shirt. A gravelly voice. Purple prose. The merging of the senses, called synesthesia, is a literary device that makes for vivid imagery. But in a neurological condition with the same name, a single perception can involve a second, linked sense that most people would not experience. "Synesthetes" may taste chocolate when hearing a song or see numbers as colors. The reason, new research suggests, may be that the brain cells in the area responsible for the secondary, or extra, sense—for instance, the chocolate taste—are overly active. In addition to shedding light on an unusual mode of perception, the findings could lead to treatments for brain disorders—showing ways to reduce hallucinations, for example, or correcting various types of impaired perception that can follow a stroke. Synesthesia can occur early in life due to the explosive growth of a young child's brain, explains neuroscientist Devin Terhune of the University of Oxford in the United Kingdom. Normally, as the child grows older and brain circuits are refined, the linkages break up. But in synesthetes, for some reason, the secondary sense persists throughout life. The simplest explanation, Terhune and his colleagues believe, is that neurons in the area responsible for the extra sense are more responsive, or "excitable," than usual, strengthening a sensory association that the person wouldn't normally be aware of. The investigators tested their hypothesis with a technique called transcranial magnetic stimulation, which, as the name suggests, stimulates a specific part of the brain with a weak magnetic field applied to the scalp. © 2010 American Association for the Advancement of Science

Related chapters from BP7e: Chapter 8: General Principles of Sensory Processing, Touch, and Pain; Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 7: Vision: From Eye to Brain
Link ID: 16056 - Posted: 11.19.2011

By Science News Staff Cats look to the edge Cats may not seem like planners, but they do look ahead when walking. Three adult cats with magnetic devices strapped to their heads walked across slats, giving scientists the first data on where cats look when they walk. The cats looked a few rungs ahead at the edges of the slats, found Trevor Rivers, now at Bowdoin College in Brunswick, Maine. "They don't say 'I want to step right there.' They are looking at where not to be," Rivers said November 14. — Tina Hesman Saey Moms protected from stress New mothers might not believe it, but being a mom may help protect against some negative consequences of stress. Tracey Shors of Rutgers University in Piscataway, N.J., and colleagues tested the effect of stress on female rats' ability to learn to blink when they hear a particular sound. Stress renders virgin female rats incapable of learning the task. But mothers, including virgin female foster mothers, are protected against learning deficits. And the protection lasts a lifetime, Shors said November 13. The researchers don't yet know what about motherhood is responsible for the protection. — Tina Hesman Saey Vitamin D is good for aging brain Vitamin D may keep mental gears greased during middle age. Middle-aged rats fed high, low or standard amounts of vitamin D performed similarly on memory tests in which the animals had to find a submerged platform in a water tank, Nada Porter of the University of Kentucky and colleagues found. But when the rats had to learn a new location, "the high vitamin D guys just made a beeline" for the new spot while rats in the other two groups swam aimlessly, Porter said during a presentation November 12. — Tina Hesman Saey © Society for Science & the Public 2000 - 2011

Related chapters from BP7e: Chapter 10: Vision: From Eye to Brain; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 7: Vision: From Eye to Brain; Chapter 11: Emotions, Aggression, and Stress
Link ID: 16044 - Posted: 11.17.2011

by Carl Zimmer Neuroscientists these days regularly make spectacular discoveries about how the brain gets sick. They know much more today about brain cancer, Alzheimer’s disease, Parkinson’s disease, and a host of other neurological disorders than they did just a few years ago. And from such discoveries come all sorts of encouraging possibilities for treating or even curing these diseases. If 
only we could break down some rogue protein or bind a drug to 
a troublesome receptor, it seems as if all would be well. There’s just one little hitch: Even if scientists invented the perfect cure, they 
probably couldn’t get it into the brain to do its work. Drugs can cross easily out of the bloodstream into most organs of the body. The brain is a glaring exception because it is protected by an intricate shield known as the blood-brain barrier. The blood-brain barrier serves a vital function: It keeps our brains free for the most part from infections or toxins that find their way into other parts of the body. Unfortunately, the brain’s barrier also gets in the way of most medicines that could help heal it. Neurologists sometimes open up the skull and inject drugs directly. That brute-force approach can work in an emergency, but it is hardly a practical solution for people who need to take drugs every day at home. There is reason for hope that the blood-brain barrier will not block medicine’s path forever, though. Some scientists are working on ways to penetrate it—either by sneaking drugs through the barrier or by temporarily opening channels through which the drugs can pass. © 2011, Kalmbach Publishing Co.

Related chapters from BP7e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 16043 - Posted: 11.17.2011

By BENEDICT CAREY ST. HELENA, Calif. — The scientists exchanged one last look and held their breath. Everything was ready. The electrode was in place, threaded between the two hemispheres of a living cat’s brain; the instruments were tuned to pick up the chatter passing from one half to the other. The only thing left was to listen for that electronic whisper, the brain’s own internal code. The amplifier hissed — the three scientists expectantly leaning closer — and out it came, loud and clear. “We all live in a yellow submarine, yellow submarine, yellow submarine ....” “The Beatles’ song! We somehow picked up the frequency of a radio station,” recalled Michael S. Gazzaniga, chuckling at the 45-year-old memory. “The brain’s secret code. Yeah, right!” Dr. Gazzaniga, 71, now a professor of psychology at the University of California, Santa Barbara, is best known for a dazzling series of studies that revealed the brain’s split personality, the division of labor between its left and right hemispheres. But he is perhaps next best known for telling stories, many of them about blown experiments, dumb questions and other blunders during his nearly half-century career at the top of his field. Now, in lectures and a new book, he is spelling out another kind of cautionary tale — a serious one, about the uses of neuroscience in society, particularly in the courtroom. Brain science “will eventually begin to influence how the public views justice and responsibility,” Dr. Gazzaniga said at a recent conference here sponsored by the Edge Foundation. © 2011 The New York Times Company

Related chapters from BP7e: Chapter 1: Biological Psychology: Scope and Outlook
Related chapters from MM:Chapter 1: An Introduction to Brain and Behavior
Link ID: 15971 - Posted: 11.01.2011

Related chapters from BP7e: Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Related chapters from MM:Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 15969 - Posted: 11.01.2011

By DONALD G. McNEIL Jr. An Australian man has been hospitalized for more than a month in serious condition as a result of eating two garden slugs on a dare, according to Australian news media and ProMED , an online service that tracks disease outbreaks. The 21-year-old Sydney man apparently contracted a rat lungworm parasite from the slugs, which pick it up from rodent droppings. The parasite, a nematode called Angiostrongylus cantonensis, can cause fatal brain swelling. The ProMED moderator who reported the case said the life cycle of the nematode was described in Australia 50 years ago. It infects not just slugs, rats and humans but also dogs, horses, flying fox bats and marsupials like kangaroos. It can also be caught from unwashed vegetables. “We hope this will help to remind others to avoid eating raw slugs,” the moderator, Eskild Petersen, said. The disease is more common in Thailand, where koi-hoi, a dish with raw snail meat, is eaten; residents of Hawaii have been infected by eating improperly washed lettuce with tiny slugs on it. Escargots — snails baked in a garlic butter sauce — are generally safe, although they can trigger shellfish allergies. Snails “ranched” for restaurants (like those pictured above) are raised on clean feed and purged. Garden snails may contain poisons, including snail bait. There has been at least one report of people who developed erratic heart rhythms after eating stew made from snails that had eaten oleander leaves, which contain digoxin, a cardiac drug. © 2011 The New York Times Company

Related chapters from BP7e: Chapter 1: Biological Psychology: Scope and Outlook
Related chapters from MM:Chapter 1: An Introduction to Brain and Behavior
Link ID: 15921 - Posted: 10.18.2011

By ANAHAD O'CONNOR The medical literature is rife with explanations for yawning, but one has gained substantial ground in recent years: This mysterious habit may help regulate brain temperature. The brain operates best within a narrow range of temperatures, and like a car engine, it sometimes needs a way to cool down. To lower the brain’s thermostat, researchers say, the body takes in cooler air from its surroundings — prompting deep inhalation. Yawning is contagious. Simply watching someone do it is enough to induce the behavior. But when scientists had people watch yawning videos in a 2007 study, they found that applying cold packs to the subjects’ heads practically eliminated contagious yawning. Nasal breathing, which also promotes brain cooling, had a similar effect. In a study of 160 people published last month in the journal Frontiers in Evolutionary Neuroscience, yawning was found to vary by season. People were shown to be more likely to yawn in winter than summer, perhaps because an overheated brain gets little relief from taking in air that is warmer than body temperature. The researchers, who controlled for factors like humidity and the amount of sleep subjects got the night before, also found that the more time a person spent outside in warm temperatures, the less likely they were to yawn. The findings may explain why people yawn when tired: Sleep deprivation raises brain temperature. As for why yawning is contagious, it may have evolved as a way to signal to others in a group to stay alert and ready in case of outside attacks, scientists say. © 2011 The New York Times Company

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 15889 - Posted: 10.08.2011

Heidi Ledford A widely touted — but controversial — molecular fountain of youth has come under fire yet again, with the publication of new data challenging the link between proteins called sirtuins and longer lifespan. In a paper published today in Nature1, researchers report that overexpressing a sirtuin gene in two model organisms — the nematode Caenorhabditis elegans and the fruitfly Drosophila melanogaster — does not boost longevity as had been previously reported. Instead, the authors argue that the longer lifespan originally seen was the result of unrelated mutations lurking in the background of the experimental strains. Some see the results as clearing the air, and freeing the field to focus on other effects of sirtuins, such as regulating metabolism and responding to environmental stress. "The field has been overfocused on overhyped claims of longevity," says Johan Auwerx, a researcher at the Federal Institute of Technology in Lausanne, Switzerland, who has worked with the proteins but was not involved with the new study. "I don't think that's the main function of the sirtuins." “It's like discovering a landmine. If you walk by, a lot of other people will get blown up.” But Leonard Guarente, a sirtuin researcher at the Massachusetts Institute of Technology in Cambridge, who published the original C. elegans work in 20012, argues that the longevity link is real and that the new paper is just "a bump in the road". "Our data are rock solid," he says. "I stand by them, and they have been replicated in other labs." © 2011 Nature Publishing Group,

Related chapters from BP7e: Chapter 1: Biological Psychology: Scope and Outlook
Related chapters from MM:Chapter 1: An Introduction to Brain and Behavior
Link ID: 15825 - Posted: 09.22.2011