Links for Keyword: Miscellaneous

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Maybe You Do Need a Hole in Your Head—to Let the Medicine In

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.

Decoding the Brain’s Cacophony

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

Benjamin Franklin to Victor Frankenstein

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

Man’s Serious Illness Shows the Danger of Daring to Eat a Garden-Variety Slug

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

Really? The Claim: Yawning Cools the Brain

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

Longevity genes challenged

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,

Brain-Eating Amoeba Thrives in Warm, Fresh Water

By Jennifer Viegas The brain-eating amoeba that killed three people this summer is an organism that thrives in warm fresh water and can be found in lakes, rivers, hot springs and soil, according to the Centers for Disease Control and Prevention. All three deaths this year occurred in the South: a 16-year-old girl in Florida, a 9-year-old boy in Virginia and a 20-year-old man in Louisiana. A brutal summer and drought make the conditions perfect for the amoeba. The threat of N. fowleri could potentially be elevated for weeks in some areas. According to the CDC, infections occur mainly in July, August and September. The microscopic amoeba, Naegleria fowleri, attacks anyone who has the misfortune of inhaling it. It enters first up the nose and then goes to the brain, usually killing its victims within two weeks. "Once forced up the nose, it can travel to the brain, where it digests brain cells," Jonathan Yoder, an epidemiologist at the Centers for Disease Control and Prevention, told Discovery News. "It's a very tragic disease that thankfully is very rare." Aside from its rarity, the amoeba "is not looking to prey upon human victims," he said. "They usually go after bacteria in water and soil." © 2011 Discovery Communications, LLC.

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 15693 - Posted: 08.20.2011

'Brain Culture': How Neuroscience Became a Pop Culture Fixation

By Maria Popova Far from a mere motherboard, the brain has swollen into one of humanity's greatest obsessions. We have been trying to visualize it since antiquity, we have written countless books about it, we've even enlisted it in our pop culture satire. The brain, in fact, has become a pop culture fixture in and of itself. That's exactly what Davi Johnson Thornton explores in Brain Culture: Neuroscience and Popular Media -- a fascinating account of the rhetoric and sociology of cognitive science, exploring our culture's obsession with the brain and how we have elevated the vital organ into cultish status, mythologizing its functions and romanticizing the promise of its scientific study. The brain, it seems, has become a modern muse. (As Jonah Lehrer brilliantly notes in his Wired interview with Thornton, "If Warhol were around today, he'd have a series of silkscreens dedicated to the cortex; the amygdala would hang alongside Marilyn Monroe.") From the media's propensity for pretty pictures like PET and fMRI scans, often misinterpreted or presented out of context to the misappropriation of the language of neuroscience in simplistic self-help narratives to the "anxious parenting" triggered by the facile findings of developmental cognitive science, Thornton offers a refreshing lens on the many contradictions in how we think about the brain as we continue to hope that making the brain calculable and mappable would also make it manipulable in precisely the ways we need it to be. What makes Thornton's take most compelling is the lucidity with which she approaches exactly what we know and don't know about the brain. Every day, we're bombarded with exponentially replicating headlines about new "sciences" like neuromarketing, which, despite the enormous budgets poured into them by the world's shortcut-hungry Fortune 500, remain the phrenology of our time, a tragic manifestation of the disconnect between how much we want to manipulate the brain and how little we actually know about its intricately connected, non-compartmentalizable functions. © 2011 by The Atlantic Monthly Group

Neuroscience in China: Growth factor

David Cyranoski Mu-ming Poo leads a double life. For three weeks every month, he works in a cramped, cluttered office at the University of California, Berkeley. Looking drab in his dark-green pullover, olive trousers and black Adidas sports shoes, the 62-year-old neuroscientist slumps slightly in his chair. In the adjoining laboratory, half a dozen postdoctoral researchers, expected to work independently, go quietly about their business. Cut to Shanghai, China, where Poo spends the remaining quarter of his time. In the director's office at the Institute of Neurosciences (ION), he sports a pressed, light-blue shirt neatly tucked into belted trousers (same trainers). With few books and papers about, the room seems more spacious than its Californian counterpart; mangoes and other fruit in a bowl provide a tasteful flourish. Here, Poo supervises only one postdoctoral researcher, but a dozen chattering graduate students are stuffed into an office, waiting for the hour that he sets aside for each one during his whirlwind visits. Poo sits straighter, talks faster and seems more alert, alive — younger, even. As stimulating as he finds his research in the United States, where he is a member of the National Academy of Sciences, Poo finds a sense of mission in China. "It's more exciting, exhilarating here," he says. "They need me. I feel it's the best use of my life." China is alive with possibilities in science, but realizing them is a complicated affair. The country's fondness for speed — for short-term achievements and, increasingly, short-term profits — has worked relatively well in the chemical and physical sciences and in large-scale genomics, where researchers can systematically tick off the chemical compounds or genetic sequences that they have produced (see 'Eastern promise'). © 2011 Nature Publishing Group,

The bacteria (or virus or parasite) made me do it

By Ben Harder, Those who believe in free will might be troubled to learn a few secrets about viruses, bacteria and parasites. While it may sound like science fiction, science hints at the potential for microbes to influence our minds, or at least our behavior. Granted, with very limited exceptions, there’s no conclusive proof that foreign agents can control us from within. But when you consider the evidence with an open mind, it’s interesting to consider the possibilities. The latest relevant finding seems innocuous enough. Last month, three insect and plant disease researchers in the University of California system reported a discovery about the tomato spotted wilt virus. As its name suggests, this virus infects and damages tomato plants. It’s harmless to people. To jump from plant to plant, the virus relies on insects known as thrips. A thrip feeds by sticking its oral probe into a plant’s cells and sucking out the contents. If a cell happens to contain the virus, the thrip sucks it up, too. Scientists already knew that virus-infected tomato plants are more appealing to thrips than uninfected plants. The California researchers discovered something else: Once a thrip consumes the virus, its behavior changes. It spends more time feeding, and it licks more plant cells in the process, coating the next tomato plant with the virus. © 1996-2011 The Washington Post

Related chapters from BP7e: Chapter 1: Biological Psychology: Scope and Outlook; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 1: An Introduction to Brain and Behavior; Chapter 11: Emotions, Aggression, and Stress
Link ID: 15451 - Posted: 06.18.2011

Top Ten Myths About the Brain

By Laura Helmuth 1. We use only 10 percent of our brains. This one sounds so compelling—a precise number, repeated in pop culture for a century, implying that we have huge reserves of untapped mental powers. But the supposedly unused 90 percent of the brain is not some vestigial appendix. Brains are expensive—it takes a lot of energy to build brains during fetal and childhood development and maintain them in adults. Evolutionarily, it would make no sense to carry around surplus brain tissue. Experiments using PET or fMRI scans show that much of the brain is engaged even during simple tasks, and injury to even a small bit of brain can have profound consequences for language, sensory perception, movement or emotion. True, we have some brain reserves. Autopsy studies show that many people have physical signs of Alzheimer’s disease (such as amyloid plaques among neurons) in their brains even though they were not impaired. Apparently we can lose some brain tissue and still function pretty well. And people score higher on IQ tests if they’re highly motivated, suggesting that we don’t always exercise our minds at 100 percent capacity. 2. “Flashbulb memories” are precise, detailed and persistent. We all have memories that feel as vivid and accurate as a snapshot, usually of some shocking, dramatic event—the assassination of President Kennedy, the explosion of the space shuttle Challenger, the attacks of September 11, 2001. People remember exactly where they were, what they were doing, who they were with, what they saw or heard. But several clever experiments have tested people’s memory immediately after a tragedy and again several months or years later. The test subjects tend to be confident that their memories are accurate and say the flashbulb memories are more vivid than other memories. Vivid they may be, but the memories decay over time just as other memories do. People forget important details and add incorrect ones, with no awareness that they’re recreating a muddled scene in their minds rather than calling up a perfect, photographic reproduction.

Related chapters from BP7e: Chapter 1: Biological Psychology: Scope and Outlook; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 1: An Introduction to Brain and Behavior; Chapter 13: Memory, Learning, and Development
Link ID: 15371 - Posted: 05.28.2011

How the Brain Got Its Buttocks

By Jesse Bering There are so many obscure specializations, subspecializations and subcortical subspecializations within the brain sciences that even the sharpest brain has scarcely enough brainpower to learn everything there is to know about itself. But if there's one fact that the teacup-Yorkie-sized prune in your head might want to ponder, it's that it shares a peculiar past with something considerably lower in your anatomy—your genitalia. I don't mean that our brains and reproductive organs share some embryological or evolutionary history, but rather that they were once (and, to some extent, still are) entwined in the language of the body. What this odd story reveals is that the ancient anatomists were major dickheads. We all were, back then. Régis Olry, of the University of Quebec, and Duane Haines, of the University of Mississippi, brought the whole sordid tale to light in an intriguing pair of articles for the Journal of the History of the Neurosciences. These "historians of neuroanatomy" (yes, there is such a profession, and we should be grateful for it) reviewed a very old, circuitous medical literature and found that the human brain was once described as comprising its very own vulva, penis, testicles, buttocks, and even an anus. In fact, part of the cerebrum is still named in honor of long-forgotten whores. In their first article from 1997, epochs ago in academic terms, Olry and Haines revealed the surprising origins of the term "fornix." For those illiterate in neuroanatomy, which I'll assume is 99.9 percent of you, the fornix is a fibrous, arching band of nerve fibers that connects the hippocampus and the limbic system, and spans certain fluid-filled chambers of the brain known as ventricles. You'd have numerous and noticeable problems if your fornix weren't functioning properly, including serious impairments in spatial learning and overall navigation. © 2011 The Slate Group, LLC

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: 15346 - Posted: 05.21.2011

Teamwork keeps fire ants high and dry

By Daniel Strain Fire ants know how to survive when the waters rise: They turn their bodies into life rafts. A new study explores the physics that keeps fire ant lifeboats, waterborne colonies sometimes containing tens of thousands of bugs, afloat. Linked together, the ants can form a watertight seal that keeps them from drowning, engineers from the Georgia Institute of Technology in Atlanta report the week of April 25 in the Proceedings of the National Academy of Sciences. And the whole is bigger than the sum of its parts, says Julia Parrish, a zoologist at the University of Washington in Seattle: "The properties the group displays are not necessarily predictable by just looking at one individual." Fire ants (Solenopsis invicta), an invasive species around much of the globe, are well-prepared for disaster. When their Brazilian homes flood, entire colonies — including queens, workers and workers carrying larvae — take to the sea. "They have to stay together as a colony to survive," says study coauthor Nathan Mlot of Georgia Tech. Their double-decked rafts — about half the ants float on the bottom holding the rest up — can bob along for days or even weeks. The ants' seafaring success comes down to both small and big properties. On the small scale, single ants can walk on water, at least to a degree, similar to a floating pin or a water-striding insect. When wet, fire ants can also capture tiny air bubbles, probably thanks to the thin layers of hair covering their bodies, giving these intrepid mariners added buoyancy. © Society for Science & the Public 2000 - 2011

Related chapters from BP7e: Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 0:
Link ID: 15264 - Posted: 04.26.2011

World's first human brain map unveiled

Hayley Crawford, reporter The world's first computerised map of the brain was released yesterday by scientists at the Allen Institute for Brain Science, in Seattle, Washington, after more than four years of cutting-edge research. The Human Brain Atlas is an interactive research tool that will help scientists to understand how the brain works and aid new discoveries in disease and treatments. The information used to build it comes from the analysis of two human brains, using magnetic resonance imaging (MRI) and a variation of MRI called diffusion tensor imaging. Allan Jones, the CEO of the institute, told Wired how the brains were also chopped up into small pieces, and RNA extracted from the tissue. They used this RNA to obtain a read-out of the 25,000 genes in the human genome. All this information was put together to create a detailed map of the brain. One thousand anatomical sites in the brain can be searched, supported by more than 100 million data points that indicate the gene expression and biochemistry of each site. For example, a researcher could quickly create a 3D snapshot (see image below) of all the locations in the brain where Prozac's biochemical targets are expressed. Prozac-target.jpg © Copyright Reed Business Information Ltd.

Mind controls: Eight new tools to boost your brain

by Clare Wilson I'M WATCHING this revolution exploding around me," says Mark George, a neuropsychiatrist at the Medical University of South Carolina in Charleston. "I'm like a kid in a candy store." George is referring to his role as editor-in-chief of Brain Stimulation, a journal launched three years ago to cover the growing list of technologies that can alter the brain's electrical activity. The tools involved range from electrodes and optical fibres to magnetic fields and sound waves, but they all give neuroscientists the power to fine-tune the brain's activity, making them computer hackers of the mind. Fifteen years ago, only a couple of such technologies existed and they were seen as experimental techniques on the fringes of neuroscience. Today there are at least eight methods, all with their own pros and cons, and some are on the verge of becoming mainstream treatments for Parkinson's disease, epilepsy and depression. Innumerable more uses are being explored. Until recently the only treatments available for conditions affecting the brain were drugs or surgery - a "hammer over the head approach", according to William Tyler, a biomedical engineer at Virginia Tech Carilion Research Institute in Roanoke and a pioneer of the new brain stimulation techniques. © Copyright Reed Business Information Ltd.

Cellphone Radiation May Alter Your Brain. Let’s Talk.

By KATE MURPHY In a culture where people cradle their cellphones next to their heads with the same constancy and affection that toddlers hold their security blankets, it was unsettling last month when a study published in The Journal of the American Medical Association indicated that doing so could alter brain activity. The report said it was unclear whether the changes in the brain — an increase in glucose metabolism after using the phone for less than an hour — had any negative health or behavioral effects. But it has many people wondering what they can do to protect themselves short of (gasp) using a landline. “Cellphones are fantastic and have done much to increase productivity,” said Dr. Nora Volkow, the lead investigator of the study and director of the National Institute of Drug Abuse at the National Institutes of Health. “I’d never tell people to stop using them entirely.” Yet, in light of her findings, she advises users to keep cellphones at a distance by putting them on speaker mode or using a wired headset whenever possible. The next best option is a wireless Bluetooth headset or earpiece, which emit radiation at far lower levels. If a headset isn’t feasible, holding your phone just slightly away from your ear can make a big difference; the intensity of radiation diminishes sharply with distance. “Every millimeter counts,” said Louis Slesin, editor of Microwave News, an online newsletter covering health and safety issues related to exposure to electromagnetic radiation. © 2011 The New York Times Company

Can't dance? Brain chemical throws off your groove

By Bill Briggs All these years, I thought it was because I was white. And straight. And old. Sure, I’ll get my freak on if I hear “Disco Inferno,” or when Mary J. is in the spot. (Told you I was old. And let me add: Don’t need no hateration.) But my steps aren’t smooth. Those beats and my body never truly connect -- despite what the cocktails tell me. On the dance floor, I'm the male Elaine from "Seinfeld," all kicks, thumbs and no rhythm. Turns out, it’s all in my head, not my hips or feet. A study, released today by researchers at the University of Oxford in England, claims a tiny messenger in the brain is partly to blame for those among us who struggle to grasp the latest dance moves. This is all about GABA (short for gamma-aminobutyric acid). Again: not Gaga, GABA. A naturally occurring chemical, GABA is a bit like the brain’s traffic cop. Nerve cells in the brain are constantly firing and “talking” to each other. GABA helps keep all that chatter from getting out of control. “Our research suggests that an important first step in learning that new skill is a decrease in GABA levels in the motor cortex,” explained Dr. Charlotte Stagg, a junior research fellow at Oxford and at John Radcliffe Hospital. Her study was published online in the journal Current Biology. © 2011 msnbc.com

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 15084 - Posted: 03.08.2011

The brain engineer: Shining a light on consciousness

by Rowan Hooper Neuroengineer Ed Boyden is best known for his pioneering work on optogenetics, which allows brain cells to be controlled using light. A speaker at the TED2011 conference this week, his vision, he tells Rowan Hooper, is nothing less than to understand the brain, treat neural conditions and figure out the basis of human existence. Give us your elevator pitch. I run the synthetic neurobiology group. We develop software, electrical and optical tools to allow people to analyse brain dynamics. Unlike a computer, the brain is made of thousands of different types of cell, and we don't know how they work. We need to be able to turn the cells on and off to see how they cooperate to implement brain computations, and how they go awry in brain disorders. What we're doing is making genetically encoded neurons that we can turn on and off with light. By shining light on these cells we can activate them and see what they do. What brain functions will this allow you to study? Scientists now have unprecedented abilities to perturb and record from the brain, and that's allowing us to go after complex ideas like thought and memory. Our tools will help us parse out emotion, memory, attention and consciousness. Put psychology and neuroscience together with neuroengineering, and some of the biggest questions in neuroscience become tractable. Tell us about your tools. The core idea is to take molecules that sense light and convert it into electrical energy, and put them in neurons. We can take a given class of brain cells and develop a virus to deliver genes to these cells. Then we can shine light on these cells and activate them and see what they do. © Copyright Reed Business Information Ltd.

NIH-funded study shows early brain effects of HIV in mouse model

A new mouse model closely resembles how the human body reacts to early HIV infection and is shedding light on nerve cell damage related to the disease, according to researchers funded by the National Institutes of Health. The study in today’s Journal of Neuroscience demonstrates that HIV infection of the nervous system leads to inflammatory responses, changes in brain cells, and damage to neurons. This is the first study to show such neuronal loss during initial stages of HIV infection in a mouse model. The study was conducted by a team of scientists from the University of Nebraska Medical Center, Omaha, and the University of Rochester Medical Center, N.Y. It was supported by the National Institute on Drug Abuse (NIDA), the National Institute of Neurological Disorders and Stroke, the National Institute of Mental Health, and the National Center for Research Resources. "This research breakthrough should help us move forward in learning more about how HIV affects important brain functioning in its initial stages, which in turn could lead us to better treatments that can be used early in the disease process," said Dr. Nora D. Volkow, director of NIDA. "The work contained within this study is the culmination of a 20-year quest to develop a rodent model of the primary neurological complications of HIV infection in humans," said Dr. Howard Gendelman, one of the primary study authors. "Previously, the rhesus macaque was the only animal model for the study of early stages of HIV infection. However, its use was limited due to expense and issues with generalizing results across species. Relevant rodent models that mimic human disease have been sorely needed."

Cellphone Use Tied to Changes in Brain Activity

By TARA PARKER-POPE Researchers from the National Institutes of Health have found that less than an hour of cellphone use can speed up brain activity in the area closest to the phone antenna, raising new questions about the health effects of low levels of radiation emitted from cellphones. The researchers, led by Dr. Nora D. Volkow, director of the National Institute on Drug Abuse, urged caution in interpreting the findings because it is not known whether the changes, which were seen in brain scans, have any meaningful effect on a person’s overall health. But the study, published Wednesday in The Journal of the American Medical Association, is among the first and largest to document that the weak radio-frequency signals from cellphones have the potential to alter brain activity. “The study is important because it documents that the human brain is sensitive to the electromagnetic radiation that is emitted by cellphones,” Dr. Volkow said. “It also highlights the importance of doing studies to address the question of whether there are — or are not — long-lasting consequences of repeated stimulation, of getting exposed over five, 10 or 15 years.” Although preliminary, the findings are certain to reignite a debate about the safety of cellphones. A few observational studies have suggested a link between heavy cellphone use and rare brain tumors, but the bulk of the available scientific evidence shows no added risk. Major medical groups have said that cellphones are safe, but some top doctors, including the former director of the University of Pittsburgh Cancer Center and prominent neurosurgeons, have urged the use of headsets as a precaution. © 2011 The New York Times Company

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