New research with monkeys has yielded insight into the neural machinery that animals, and possibly humans, use to mentally represent the value of one action over another. Scientists at the Howard Hughes Medical Institute (HHMI) have determined the strategy by which the brain calculates the value of potential behavioral choices as those values change over time with new experience. Their studies, said the cognitive neuroscientists who conducted the research, help in understanding the mysterious process by which animals and humans process sensory input to decide on actions that yield the greatest advantage. The researchers, led by HHMI investigator William Newsome at the Stanford University School of Medicine, published their findings in the June 18, 2004, issue of the journal Science. “Researchers who study behavior regard decision-making as a critical link between the classic fields of the study of perception and the study of motor output,” said Newsome. “Sensory information comes into the brain, and somewhere that information is evaluated and decisions get made about what's out there. For example: Is it a predator? Is it a prey? Is it food or another object?” © 2004 Howard Hughes Medical Institute

Keyword: Vision; Attention
Link ID: 5759 - Posted: 06.24.2010

By MARY DUENWALD Everybody hurts sometimes, and when in pain, most people reach for one of three remedies available on the drugstore shelf: acetaminophen (Tylenol), ibuprofen (Motrin or Advil) and aspirin. These painkillers are the three top-selling over-the-counter drugs, taken by one in five Americans at least once a week. Their sales in the United States totaled $3.2 billion in the last year, according to ACNielsen. People take pain pills not only for headaches but for arthritis pain, fevers and sore backs, among other ailments - and they think they know what they are doing. According to one survey, only a third of people who take drugstore painkillers bother to read the package directions; 64 percent said they were unconcerned about side effects. But many doctors find this level of confidence alarming. Aspirin and other anti-inflammatories can cause bleeding ulcers, raise blood pressure and cause scarring in the esophagus, while acetaminophen, in too-large amounts, can injure the liver. People who take small daily doses of aspirin to prevent heart disease should be especially careful about piling on more pain relievers, which might in some cases cause side effects or interfere with aspirin's heart-saving effects, doctors say. Copyright 2004 The New York Times Company

Keyword: Pain & Touch
Link ID: 5758 - Posted: 07.06.2004

By BONNIE ROTHMAN MORRIS Mention anorexia or bulimia, and what comes to mind is a skin-and-bones teenager caught in a ferocious struggle to be thin. But doctors say they are seeing a disturbing trend: a growing group of women in their 30's, 40's and 50's who have eating disorders. Most have husbands, children, jobs and aging parents. They live with their secret while trying to manage the other aspects of their lives. Lori Varecka, 44, said she hid her bouts of starving and purging from her husband, her mother and her three children for more than two decades. But by 1997, what Mrs. Varecka was hiding was plain to see: At 5 feet 7 inches, she weighed 94 pounds. That year, she admitted to her doctor that she was ill. Eventually, she also told her family. In some cases, experts say, older women with eating disorders know something is wrong, but they do not give a name to their problem. Some feel ashamed to have an illness normally associated with teenagers. "Women feel so invalid. They feel that they should grow up," said Dr. Margo Maine, an eating disorders expert in Hartford and the author of a coming book on midlife eating disorders, "The Shape We're In: Overcoming Women's Obsessions with Weight, Food and Body Image." Copyright 2004 The New York Times Company

Keyword: Anorexia & Bulimia
Link ID: 5757 - Posted: 07.06.2004

By DENISE GRADY They are the building blocks of flab, the wages of cheesecake, the bloated little sacks of grease that make more of us - more than we can fit into our pants. Scorned and despised, they are sucked out surgically by the billions from bulging backsides, bellies and thighs. But they are not without admirers. "Fat cells are beautiful cells to look at," said Dr. Philipp E. Scherer, an associate professor of cell biology and medicine at Albert Einstein College of Medicine in New York. "I've been working with them for 10 years and I still enjoy looking at them." On a recent afternoon at his laboratory, Dr. Scherer slipped a Petri dish of fat cells under a microscope and showed a visitor how strikingly they caught the light and reflected it. Magnified, the cells became a field of glittering rings. A mature fat cell, or adipocyte, contains a huge, clear droplet of fat that takes up nearly the entire cell and shoves the nucleus aside, squashing it up against the membrane so that the cell appears empty. But it's actually a shining sea of fat, stored as molecules of triglyceride. Copyright 2004 The New York Times Company

Keyword: Obesity
Link ID: 5756 - Posted: 07.06.2004

BY FLOYD SKLOOT Since 1990, when she published "A Natural History of the Senses," Diane Ackerman has continued to explore how intimate human experience defies rational explanation. "A Natural History of Love" appeared in 1994. Next came "Deep Play" (1999), an account of human creativity and our need for transcendence, and "Cultivating Delight: A Natural History of My Garden" (2001), about the way gardening elevates our souls. What fascinates Ackerman in these books is the pervasive mystery of nature, despite the increasing depth of our scientific knowledge. Her approach is to select a topic that is in its essence ineffable, then gather information about it from the worlds of science and evolutionary theory, literature, myth, popular culture and personal experience, and lavish her findings with elaborately worked, poetic prose. Her intention is to say the unsayable. Here, for instance, is Ackerman defining memory in her newest book, "An Alchemy of Mind," which considers the human brain and consciousness from her customarily impressionistic mix of perspectives: "An event is such a little piece of time and space, leaving only a mind glow behind like the tail of a shooting star. For lack of a better word, we call that scintillation memory." She is a grand, erudite synthesizer, positioning herself at the place where knowledge ends and reporting back to us in the language of lyric. "I believe consciousness is brazenly physical," she tells her readers, "a raucous mirage the brain creates to help us survive. But I also sense the universe is magical, greater than the sum of its parts." This is not the way things sound in neuroscience journals or philosophy of mind papers. Copyright © 2004, Newsday, Inc.

Keyword: Miscellaneous
Link ID: 5755 - Posted: 06.24.2010

By Rossella Lorenzi, Discovery News — A fly's taste might be much like ours, with the difference that the insect perceives bitter tastes much more accurately, genetic research of the fruit fly's tasting cells suggests. A study of the Drosophila fruit fly's labial palps — the fly's equivalent of a tongue — has revealed that specialized cells on the insect's main taste organ respond to sweet and bitter taste much like the human tongue. "A remarkable convergence of anatomical as well as molecular features of gustatory systems between mammals and insects appear to emerge from our studies," Hubert Amrein, assistant professor of genetics at Duke University Medical Center, Durham, N.C., and lead author of the study, wrote in the journal Current Biology. While in mammals taste receptors (the protein switches that trigger the nerve cells to send signals to the brain in response to food items or other chemicals) are limited to the tongue, in flies they are mounted on bristles found all over the body, including legs and wings. Copyright © 2004 Discovery Communications Inc.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 5754 - Posted: 06.24.2010

CHICAGO – The activity of a brain enzyme known to affect mood may be decreased in teens who commit suicide, according to an article in the July issue of The Archives of General Psychiatry, one of the JAMA/Archives journals. According to the article, approximately 30,000 people die of suicide in the United States annually, and suicide is the second leading cause of death among teenagers. While there is some understanding about the psychological and psychosocial factors associated with teenage suicide, little is known about neurobiological factors that may contribute to teenage suicide. An enzyme in the brain called protein kinase C (PKC) has been linked with mood disorders, and it is the target of some mood-stabilizing drugs. Ghanshyam N. Pandey, Ph.D., of the University of Illinois at Chicago, and colleagues investigated whether there was any link between changes in PKC and teenage suicide. The researchers examined the brains of 17 teenage suicide victims and compared them to 17 brains of teenagers without psychiatric illness who did not commit suicide as their cause of death (control subjects). The brains were obtained from the Brain Collection Program of the Maryland Psychiatric Research Center, in collaboration with the Medical Examiner's Office of the State of Maryland). PCK activity was measured from samples of PKC taken from each brain.

Keyword: Depression; Development of the Brain
Link ID: 5753 - Posted: 06.24.2010

Getting stressed now and again may be good for your health, research suggests. A short burst of stress, such as that caused by sitting an exam, may strengthen your body's immune system. But long-term stress, such as living with a permanent disability, may render you less able to fight infections, say the study authors. Dr Suzanne Segerstrom and Dr Gregory Miller report their findings in the journal Psychological Bulletin. Scientists have known for some time that stress can have a negative effect on the body. Now the American and Canadian pair from the University of Kentucky and the University of British Columbia say some psychological stress can be good for you. They looked at about 300 scientific papers published on the subject, involving almost 19,000 people. Stressful situations that lasted only short periods appeared to tap into the primeval 'fight or flight' response, which dates back to when early man was threatened by predators. This response benefited the person by boosting their body's natural front-line defence against infections from traumas such as bites and scrapes. But long-term anxiety had the opposite effect. (C)BBC

Keyword: Stress; Neuroimmunology
Link ID: 5752 - Posted: 07.05.2004

University of Iowa researchers have shown for the first time that gene therapy delivered to the brains of living mice can prevent the physical symptoms and neurological damage caused by an inherited neurodegenerative disease that is similar to Huntington's disease (HD). If the therapeutic approach can be extended to humans, it may provide a treatment for a group of incurable, progressive neurological diseases called polyglutamine-repeat diseases, which include HD and several spinocerebellar ataxias. The study, conducted by scientists at the UI Roy J. and Lucille A. Carver College of Medicine and colleagues at the University of Minnesota and the National Institutes of Health (NIH), appears in the August issue of Nature Medicine and in the journal's advanced online publication July 4. "This is the first example of targeted gene silencing of a disease gene in the brains of live animals and it suggests that this approach may eventually be useful for human therapies," said senior study author Beverly Davidson, Ph.D., the Roy J. Carver Chair in Internal Medicine and UI professor of internal medicine, physiology and biophysics, and neurology. "We have had success in tissue culture, but translating those ideas to animal models of disease has been a barrier. We seem to have broken through that barrier."

Keyword: Huntingtons; Movement Disorders
Link ID: 5751 - Posted: 07.05.2004

Clear patterns emerge outlining greater damage from chronic stress WASHINGTON — Psychologists have long known that stress affects our ability to fight infection, but a major new “meta-analysis” – a study of studies – has elucidated intriguing patterns of how stress affects human immunity, strengthening it in the short term but wearing it down over time. The report appears in the July issue of Psychological Bulletin, which is published by the American Psychological Association. Major findings are three-fold. First, the overlapping findings of 293 independent studies reported in peer-reviewed scientific journals between 1960 and 2001 – with some 18,941 individuals taking part in all -- powerfully confirm the core fact that stress alters immunity. Second, the authors of the meta-analysis observed a distinctive pattern: Short-term stress actually “revs up” the immune system, an adaptive response preparing for injury or infection, but long-term or chronic stress causes too much wear and tear, and the system breaks down. Third, the immune systems of people who are older or already sick are more prone to stress-related change. Psychologists Suzanne Segerstrom, PhD, of the University of Kentucky, and Gregory Miller, PhD, of the University of British Columbia, analyzed the results of the nearly 300 studies by sorting them into different categories and statistically evaluating relationships. For example, the five stressor categories included: © 2004 American Psychological Association

Keyword: Stress; Neuroimmunology
Link ID: 5750 - Posted: 06.24.2010

By Jennifer Quinn We know torture when we see it - the problem is those meting out the violence often don't. That's the revelatory conclusion of one expert who is attempting to understand the insidious way in which torture becomes "acceptable". It's called degradation, mistreatment, tough interrogation. According to experts, it's often called everything except what it is - torture. "In investigations of US abuse of imprisoned Iraqis, there has been reluctance to use the T-word," Martha Huggins, a sociology professor at New Orleans' Tulane University, told a forum on torture this week. And when governments, military organisations and police services refuse to label "tough interrogation" as torture, it creates an atmosphere where the mistreatment of prisoners is allowed to flourish. After studying Brazilian police from 1964 to 1985, Ms Huggins laid out the classic conditions for mistreatment of prisoners. As part of the American Association for the Advancement of Science's marking United Nations International Day in Support of Victims of Torture, she spoke to a Washington, DC, conference about them. The half-day forum also heard from physicians who treat people who have been tortured and the effects of torture and detention on the families of victims. The conference was staged less than two miles from the United States Supreme Court, where the justices were releasing a decision that said prisoners at Guantanamo Bay were entitled to challenge their custody through American courts. The issue of torture has dominated the news since photographs of prisoners at the US-controlled Abu Ghraib prison in Iraq came to light. (C)BBC

Keyword: Aggression
Link ID: 5749 - Posted: 07.03.2004

Every year, Independence Day brings a unique array of sights and an overload of sounds, with fireworks as the main culprit for both. But while most people are aware of the harm and damage a burning Roman candle can do if not handled properly, many aren't thinking about protecting their hearing on one of the noisiest days of the year. "It's quite possible for a person on the fourth of July to experience a dose of noise that's significant enough to cause hearing loss and ringing in their ears, due to an explosion very close to their ears possibly, or just a cumulative exposure over the day," says Robert Novak, professor of audiology and clinical director for the department of Audiology and Speech Sciences at Purdue University. David Sorensen, a Philadelphia attorney, can vouch for that. Every July 4th he's reminded of the summer he let freedom ring a little too loudly: "The summer after fourth grade, right around July 4th when there were a lot of fireworks in the neighborhood," Sorensen recalls. "I liked caps. And one day I smashed more than just a few at a time and I had a loud ringing in my ears." More than three decades later, that ringing still hasn't stopped, and has made everyday living difficult. "My goal is to have a quiet night's sleep," says Sorensen. © ScienCentral, 2000- 2004.

Keyword: Hearing
Link ID: 5748 - Posted: 06.24.2010

Anesthetics are slowly giving up the secrets of how they work John Travis Take a stroll through the Boston Public Garden, the nation's oldest botanical garden, and you'll find an array of plaques, monuments, and memorials honoring famous people of history. Not far from a statue of George Washington on horseback, there's a tall monument that honors not a person, but a chemical. This tribute to ether is probably the world's only monument to a drug. A statue representing the Good Samaritan tops the structure, which displays the inscription, "There shall be no more pain." Erected in the 19th century, the tribute commemorates ether's first use as a surgical general anesthetic, which took place in 1846 at the Massachusetts General Hospital in Boston. Today, it's hard to imagine what surgery was like before this discovery and the subsequent development of inhaled and injected chemicals that are even more effective in rendering people unconscious and insensitive to pain. General anesthesia has a "magical quality to it," says anesthesiologist James Sonner of the University of California, San Francisco. "It was and still is amazing that you can . . . make an organism comatose, unresponsive enough to perform surgery, and reverse the whole thing." Copyright ©2004 Science Service

Keyword: Pain & Touch
Link ID: 5747 - Posted: 06.24.2010

People who have early stage Alzheimer's disease (AD) could be more capable of learning than previously thought, according to two new studies supported by the National Institute on Aging (NIA), a part of the National Institutes of Health. The promising studies suggest that some people with early cognitive impairment can still be taught to recall important information and to better perform daily tasks. In a July 2004 report, researchers in Miami, FL, found mildly impaired AD patients who participated in 3-to-4 months of cognitive rehabilitation had a 170 percent improvement, on average, in their ability to recall faces and names and a 71 percent improvement in their ability to provide proper change for a purchase. The participants also could respond to and process information more rapidly and were better oriented to time and place compared to a similar group of AD patients who did not receive this targeted intervention. These improvements were still evident 3 months after the cognitive training ended. The findings, by David A. Loewenstein, Ph.D., and colleagues at the University of Miami School of Medicine and Mount Sinai Medical Center, Miami Beach, are reported in the July-August 2004 issue of the American Journal of Geriatric Psychiatry. The Loewenstein report follows a recent study by researchers at Washington University in St. Louis who found that older people with early-stage AD retained functioning levels of implicit memory similar to young adults and older adults who did not have AD. Implicit memory is relatively unconscious and automatic: Information from the past "pops into mind" without a deliberate effort to remember. This unconscious, implicit memory is important for common skills and activities, such as speaking a language or riding a bicycle.

Keyword: Alzheimers; Learning & Memory
Link ID: 5746 - Posted: 07.03.2004

Scientists have shown how the brain can be fooled into feeling sensations in a fake limb. They recorded changes in brain activity during an experiment in which volunteers were made to think a rubber hand was their own limb. The University College London team hope their work will shed light on self-perception disorders such as schizophrenia and stroke. Their work is published in Science Express Online. In the study, funded by the Wellcome Trust, volunteers hid their right hand under a table and a rubber hand was put in front of them at an angle to make it look like part of their body. The rubber hand and hidden real hand were stroked simultaneously with a paintbrush while the volunteer's brain was scanned using magnetic resonance imaging. It took just 11 seconds for volunteers to start feeling the rubber hand was their own. The stronger the feeling, the greater the activity recorded in the brain. Volunteers were later asked to point towards their right hand. Most pointed towards the rubber hand instead of the real one, showing how the brain had readjusted. The researchers found one area of the brain, called the premotor cortex, recognises the body by accepting information from three different senses - vision, touch and proprioception (position sense).

Keyword: Pain & Touch
Link ID: 5745 - Posted: 07.02.2004

As the evidence accumulates for epigenetics, researchers reacquire a taste for Lamarckism By Leslie A. Pray Toward the end of World War II, a German-imposed food embargo in western Holland--a densely populated area already suffering from scarce food supplies, ruined agricultural lands, and the onset of an unusually harsh winter--led to the death by starvation of some 30,000 people. Detailed birth records collected during that so-called Dutch Hunger Winter have provided scientists with useful data for analyzing the long-term health effects of prenatal exposure to famine. Not only have researchers linked such exposure to a range of developmental and adult disorders, including low birth weight, diabetes, obesity, coronary heart disease, breast and other cancers, but at least one group has also associated exposure with the birth of smaller-than-normal grandchildren.1 The finding is remarkable because it suggests that a pregnant mother's diet can affect her health in such a way that not only her children but her grandchildren (and possibly great-grandchildren, etc.) inherit the same health problems. In another study, unrelated to the Hunger Winter, researchers correlated grandparents' prepubertal access to food with diabetes and heart disease.2 In other words, you are what your grandmother ate. But, wait, wouldn't that imply what every good biologist knows is practically scientific heresy: the Lamarckian inheritance of acquired characteristics? If agouti mice are any indication, the answer could be yes. The multicolored rodents make for a fascinating epigenetics story, which Randy Jirtle and Robert Waterland of Duke University told last summer in a Molecular and Cell Biology paper; many of the scientists interviewed for this article still laud and refer to that paper as one of the most exciting recent findings in the field. The Duke researchers showed that diet can dramatically alter heritable phenotypic change in agouti mice, not by changing DNA sequence but by changing the DNA methylation pattern of the mouse genome.3 "This is going to be just massive," Jirtle says, "because this is where environment interfaces with genomics." © 2004, The Scientist LLC, All rights reserved.

Keyword: Genes & Behavior; Development of the Brain
Link ID: 5744 - Posted: 06.24.2010

The Saharan desert ant (Cataglyphis fortis) takes no chances when it comes to homeland security. It viciously attacks ants from other colonies that get too close to its nest. Now researchers have found that the ant relies on the same internal navigation system it uses for foraging to decide whether an intruder has come too close for comfort. Many animals fly into a defensive rage when they sense competitors edging in on their territory. But in the sandy Sahara, few environmental cues mark territorial boundaries. Behavioral neurobiologists Markus Knaden and Rüdiger Wehner of the University of Zürich in Switzerland wondered whether the sight or smell of the nest primes the ants for a fight or if their internal navigation system puts them on alert. Previous research showed that the desert ants somehow keep track of every step and turn they take when out foraging for food and integrate that information to plot a straight line back home. The system apparently serves the ants well, enabling them to find their way in an environment devoid of landmarks and get back to the nest before shriveling up in the hot sun. To test whether the ants' navigation system also plays a role in aggression, Knaden and Wehner placed a feeder 20 meters from a desert ant nest. Left undisturbed, the ants snatched a bite of food and ran straight back to their nest. But the researchers grabbed the ants as soon as the ants picked up a piece of food and moved them to a 40-meter-square grid 2 kilometers away. There, they turned the ants loose and let them run either 20 meters or only 5 meters before testing their willingness to fight other ants. The ants that ran the whole 20 meters--covering what would have been the distance back to their nest--were far more aggressive than the ones that only ran 5, the team reports in the 2 July issue of Science.

Keyword: Aggression
Link ID: 5743 - Posted: 07.02.2004

ITHACA, N.Y. -- A laser-based microscopy technique may have settled a long-standing debate among neuroscientists about how brain cells process energy -- while explaining what's really happening in PET (positron emission tomography) imaging and offering a better way to observe the damage that strokes and neurodegenerative diseases, such as Alzheimer's, wreak on brain cells. Multi-photon microscopy scans by Cornell University biophysicists of living brain tissue, as reported in the latest issue of Science (July 2, 2004), reveal exactly how and when neurons (the cells that do the thinking) and astrocytes (the starburst-shaped glial cells that service neurons) interact to burn oxygen and glucose, after astrocytes make lactate from glucose in the bloodstream, to meet the extraordinary energy demands of the brain. Based on imaging of two different energy states of NADH (nicotinamide adenine dinucleotide, a coenzyme involved in brain-cell metabolism), the Cornell biophysicists say they have both confirmed and redefined the controversial "astrocyte-neuron lactate shuttle" hypothesis for brain energy metabolism. "Over the past decade scientists have passionately debated whether the activated brain burns glucose completely to water or incompletely to lactate," said Karl A. Kasischke, M.D., lead author of the Science paper titled "Neural Activity Triggers Neuronal Oxidative Metabolism Followed by Astrocytic Glycolysis."

Keyword: Glia
Link ID: 5742 - Posted: 07.02.2004

The remnants of a remarkably petite skull belonging to one of the first human ancestors to walk on two legs have revealed the great physical diversity among these prehistoric populations. But whether the species Homo erectus, meaning "upright man", should be reclassified into several distinct species remains controversial. Richard Potts, from the National Museum of Natural History at the Smithsonian Institute in Washington, DC, and colleagues discovered numerous pieces of a single skull in the Olorgesailie valley, in southern Kenya, between June and August 2003. The bones found suggest the skull is that of a young adult Homo erectus who inhabited the lush mountainside some 930,000 years ago. The prominent brow and temporal bone resemble other Homo erectus specimens found elsewhere in Africa, and in Europe, Indonesia and China. But the skull itself is around 30% smaller, which is likely to have corresponded to a similar difference in body size. The specimen helps fill a gap in the fossil record as very few Homo erectus specimens of this age have been found in Africa so far. © Copyright Reed Business Information Ltd.

Keyword: Evolution
Link ID: 5741 - Posted: 06.24.2010

Scientists have made the first recordings of the human brain's awareness of its own body, using the illusion of a strategically-placed rubber hand to trick the brain. Their findings shed light on disorders of self-perception such as schizophrenia, stroke and phantom limb syndrome, where sufferers may no longer recognize their own limbs or may experience pain from missing ones. In the study published today in Science Express online, University College London's (UCL) Dr Henrik Ehrsson, working with Oxford University psychologists, manipulated volunteers' perceptions of their own body via three different senses - vision, touch and proprioception (position sense). They found that one area of the brain, the premotor cortex, integrates information from these different senses to recognize the body. However, because vision tends to dominate, if information from the senses is inconsistent, the brain "believes" the visual information over the proprioceptive. Thus, someone immersed in an illusion would feel, for example, that a fake limb was part of their own body. In the study, each volunteer hid their right hand beneath a table while a rubber hand was placed in front of them at an angle suggesting the fake hand was part of their body. Both the rubber hand and hidden hand were simultaneously stroked with a paintbrush while the volunteer's brain was scanned using functional magnetic resonance imaging.

Keyword: Pain & Touch
Link ID: 5740 - Posted: 07.02.2004