Andreas von Bubnoff The inflamed mammary glands of sheep have been found to contain protein particles that cause scrapie, a sickness similar to mad cow disease. This suggests that the suspect proteins, called prions, may also be present in the milk of infected animals. If prions exist in the milk of cows infected with both an inflammatory illness and mad cow disease, formally known as bovine spongiform encephalopathy (BSE), this raises concerns for human health. Consumption of prion-contaminated meat from cows with BSE is believed to cause the fatal variant Creutzfeldt-Jakob disease (vCJD) in people; so might contaminated milk. Adriano Aguzzi, the lead researcher on the study, has not detected prions in milk itself, because it is difficult to analyse for the abnormal proteins. But he says he expects to find them. "It is unlikely that the prions are not in the milk," says Aguzzi, a pathologist at the University of Zurich Hospital, Switzerland. "And the prospect is not a pleasant one." ©2005 Nature Publishing Group

Keyword: Prions
Link ID: 8108 - Posted: 06.24.2010

A new pathway for treating multiple sclerosis may have been found, if “exciting” results in mice can be replicated in humans. MS is an incurable degenerative disease caused by the body’s immune system attacking the protective myelin sheath encasing the nerves that make up the central nervous system. The nerve fibres become increasingly damaged by scar tissue, known as sclerosis, which leads to paralysis and loss of speech and vision. But researchers trying a novel therapy on a mouse version of MS report that the mice showed “almost no inflammation of the myelin sheath and no nerve damage”. Furthermore, MS is characterised by periods of remission and relapse, but the mice recovered with fewer and far less severe relapses. The therapy targets immune system cells called T-cells. These malfunction in MS patients, producing inflammatory molecules that destroy the myelin sheath. The new treatment, which uses a class of molecules called kynurenines, works by inhibiting the T-cells’ production of inflammatory molecules and prompting them to produce agents that “mop up” the molecules. © Copyright Reed Business Information Ltd.

Keyword: Multiple Sclerosis
Link ID: 8107 - Posted: 06.24.2010

Howard Hughes Medical Institute (HHMI) researchers have deciphered a key part of the regulatory code that governs how motor neurons in the spinal cord connect to specific target muscles in the limbs. The researchers said that understanding this code may help guide progress in restoring motor neuron function in people whose spinal cords have been damaged by trauma or disease. The studies suggest that the code — which involves members of the family of transcription factors encoded by the Hox genes — could also govern the establishment of other spinal cord circuits. This circuitry includes interneurons that control motor neuron firing patterns and sensory neurons that transmit feedback information on muscle action. The research team, which was led by HHMI investigator Thomas M. Jessell, published its findings in the November 4, 2005, issue of the journal Cell. Jessell collaborated on the studies with HHMI research associate Jeremy S. Dasen, Bonnie C. Tice and Susan Brenner-Morton, all of whom are at Columbia University. The work was also funded by grants from the National Institute of Neurological Disorders and Stroke and Project ALS. According to Jessell, members of the Hox gene family had been known to regulate aspects of brain development, but “few people had paid attention to the fact that these genes are also expressed in the spinal cord.” Earlier work performed by Dasen and Jessell, in collaboration with Jeh-Ping Liu, who is now at the University of Virginia, established that certain Hox proteins control the differentiation of motor neurons into columns in the spinal cord. These columns, which are arrayed along the anterior-posterior length of the spinal cord, form in the initial phases of motor neuron organization. That organization determines whether motor neurons grow to the limbs or to other targets. © 2005 Howard Hughes Medical Institute.

Keyword: Development of the Brain
Link ID: 8106 - Posted: 06.24.2010

Women with high levels of the sex hormone oestrogen have prettier faces, research suggests. The findings make evolutionary sense - men are attracted to the most fertile women, the University of St Andrews team told a Royal Society journal. Oestrogen levels during puberty can impact on appearance by affecting bone growth and skin texture, they said. But make-up masks this effect, allowing less attractive women to compensate for their lack of natural mating cues. The team of psychologists at the University's Perception Lab photographed 59 young women's faces aged between 18 and 25 and analysed their sex hormone levels. They then asked 30 volunteers - 15 male and 15 female - to rate the faces according to attractiveness. Both male and female volunteers rated the faces of the women with the highest hormone levels as the most attractive. These faces tended to have classically feminine features, such as larger eyes and lips and smaller noses and jaws. However, when the women in the photographs were wearing make-up, no relationship between attractiveness and oestrogen was found. The researchers believe that, while make-up improves facial appearance, it may be masking cues normally seen in the face. Head of the study, Miriam Law Smith, said: "Women are effectively advertising their general fertility with their faces. (C)BBC

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 8105 - Posted: 11.03.2005

Scientists have found that the tongue has taste receptors for fat, which might explain why we like fried foods. Conventionally, experts have thought that the tongue detects five tastes - sweet, salty, sour, bitter and umami taste for protein rich foods. But tests on rodents showed a receptor on the tongue tastes fat - it is not known if it is the same for humans. The work by French researchers from the University of Burgundy appears in the Journal of Clinical Investigation. Investigator Philippe Besnard and his team believe the CD36 receptors that they found were important for evolutionary reasons - to ensure animals ate a high energy diet when foods were scarce. But in the current Western climate, where food is in abundance and about 40% of the energy we consume comes from fat, this may be a disadvantage for the waistline if the same receptor is present in humans. The CD36 receptor is already known to exist in many tissues involved in fat storage. To see whether the receptor might be the tongue's fat detector, the researchers studied rats and mice that were normal or had the gene for CD36 "knocked out" so that the receptor no longer worked. The normal rodents showed a preference for fatty foods when offered them, yet the knock out mice did not. Also, when the researchers put a fatty liquid onto the tongues of the normal rats, this triggered a release of fat-processing substances from the digestive organs. This reaction did not happen in the knock out mice. (C)BBC

Keyword: Chemical Senses (Smell & Taste); Obesity
Link ID: 8104 - Posted: 11.03.2005

AUSTIN, Texas--Neurons experience large-scale changes across their dendrites during learning, say neuroscientists at The University of Texas at Austin in a new study that highlights the important role that these cell regions may play in the processes of learning and memory. The research, published online Oct. 23 and in the November issue of the journal Nature Neuroscience, shows that ion channels distributed in the dendritic membrane change during a simulated learning task and that this requires the rapid production of new proteins. "Our new work strongly supports the idea that learning involves changes in dendrites," says Dr. Daniel Johnston, director of the Center for Learning and Memory and professor in the Institute for Neuroscience. The finding could also lead to advances in understanding conditions like epilepsy and age-related memory loss and could point to potential treatment opportunities for such conditions in the future. Dendrites--the thin branch-like extensions of a neuron cell--receive many inputs from other neurons that transmit information through contact points called synapses. Much attention has been focused on the role that changes at synapses play in learning. They change in ways that make it easier for connected neurons to pass information.

Keyword: Learning & Memory
Link ID: 8103 - Posted: 11.03.2005

Symptoms, like difficultly sounding out words, make dyslexia readily detectable. But the causes of the disability are still hard to pinpoint. "Why? What causes these otherwise very bright children to struggle to read?" asks pediatrician Sally Shaywitz, co-director of Yale University's Center for the Study of Learning and Attention, and the author of "Overcoming Dyslexia." "Dyslexia is an unexpected difficulty first in learning to read, and then in having to struggle to read," she explains. "That means the person who is dyslexic has all the factors present that say, 'This person should be a good reader. They're intelligent, they're motivated, and they've had good education. Yet they still struggle to read." If left untreated, childhood dyslexia becomes an adult problem. "It's not something that's outgrown," says neurophysiologist Lynn Flowers from Wake Forest University Baptist Medical Center. "Ten percent of the child and therefore the adult population is affected by dyslexia to some degree," she says. "It isn't an all or nothing kind of disorder, it comes in shades as well." © ScienCentral, 2000-2005.

Keyword: Dyslexia
Link ID: 8102 - Posted: 06.24.2010

As any chef at a greasy spoon can attest, humans have a taste for fatty foods. Now, scientists may know why. Researchers have found a new receptor on mice and rat tongues that detects fat and helps prepare the body to digest it. The results may help explain why some people crave fat more than others and could help researchers uncover new ways to fight obesity. It's long been clear that humans and rodents taste sweet, sour, bitter, salty, and protein-rich foods, but researchers thought we sensed the fat in food by its smell and creamy texture. Over the past decade or so, however, results have dribbled in suggesting we--or at least mice and rats--taste fats. In one study, applying a chemical to the tongue that blocks a fat-digesting enzyme prevented rats and mice from tasting fats and fatty acids, a breakdown product of fats. Intrigued, physiologist Philippe Besnard of the University of Bourgogne in Dijon, France, and colleagues focused on a fatty-acid receptor called CD36 that's found in fat and other tissues. After chemically linking a red fluorescent dye to antibodies that bound CD36, the researchers showed that taste buds glowed red, indicating that CD36 was in the right place to do the job. To see if animals use CD36 to taste fats, the team bred a line of mice that lacked the receptor. When given a choice between their standard fare and fat-enriched treats, normal mice consumed 3 times as much of the junk food, but mutant mice showed no preference, presumably because they couldn't taste the difference. © 2005 by the American Association for the Advancement of Science.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 8101 - Posted: 06.24.2010

By Jennifer Viegas, Discovery News — As women experience their regular menstrual cycle, they undergo bodily changes that can cause emotional mood swings, but scientists have just discovered that women without problems associated with PMS have brains that can regulate the cyclical emotional overloads. The study, published in a recent Proceedings of the National Academy of Sciences, represents the first time that PMS (Premenstrual Syndrome) has been studied using functional MRI brain scanning, along with tests designed to probe emotional changes. The findings suggest that PMS and more serious symptoms associated with menstruation are driven by forces that may be beyond a woman's control. "In the past, many women suffering from PMS were told to, 'Just get over it,' or were asked, 'Why can't you handle this?'" said David Silbersweig, one of the study's authors. Silbersweig, a physician and researcher at Cornell University's Weill Medical College, added, "We now hope that our research will help the public to understand that PMS can involve changes in the brain, and that the condition is not just psychological, but that biological systems are involved that help to control emotions and behavior." © 2005 Discovery Communications Inc.

Keyword: Hormones & Behavior; Emotions
Link ID: 8100 - Posted: 06.24.2010

By Beth Baker Special to The Washington Post In 2001, Ellen Proxmire faced a tough decision regarding her husband -- William Proxmire, the former Democratic senator. Diagnosed seven years earlier with Alzheimer's disease, he frequently wandered from home. He even managed to escape from a locked hospital unit. When he represented Wisconsin from 1957 to 1989, Proxmire had a reputation as a maverick. But the independent streak prized in a politician was dangerous in a person living with Alzheimer's disease. One day he eluded the caregiver hired to keep an eye on him at the Library of Congress, where he still enjoyed a private carrel. Hours later he was found walking on the Southeast Freeway. Someone recognized him and picked him up and brought him home, his wife said. Much as she hated to admit it, Ellen Proxmire knew she could no longer care for her husband at home. She visited some 20 Alzheimer's residential facilities in the Washington area and in Arizona, where she hoped to live. Even those with good reputations she found dismal. "People were drugged and sitting in a corner, tied to chairs," she said. "And there are some places who don't want someone who is difficult." © 2005 The Washington Post Company

Keyword: Alzheimers
Link ID: 8099 - Posted: 06.24.2010

HOUSTON --- Visual information can be processed unconsciously when the area of the brain that records what the eye sees is temporarily shut down, according to research at Rice University in Houston. The research, published the week of Oct. 31 in the Proceedings of the National Academy of Sciences' (PNAS) online Early Edition, suggests the brain has more than one pathway along which visual information can be sent. For the study, the researchers induced temporary, reversible blindness lasting only a fraction of a second in nine volunteers with normal vision. Transcranial magnetic stimulation (TMS), a harmless noninvasive technique using brief magnetic pulses, was applied to the volunteers' visual cortex -- the area at the back of the brain that processes what the eye sees - to interrupt the normal visual pathway. The volunteers looked at a computer screen, and during their momentary blindness, either a horizontal or a vertical line or a red or a green dot flashed on the screen. Researchers then asked the study participants whether they had seen a horizontal or a vertical line; because their primary visual pathway had been shut down, the participants reported that they saw nothing. However, when forced to guess which line had appeared on their computer screen, the participants gave the correct answer 75 percent of the time. When the participants had to guess whether a red or a green dot had flashed on the screen, they gave the correct answer with 81 percent accuracy.

Keyword: Vision
Link ID: 8098 - Posted: 11.01.2005

By Jason Feifer From across the apartment, my girlfriend smelled smoke. "Is something burning?" she called to me in the kitchen. No, everything's fine, I yelled back. A few minutes later, she came in to investigate. She found me washing dishes, oblivious to the smoking George Foreman grill beside me. "You're so dying in a fire," she said as she yanked the plug from the wall. I don't know why I didn't see the smoke, but there was good reason I didn't smell it. Like an estimated 14 million Americans, I suffer from smell loss. Like a smaller number of them, I can't taste, either. I can occasionally appreciate a flower's aroma or food's flavor, but only vaguely and superficially. My imagination helps fill in the blanks; but when I'm blindfolded, I confuse mint ice cream and peanut butter ice cream. My girlfriend, who has the olfactory capabilities of a bloodhound, has run me through this test numerous times. She, like most everyone else I tell about this, simply cannot understand my experience. I have a hard time explaining it myself. It's as if my tongue and nose can sense differences -- water tastes different from juice, say, and unscented air smells different from perfume -- but the differences are faint and forgettable, and I have no ability to identify them. Chocolate is strawberry is scrambled eggs. © 2005 The Washington Post Company

Keyword: Chemical Senses (Smell & Taste)
Link ID: 8097 - Posted: 06.24.2010

By ERIC NAGOURNEY Botox may do more than just get rid of wrinkles. In addition to providing relief from eye spasms and migraines, Botox, formally botulinum toxin A, has now been found useful in treating the intense facial pain called trigeminal neuralgia. In a study published in the Oct. 25 issue of Neurology, the drug provided partial or complete relief to all 13 patients tested. Until now, anticonvulsant drugs or neurosurgery have been the only treatments for the disorder. The drugs can have unpleasant side effects, and the surgery is expensive and carries risks. Neither treatment is universally effective. Dr. Stephen D. Silberstein, a co-author on the paper, said he would recommend Botox even though it had not been randomly tested in controlled clinical trials. "The purists would say you shouldn't do something not proven in a double-blind study," Dr. Silberstein said, referring to research in which one group is given the medicine and another group is given a placebo. "But the surgical alternatives are unproven procedures that are more expensive and more risky. I don't see any reason not to use it just because we don't have all the evidence in." The Botox treatment requires injections of 10 units four or five times a year. Botox costs about $5 a unit, according to Dr. Silberstein, who is a professor of neurology at Jefferson Medical College in Philadelphia. Copyright 2005 The New York Times Company

Keyword: Pain & Touch
Link ID: 8096 - Posted: 11.01.2005

Looking in a mirror at a reflection of their healthy hand could help people with persistent pain ease their symptoms and eventually overcome their problem, say scientists in the latest edition of the journal Clinical Medicine. The treatment, being developed by researchers from the University of Bath and the Royal National Hospital for Rheumatic Diseases (RNHRD), is based on a new theory about how people experience pain even when doctors can find no direct cause. This ‘cortical’ model of pain suggests that the brain’s image of the body can become faulty, resulting in a mismatch between the brain’s movement control systems and its sensory systems, causing a person to experience pain when they move a particular hand, foot or limb. Researchers believe that this kind of problem could be behind a host of pain-related disorders, such as complex regional pain syndrome and repetitive strain injury. In an investigation of whether this system can be corrected using mirrors to trick the brain, researchers asked a number of patients with complex regional pain syndrome (a chronic debilitating condition affecting 10,000 – 20,000 patients in the UK at any one time) to carry out routine exercises in front of a mirror. University of Bath © 2004

Keyword: Pain & Touch
Link ID: 8095 - Posted: 06.24.2010

Genetic variations that cause miscues in brain development may play an important role in dyslexia, according to new research presented last week at a meeting of the American Society of Human Genetics in Salt Lake City. People with dyslexia have reading impairments despite normal intelligence. The problem affects between 5% and 17% of the population. In the last few years, geneticists have begun to point the finger at particular genes (ScienceNOW, 22 February). However, little is known about how these genes might contribute to the condition. In one new study, a collaboration of 20 researchers led by Haiying Meng and Jeffrey Gruen of Yale University School of Medicine homed in on a region of chromosome 6 that has been implicated in previous dyslexia studies. Using DNA collected from 536 people with a dyslexic in their families, the researchers tracked 147 single-nucleotide polymorphisms (SNPs), places where the genetic code differs by one letter in different people. Searching for SNPs that tend to have one "spelling" in people with reading impairments and another spelling in normal readers, the researchers found that a disproportionate number of such SNPs showed up in a gene called DCDC2. © 2005 by the American Association for the Advancement of Science.

Keyword: Dyslexia; Genes & Behavior
Link ID: 8094 - Posted: 06.24.2010

Liars could be caught out by the reaction of their stomachs to telling untruths, suggests preliminary research from the University of Texas, US. The team believe that the early-stage technique could one day improve the accuracy of polygraph tests, which rely mostly on monitoring heart activity. “The heart is unreliable because it’s affected by not only by your brain, but by many other factors, such as hormones,” says Pankaj Pasricha, who is leading the team. “The gut has a mind of its own – literally. It has its own well-developed nervous system that acts independently of almost everything except your unconscious brain.” The test uses a device called an electrogastrogram (EGG) to determine when a person’s stomach “beats” speed up from the typical three per minute. Whereas heart beats can increase whether a person is lying or telling the truth, the group’s initial findings from 16 test subjects reveal that the stomach’s rate typically does not increase if a person is telling the truth, however nervous they may be. “This might very well be the case,” says Kevin Murphy, a psychologist at Penn State University, Pennsylvania, US, who recently headed a panel for the US National Academy of Sciences to analyse the science behind polygraph devices. “But polygraph detectors, whatever their ilk, measure stress and not lying. This new test might give more, potentially very useful, data. But it won’t give you the definitive truth.” © Copyright Reed Business Information Ltd.

Keyword: Stress
Link ID: 8093 - Posted: 06.24.2010

Roxanne Khamsi Mickey Mouse may have kept quiet during his early days on the silver screen, but his lab counterparts seem to have a penchant for song. That's the finding in an analysis of the ultrasonic sounds made by male mice wooing potential mates. For years, animal-behaviour experts have known that mice make vocalizations that are too high in pitch to be picked up by the human ear. Young mice, for example, make 'isolation calls' when cold or distressed. And male mice emit ultrasonic sounds in the presence of a potential mate or in response to chemical sex cues, called pheromones, in the urine of female mice. But until now, scientists had not examined these sounds for musical patterns. Thanks in part to a sophisticated computer program, Timothy Holy and Zhongsheng Guo of the Washington University School of Medicine in St Louis, Missouri, were able to tackle this challenge. Holy began by writing software that shifts the pitch of the male mouse's sounds, making the sounds deeper so that they can be heard by humans. "No one had ever pitch-shifted the mouse vocalization," he says. "The first time I played it back it was pretty surprising: it sounded so much like birdsong." ©2005 Nature Publishing Group

Keyword: Sexual Behavior; Language
Link ID: 8092 - Posted: 06.24.2010

Vulnerability to anxiety may be down to the size of a brain structure involved in fearful memories, say US scientists. People with a thicker ventromedial prefrontal cortex were better able to cope with stressful experiences. The findings may help explain why some people develop post-traumatic stress disorder (PTSD) while others bounce back after adversity, say the authors. The Massachusetts General Hospital study appears in Proceedings of the National Academy of Science. While it is normal to experience physical and psychological symptoms after an extremely stressful event, such as the recent London terrorist attacks, some people will continue to be consumed by overwhelming fear and may develop PTSD. A person with PTSD may experience unwanted flashbacks, poor sleep and depression, and avoidance certain situations that could trigger memories of the event. Studies in animals suggest that the ventromedial prefrontal cortex (vmPFC) is involved with helping the brain forget fearful events. Also, studies of have shown that people with PTSD have unusually inactive vmPFCs, again suggesting that this brain region is important in anxiety. In the current study, Dr Mohammed Milad and colleagues scanned the brains of 14 volunteers. (C)BBC

Keyword: Stress
Link ID: 8091 - Posted: 10.31.2005

By Shankar Vedantam, Washington Post Staff Writer For centuries, poets, philosophers and scientists have debated why humans spend as much as a third of their lives asleep. For Shakespeare, sleep was the "balm of hurt minds" -- denied to murderers such as Macbeth. For Sigmund Freud, sleep provided a platform for dreams, an outlet for the psyche to work out complex and dangerous feelings. Scientists today believe sleep consolidates learning and memory, and supports many essential mental and physical functions. The theorists have long disagreed about one another's ideas, but most agree on one thing: If nature makes people sleep away so much of their lives, the reason has to be something crucial. That seemed to be the only way to explain why sleep-deprived people crave sleep so badly that they doze off behind the wheel of a car going 60 mph, and why rats deprived of sleep die sooner than rats deprived of food. Yet a wealth of sleep research has regularly produced baffling paradoxes and conflicting lines of evidence about the uses, role and need for sleep. If sleep is primarily about providing mental rest, why do people's brains remain so active during sleep, as research in recent decades has found? © Copyright 1996-2005 The Washington Post Company

Keyword: Sleep; Evolution
Link ID: 8090 - Posted: 06.24.2010

By PAUL COLLINS The moment I opened my eyes I knew something was wrong. The sun wasn't up yet, and a cry was forming in Morgan's throat. I padded over to his bed, puzzled. His darkened room was filled with battered brass instruments, playing cards, thick reference books - the inscrutable fascinations of an autistic 5-year-old. Morgan had always been in his own world, but it was a fairly happy one. In his waking hours he'd hum "In the Hall of the Mountain King" while shuffling through mysterious sequences of pinochle cards; lately he had become engrossed in an illustrated encyclopedia of electric guitars, squinting and smiling at the old pictures and names: Danelectro, Rickenbacker, Gretsch. Sometimes he'd brush past his baby brother and march up to me with a lump of Play-Doh. "Gibson ES-350," he'd demand. As I'd gamely fashion a fretboard and tuners out of clay, he'd grab his tarnished French horn, skip outside to the tree swing and blast out wobbling notes at the neighbors: borp, brap, boorp. I leaned farther over his bed. "Morgan?" Bam. I staggered back, smacking away another punch, yelling in surprise, "Go to your room!" - which didn't mean much since he was already in it. I retreated across the hall and snapped on the bathroom light. Blood was flowing from my nose. Behind me Morgan thrashed on his bed, pounding and kicking the bedroom wall, screaming. Copyright 2005 The New York Times Company

Keyword: Autism; Depression
Link ID: 8089 - Posted: 10.31.2005