By Constance Holden Brain scans have shown that speakers of English and Chinese process language somewhat differently. Now a new study has extended this finding, showing that English and Chinese speakers also process numbers differently--even though they use the same Arabic symbols. The authors believe it is not just language but mode of language learning that makes the difference. When reading, Chinese speakers tend to rely on visual-spatial brain areas, while English speakers rely more on language-related brain areas. To see whether the same applied to number processing, a U.S.-Chinese research team led by Yiyuan Tang of Dalian University of Technology in China compared 12 native English speakers living in Dalian with 12 local university students. The subjects, all in their 20s, were equally divided by sex, and their brains were scanned while they performed simple tasks. One involved looking at three meaningless symbols and judging the spatial orientation of the third in relation to the first two. This task, which activated both visual and language pathways, elicited no differences between the two language groups. But when this task was repeated with numbers rather than symbols, "remarkable differences" emerged, the authors report online this week in Proceedings of the National Academy of Sciences. © 2006 American Association for the Advancement of Science.

Keyword: Language
Link ID: 9066 - Posted: 06.24.2010

Andy Coghlan The precise part of the brain likely to be the seat of heterosexual desire in women has been revealed by experiments on mice. The study confirms that the hormone oestrogen is vital for arousal, but only in the specific area of the brain called the ventromedial nucleus (VMN) in the hypothalamus. Sonoko Ogawa of the University of Tsukuba in Japan and her collaborators in the US discovered this by blocking the effects of oestrogen exclusively in that part of the brain in mice. They did this with tiny slugs of genetic material called small hairpin RNAs designed to block production of oestrogen receptor alpha, the molecule where oestrogen docks on cells in the VMN and elsewhere in the body. They used a harmless virus to shuttle the RNAs exclusively into the VMN, so that oestrogen signals would only be blocked there and nowhere else in the body. The effect was dramatic - the females refused to have sex. “They became extremely aggressive towards males, and started biting and kicking when males approached,” says Ogawa. The females refused to mate and none of them showed the usual signs of sexual receptivity. By contrast, control females injected with neutral RNAs mated as usual. View a video of the normal mice (top) and those in which sexual receptivity was blocked (bottom). © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 9065 - Posted: 06.24.2010

Over 80% of people with Parkinson's disease frequently experience depression, a European survey finds. But the poll of 500 patients with mild-to-moderate forms of the disease found 40% rarely - or never - talked to their doctors about depression. And two thirds of doctors polled said they considered other symptoms were more important than depression. But Parkinson's experts said depressive symptoms were as important as motor problems for people with the disease. Around one in 500 people in the UK have Parkinson's disease. Around 10,000 new cases are diagnosed annually, with one in 20 affected someone under 40. The most well-known symptom is tremors in the arms and legs. But depression can stem from people's feelings about their condition, or as another symptom caused by the neurological effects of the disease. This survey covered patients in France, Germany, Italy, Spain and the UK. Researchers also spoke to 500 specialist doctors in the same countries. Virtually all said the majority of their patients "often" or "sometimes" experienced symptoms of depression. But 49% said such symptoms were difficult to recognise. Doctors said the main reason they did not discuss depression was that they felt that patients did not rate these symptoms as being as important as other aspects of their condition. But patients said depression was almost as significant for them as movement problems. (C)BBC

Keyword: Parkinsons; Depression
Link ID: 9064 - Posted: 06.26.2006

By BENOIT DENIZET-LEWIS Last month, the Picower Institute for Learning and Memory at the Massachusetts Institute of Technology was host to a conference about addiction for a small, invitation-only crowd of neuroscientists, clinicians and public policy makers. It was an unusual gathering. Addiction conferences are usually sober affairs, but M.I.T. offered a lavish cocktail reception (with an open bar, no less). More important, the conference was a celebration of the new ways scientists and addiction researchers are conceptualizing, and seeking to treat, addiction. While many in the treatment field have long called addiction a "disease," they've used the word in vague and metaphorical ways, meaning everything from a disease of the mind to a disease of the spirit. Many assumed that an addict suffers from a brain-chemistry problem, but scientists had not been able to peer into our heads to begin to prove it. Discuss medical approaches to treating addiction. Now they can, using advances in brain-imaging technology. And they tend to agree on what they see, although not necessarily on how to fix it: addiction — whether to alcohol, to drugs or even to behaviors like gambling — appears to be a complicated disorder affecting brain processes responsible for motivation, decision making, pleasure seeking, inhibitory control and the way we learn and consolidate information and experiences. This new research, in turn, is fueling a vast effort by scientists and pharmaceutical companies to develop medications and vaccines to treat addiction. The National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism are studying, or financing studies on, more than 200 addiction medications. Copyright 2006 The New York Times Company

Keyword: Drug Abuse
Link ID: 9063 - Posted: 06.24.2010

People who have been exposed to pesticides are 70 percent more likely to develop Parkinson's disease than those who haven't, according to a new study. The results suggest that any pesticide exposure, whether occupationally related or not, will increase a person's risk of the disease. This means that using pesticides in the home or garden may have similarly harmful effects as working with the chemicals on a farm or as a pest controller. The research, published in the July issue of Annals of Neurology, provides the strongest evidence to date of the link between pesticide exposure and Parkinson's. The study included over 143,000 men and women who completed extensive lifestyle questionnaires beginning in 1982, and follow-up surveys through 2001. All subjects were symptom-free at the beginning of the project, when they were asked about their occupation and exposure to potentially hazardous materials. Since then, 413 of them have developed confirmed cases of Parkinson's, with a greater incidence of the disease in those who spent time around pesticides. "Low- dose pesticide exposure was associated with a significant increase in risk for Parkinson's disease," says lead author Alberto Ascherio of the Harvard School for Public Health. "I think this is one reason to be careful about using pesticides in general." Although the causes of Parkinson's are not well understood, it has long been suspected that environmental factors play a large role. Animal studies have shown that chemical compounds commonly used as pesticides can cause a degeneration of dopamine-producing neurons. © 1996-2006 Scientific American, Inc

Keyword: Parkinsons; Neurotoxins
Link ID: 9062 - Posted: 06.24.2010

Researchers at Yale School of Medicine have discovered in the placenta what may be the earliest marker for autism, possibly helping physicians diagnose the condition at birth, rather than the standard age of two or older. The findings are reported in the June 26 online issue of Biological Psychiatry. Autism is a developmental disorder that has a profound effect on socialization, communication, learning and other behaviors. In most cases, onset is early in infancy. Information on the earliest development aspects of autism in children has been limited even though approximately one in every 200 children is diagnosed with an Autism Spectrum Disorder (ASD). The earlier the diagnosis is made, the greater the treatment impact. Current studies are searching for characteristics in children at risk for ASD so that the diagnosis can be made prior to age one. The ideal time for diagnosis would be at birth, according to senior author on the study Harvey J. Kliman, M.D., research scientist in the Department of Obstetrics, Gynecology & Reproductive Sciences at the Yale School of Medicine. In previous work, Kliman had observed an unusual pathologic finding in the placentas from children with Asperger Syndrome, an ASD condition which, like autism, impairs the ability to relate to others. They found that the placentas from ASD children were three times more likely to have the inclusions. Kliman and the team identified trophoblast inclusions by performing microscopic examinations of placental tissues.

Keyword: Autism
Link ID: 9061 - Posted: 06.26.2006

MADISON-Although millions depend on medications such as Ritalin to quell symptoms of attention deficit hyperactivity disorder (ADHD), scientists have struggled to pinpoint how the drugs work in the brain. But new work at the University of Wisconsin-Madison is now starting to clear up some of the mystery. Writing in the journal Biological Psychiatry, UW-Madison researchers report that ADHD drugs primarily target the prefrontal cortex (PFC), a region of the brain that is associated with attention, decision-making and an individual's expression of personality. The finding could prove invaluable in the search for new ADHD treatments, and comes amidst deep public concern over the widespread abuse of existing ADHD medicines. "There's been a lot of concern over giving a potentially addictive drug to a child [with ADHD]," says lead author Craig Berridge, a UW-Madison professor of psychology. "But in order to come up with a better drug we must first know what the existing drugs do." A behavioral disorder that afflicts both children and adults, ADHD is marked by hyperactivity, impulsivity and an inability to concentrate. The National Institute of Mental Health estimates that 2 million children in the U.S. suffer from the condition, with between 30 to 70 percent of them continuing to exhibit symptoms in their adult years.

Keyword: ADHD
Link ID: 9060 - Posted: 06.26.2006

Helen Pearson Stimulating a protein on the surface of the brain's stem cells helps rats recover after a stroke, US researchers have found. The discovery suggests that in humans it could be possible to provoke the body's own stem cells into repairing an injury, rather than laboriously growing and transplanting new cells. Researchers believe that many of the body's tissues harbour stem cells capable of dividing to make new tissue. But some of these are recalcitrant and do not naturally divide to repair damage wreaked by severe injuries such as stroke or spinal-cord damage. Ronald McKay and his colleagues at the National Institute of Neurological Disorders and Stroke in Bethesda, Maryland, have now shown that one protein, called Notch, can boost the survival of three different types of stem cell1. Notch sits on cell surfaces and is vital for the correct growth of embryos. The team studied rats afflicted with a stroke-like brain injury that normally dulls their movement. When they infused the animals' brains for one week with a molecule that stimulates Notch, the animals' movements improved. The rats also sprouted a collection of new cells in the brain. ©2006 Nature Publishing Group

Keyword: Stroke; Regeneration
Link ID: 9059 - Posted: 06.24.2010

By NICHOLAS WADE Biologists say they have gained a new insight into the basic cause of Parkinson's disease that, if confirmed, could lead to a novel class of drugs. The cause of the disease appears to lie in the nerve cell's internal delivery system for shuttling packets of chemicals around, a team of researchers led by Susan Lindquist of the Whitehead Institute in Cambridge, Mass., report in today's issue of Science. Tremors and other symptoms of Parkinson's result from the death of certain neurons. Another sign of the disease is the appearance inside these neurons of clumps of protein known as Lewy bodies. Many experts believe the clumps are toxic to the neurons. But the reason for the clumps is obscure, as is the presence in them of large amounts of a mysterious protein known as alpha synuclein. Dr. Lindquist and her colleagues believe they have come close to defining the normal role of this protein. It appears to be involved in the elaborate system by which packets of chemicals are transferred between compartments within the cell, and may accumulate in human cells because of a breakdown in this rapid and tightly controlled traffic, she believes. She has also been able to reverse the damage, at least in laboratory organisms, by inserting genes that counteract synuclein. Copyright 2006 The New York Times Company

Keyword: Parkinsons
Link ID: 9058 - Posted: 06.24.2006

By Shankar Vedantam Americans are far more socially isolated today than they were two decades ago, and a sharply growing number of people say they have no one in whom they can confide, according to a comprehensive new evaluation of the decline of social ties in the United States. A quarter of Americans say they have no one with whom they can discuss personal troubles, more than double the number who were similarly isolated in 1985. Overall, the number of people Americans have in their closest circle of confidants has dropped from around three to about two. The comprehensive new study paints a sobering picture of an increasingly fragmented America, where intimate social ties -- once seen as an integral part of daily life and associated with a host of psychological and civic benefits -- are shrinking or nonexistent. In bad times, far more people appear to suffer alone. "That image of people on roofs after Katrina resonates with me, because those people did not know someone with a car," said Lynn Smith-Lovin, a Duke University sociologist who helped conduct the study. "There really is less of a safety net of close friends and confidants." If close social relationships support people in the same way that beams hold up buildings, more and more Americans appear to be dependent on a single beam. © 2006 The Washington Post Company

Keyword: Depression
Link ID: 9057 - Posted: 06.24.2010

By Neely Tucker A politician with clinical depression? What kind, the staggering bipolar variety? The fluttering veils of gray known as dysthymia? He's on medication? Is it a mild dosage of Prozac, a few milligrams of Zoloft? Heavyweight dosages of lithium? Twenty, thirty years ago, it wouldn't have mattered. Any open admission of an illness associated with asylums would have been the kiss of political death. It was "One Flew Over the Cuckoo's Nest" territory. Ask Tom Eagleton. But much has changed about the stigma around mental illness, mood disorders and their role in American politics since Eagleton was dumped from the vice presidential spot on the 1972 ballot after it was learned he had undergone electroconvulsive therapy. Back then, they said it was for "nervous exhaustion." Montgomery County Executive Doug Duncan's announcement yesterday that he was dropping out of the Maryland governor's race because of clinical depression startled observers, but mainly because the 50-year-old Duncan had been in public office for more than a dozen years with little indication of depressive behavior. He said yesterday that his family has a history of depression, but he did not elaborate on details of his condition or treatment. He said he had begun medication on Monday. © 2006 The Washington Post Company

Keyword: Depression
Link ID: 9056 - Posted: 06.24.2010

SYDNEY, AUSTRALIA -- Late-onset depression, which first emerges in people aged 60 and over, is linked to a decline in the brain's executive functions that leads to repetitive, negative thought patterns a new study reveals. Executive functions are those that enable people to plan and control their thoughts and actions. Published in the current issue of Cognitive Therapy and Research, the finding is based on a survey of 44 people suffering from depressive symptoms. Aged 66–92 years, the study's participants came from retirement communities in Sydney, Australia. The study's lead author, Bill von Hippel, says evidence for the conclusion is based on three findings. "First, the people with late-onset depressive symptoms showed poorer performance on executive function tests than those with early onset depression." "Executive decline" is a normal part of ageing linked to decreased efficiency in the brain's frontal lobes. Typical signs of executive decline include disinhibition, rigid thinking, inattention and a decline in working memory. "Second, we saw that executive decline was associated with rumination – a tendency for repeated negative thinking patterns -- among those with late-onset depression," says von Hippel, who is associate professor of psychology at the University of New South Wales. "We saw no such link among those who had early-onset depression." "Third, the link between executive decline and late onset depression was brought about by their joint association with rumination. That is, executive decline was only associated with late-onset depression to the degree that it led people to ruminate. When executive dysfunction did not lead to rumination, it did not predict late-onset depression.

Keyword: Depression
Link ID: 9055 - Posted: 06.24.2010

"Crunch time" in our lives may mean no "break time." While some people feel like they don't have time between meetings, appointments, and chores throughout the day, researchers at the Massachusetts Institute of Technology say regular breaks are key to forming memories. David Foster and his colleagues say that when rats take a break while exploring an unfamiliar area, their brains instantly replay the information they've just gathered. As the rats run across a track, certain brain cells fire in a specific sequence. Each cell picks a "favorite place" on the track to go off, and a pattern emerges that is replicated every time the rat repeats the route. This "place cell" effect has been documented for more than 30 years. These place cells lie in the hippocampus, which plays a key role in memory and navigation. Foster's research focuses on this part of the brain, which when damaged, he says, may leave a patient with memory problems similar to those seen in the popular 2000 movie "Memento." But Foster and his colleagues were surprised to learn that when the rats took a break after running the track, the same exact place cells fired in reverse order. Replaying multiple times, these patterns were sped up, Foster says, almost 20 times faster. © ScienCentral, 2000-2006.

Keyword: Learning & Memory
Link ID: 9054 - Posted: 06.24.2010

Most people who knit or crochet know what their finished product will look like. But you never know what's going to come from Daina Taimina's crochet hook. And that's the point, says her husband, David Henderson, as he holds up a convoluted piece that resembles lettuce, or a human brain -- if lettuce or brains were purple, that is. "It actually looks like a brain," Henderson marvels. "And I had no idea it was going to look like that until Daina did it." The couple, both Cornell University mathematicians, study and teach about the strange world of hyperbolic space, in which everything constantly curves away from itself. In hyperbolic space the most basic shapes in regular geometry, like a plain old flat plane, are warped into hard to imagine shapes. "If you have something flat, like a flat floor, flat top or flat tabletop, so then that's a zero curvature, nothing is curved," explains Taimina. "If there is a positive curvature, constant positive curvature that's when we get a sphere. And now the question is, if there is a negative constant curvature, what is it? That's a hyperbolic plane. So in some ways we can say it's opposite of a sphere." © ScienCentral, 2000-2006.

Keyword: Development of the Brain
Link ID: 9053 - Posted: 06.24.2010

By Katherine Unger A symmetrical face is often thought a sign of beauty, but symmetry may be a disadvantage when it comes to the brain. "Left-brained" or "right-brained" fish are more adept at handling multiple activities than fish with no hemispheric preference, according to a new study. Their ability to multitask could help explain why vertebrate brains evolved to function asymmetrically. Scientists used to think that only humans had lateralized, or asymmetric, brains. We generally use the left side of our brain to interpret language and the right to appreciate music, for example. Recently, though, researchers have come to believe that lateralized brains are universal among vertebrates. Some think the condition may allow animals to focus on multiple stimuli at once, with each hemisphere dealing with particular cues. Psychologists Marco Dadda and Angelo Bisazza of the University of Padova in Italy decided to test the theory in fish. They first assembled groups of the minnow Girardinus falcatus that had been bred to be either lateralized or nonlateralized. A right-lateralized fish tends to look at a companion out of its left eye and vice versa, because hemispheres process vision on the opposite side of the body. A nonlateralized fish does not favor either eye. When the researchers placed each type of fish in a glass tank and gave it shrimp to eat, they found that lateralized and nonlateralized fish took about the same time to catch 10 shrimp. In addition, both groups caught the shrimp at equal rates on both sides of their bodies, indicating that they weren't favoring either eye while scoping out their prey. © 2006 American Association for the Advancement of Science.

Keyword: Laterality
Link ID: 9052 - Posted: 06.24.2010

Susan Milius On his first trip into Namibia, Chris Faulkes woke up in his tent with a peculiar kink in his back. The ground beneath him had been flat enough when he went to sleep. Yet the next morning, "there was a whopping great lump," he says. A mound of dirt had arisen under Faulkes. He'd inadvertently found—or been found by—Damaraland mole rats, the very creatures he'd come to study. With one of the oddest social systems yet found in mammals, these sub-Saharan rodents spend their lives in networks of underground tunnels that they continually excavate. These mole rats and a better-known species called naked mole rats survive in land that goes months without rain. When rain finally comes, the animals go into a frenzy of digging to expand their tunnels before the ground bakes again. With the mole rats' extreme social system, individuals labor for the sake of the colony. Since the early 1980s, mole rats have been used as models of social organization. The wrinkled, hairless rodent known as the naked mole rat has achieved celebrity status even outside science. In Faulkes' office at Queen Mary College of the University of London stands a cardboard cutout of the Disney-cartoon character of the naked mole rat Rufus. Even the Wall Street Journal has run a page-one story on naked mole rat charms. The subhead read: "What Is Whiskered and Ugly and Has Little Squinty Eyes?—No, Not Your Former Spouse. . . ." Copyright ©2006 Science Service

Keyword: Animal Communication; Sexual Behavior
Link ID: 9051 - Posted: 06.24.2010

Bruce Bower Given all the bad news that science has delivered about brain cells withering and memory waning as the years mount, older people have a right to be cranky. But, instead, the over-50 crowd handles life's rotten realities and finds life's bright side more effectively than whippersnappers do. In no small part, that's because the aging brain makes critical emotional adjustments, a new study indicates. Advancing age heralds a growth in emotional stability accompanied by a neural transition to increased control over negative emotions and greater accessibility of positive emotions, according to a team led by neuroscientist Leanne M. Williams of Westmead (Australia) Hospital. A brain area needed for conscious thought, the medial prefrontal cortex, primarily influences these emotional reactions in older adults, Williams and her colleagues say. In contrast, people under age 50 experience negative emotions more easily than they do positive ones. These younger adults' emotion-related activity centers on the amygdala, a brain structure previously implicated in automatic fear responses. This gradual reorganization of the brain's emotion system may result from older folk responding to accumulating personal experiences by increasingly looking for meaning in life, the researchers propose in the June 14 Journal of Neuroscience. Copyright ©2006 Science Service.

Keyword: Emotions; Alzheimers
Link ID: 9050 - Posted: 06.24.2010

By Michael Purdy -- An epilepsy drug that has been on the market for decades can ease the symptoms of adult sufferers with a genetic disorder that seriously weakens muscles. Scientists at Washington University School of Medicine in St. Louis retrospectively reviewed results from off-label use of the drug valproate to treat seven adult spinal muscular atrophy (SMA) patients. Clinicians offered the drug to patients on the basis of research conducted elsewhere that showed the drug increased levels of a key protein in cell cultures. "The treatment has been fairly successful," says lead author Chris Weihl, M.D., Ph.D., a postdoctoral fellow in neurology. "The drug appeared to be well-tolerated and increased the strength of the patients who took it." The study, now available online, will appear in the August 8 issue of Neurology. Weihl notes that a larger, prospective trial is needed to firmly establish valproate as a treatment of choice for sufferers of this type of SMA. Such trials are already underway elsewhere in pediatric patients who suffer from a different type of SMA that begins earlier in life. Weihl and his colleagues are concerned that valproate may not work as well in those patients. They wanted to make sure that researchers did not discard the possibility that valproate could help older sufferers even if the trials in pediatric patients went poorly.

Keyword: Movement Disorders; Epilepsy
Link ID: 9049 - Posted: 06.24.2006

Howard Hughes Medical Institute researchers have discovered that neurons in the brains of mice sprout robust new connections when the animals are adjusting to new experiences. The new connections alter the circuitry of the brain by changing communication between neurons. The researchers said their findings aid understanding of how procedural learning induces long-term rewiring of the brain. This type of learning is used in mastering skills such as riding a bicycle or typing on a computer. Howard Hughes Medical Institute (HHMI) investigator Karel Svoboda and his colleagues reported their findings in the June 22, 2006, issue of the journal Nature. Other co-authors of the paper included Anthony Holtmaat and Linda Wilbrecht in Svoboda's laboratory at Cold Spring Harbor Laboratory; and Graham Knott and Egbert Welker at the University of Lausanne in Switzerland. Svoboda is one of a handful of researchers in the world who are pioneering the development of new tools and techniques that permit scientists to observe the brain as it rewires over a period of weeks or months. This summer Svoboda will move to HHMI's Janelia Farm Research Campus where he will pursue neurobiology studies and projects in optics and microscopy. In the studies reported in Nature, the researchers used mice that were genetically altered to produce a green fluorescent protein in specific neurons in the neocortex, which is a region of the brain that is known to adapt to new experiences. © 2006 Howard Hughes Medical Institute.

Keyword: Learning & Memory
Link ID: 9048 - Posted: 06.24.2010

By SUSAN SAULNY NEW ORLEANS, — Sgt. Ben Glaudi, the commander of the Police Department's Mobile Crisis Unit here, spends much of each workday on this city's flood-ravaged streets trying to persuade people not to kill themselves. Last Tuesday in the French Quarter, Sergeant Glaudi's small staff was challenged by a man who strode straight into the roaring currents of the Mississippi River, hoping to drown. As the water threatened to suck him under, the man used the last of his strength to fight the rescuers, refusing to be saved. "He said he'd lost everything and didn't want to live anymore," Sergeant Glaudi said. The man was counseled by the crisis unit after being pulled from the river against his will. Others have not been so lucky. "These things come at me fast and furious," Sergeant Glaudi said. "People are just not able to handle the situation here." New Orleans is experiencing what appears to be a near epidemic of depression and post-traumatic stress disorders, one that mental health experts say is of an intensity rarely seen in this country. It is contributing to a suicide rate that state and local officials describe as close to triple what it was before Hurricane Katrina struck and the levees broke 10 months ago. Copyright 2006 The New York Times Company

Keyword: Depression
Link ID: 9047 - Posted: 06.24.2010