By ABIGAIL ZUGER Like the finish line of a long road race, the Times Square subway platform one recent hot afternoon was a study in wet humanity, from drenched (a large woman in shorts and a skimpy, sweat-splotched top, flushed and vigorously fanning herself), to barely bedewed (an elderly man in a suit and tie calmly reading his paper). Who would believe that every sufferer had the same model of personal air-conditioner operating at full blast? Sweat is our interior coolant, part of a uniquely human biologic machine. The machine drips and occasionally stalls: long waits on torpid platforms can inspire glum reflections on how it will hold up as the planet heats up. But experts counsel optimism: the system is sturdy, adjustable and even reproducible by engineers working to make our future sweaty selves more comfortable. Humans operate in a tiny range of preferred internal temperatures. We can tolerate overcooling, routinely recovering from long periods of hypothermia with body temperatures diving 20 or more degrees below normal. But we have little tolerance for even brief overheating: the brain malfunctions with six or seven degrees of fever, and an internal temperature of 110, barely a dozen degrees above normal, is often cited as the upper limit compatible with life. So a good internal air-conditioner is essential, both to dissipate the heat generated by the body’s metabolism and to relieve the heat absorbed from miserable summer weather. Copyright 2007 The New York Times Company

Keyword: Miscellaneous
Link ID: 10601 - Posted: 06.24.2010

They look like the makings of quite a headache. But these electrodes, which act much like a heart pacemaker, actually stimulate the brain. DBS, or deep brain stimulation, is sometimes administered to people with Parkinson's disease, depression, epilepsy and obsessive-compulsive disorders when "other traditional options are not optimal," says Ali R. Rezai, the director of Cleveland Clinic's Center for Neurological Restoration. Rezai and his team have also used DBS to reawaken a brain-damaged patient from a minimally conscious state. As they reported earlier this month, surgeons implanted two electrodes in the patient's thalamus, an area that controls arousal, communication and the integration of information, says Rezai. A device located under the skin of the chest sends electricity via the electrodes to the brain. The force and timing of those signals are controlled by doctors. Although not yet functioning at 100 percent, the patient is able to speak, chew, swallow, and demonstrate motions like brushing his teeth when his DBS device is on. But doctors caution that his case could be unusual: DBS may not help with permanently vegetative patients or even others in a minimally conscious state. © Copyright 1996-2007 The Washington Post Company

Keyword: Attention
Link ID: 10600 - Posted: 06.24.2010

By Elizabeth Svoboda Seven years ago, Robert Gesteland, a biologist at the University of Cincinnati, and his colleague Robert Frank, a psychologist, decided to tackle a perplexing topic: why some people are more open to trying unfamiliar foods. Suspecting that picky eaters might be more attuned to strong smells, they set about trying to quantify this. "Someone turned up the suggestion that people might take smaller sniffs once they detect a smell," Gesteland said. "It was natural for me to say, 'How can we measure that? Let me see what I can put together in the garage.' " Since then, the apparatus he built at his home workbench has evolved into a device called the Sniff Magnitude Test - and one the two scientists are using for a much different purpose. As the only test that measures patients' ability to smell without requiring them to put the sensation into words, it shows promise in helping detect neurodegenerative disorders like Alzheimer's and Parkinson's in their earliest stages. Doctors have known for years that when people with these diseases begin the slide toward dementia, an inability to smell is often the first sign of a problem. Because comparatively few brain cells are devoted to processing odors, "there's good reason to think the olfactory system is affected very early on with these conditions," said Richard Doty, director of the University of Pennsylvania's Smell and Taste Center, who has done research comparing the Sniff Magnitude Test with other smell-assessment measures. "Many patients tell their doctors they can't smell years before they actually get Alzheimer's or Parkinson's." © 2007 the International Herald Tribune

Keyword: Chemical Senses (Smell & Taste); Alzheimers
Link ID: 10599 - Posted: 06.24.2010

If you're so smart, why aren't you rich? Although money and mental muscles may seem a natural match, brains, alas, may be more hindrance than help when it comes to getting rich, concludes a new study in the journal Intelligence. "It is still not well understood why some people are rich and others are poor," writes study author Jay Zagorsky of Ohio State University. "Luck, timing, parents, choice of spouse and many other factors play important roles in shaping an individual's circumstances," he acknowledges in his study, which looks for a link between intelligence scores, wages and wealth. Past analyses have mostly just looked at income, with studies of World War II veterans finding a link between smarts and a better salary. The controversial 1994 book, The Bell Curve, by Richard Herrnstein and Charles Murray, went further, arguing that few high-IQ types end up in poverty. Within a few years, that conclusion was later found lacking by Cornell University economist John Cawley and others. But what good is it to be smart and have a better salary if you end up broke or spending it all on credit card bills? asks Zagorsky. Looking at the National Longitudinal Survey of Youth 1979's latest round of survey answers from more than 7,000 randomly-selected participants, he tries to tackle the question of whether better IQs lead to bulging bank accounts and less bankruptcy. (Funded by the federal Bureau of Labor Statistics, the NLSY 1979 has questioned the same people 21 times from 1979 to 2004, with participants now ranging in age from 33 to 41 and almost evenly split between men and women.) Copyright 2007 USA TODAY

Keyword: Intelligence
Link ID: 10598 - Posted: 08.15.2007

By Nikhil Swaminathan Scientists have determined that the death of two distinct populations of neurons in the brain trigger symptoms of Parkinson's disease. Neuroscientists have long believed that the tremors, stiffness and sluggish gait characteristic of Parkinson's disease resulted from the death of neurons in a section of the midbrain that produce the neurotransmitter dopamine, which helps to maintain proper motion control. A new study in mice, however, suggests that the disorder may actually be caused not only by hobbled dopamine-producing cells but also by neurons in the locus coeruleus region of the brain stem that produce norepinephrine, a chemical related to dopamine and associated with everything from anxiety to attention to blood pressure regulation. The new finding could lead to new therapies for combating the debilitating condition. Researchers previously believed that Parkinson's, which affects an estimated 500,000 Americans, most over 60, was triggered when 80 percent of the dopamine-producing neurons in the substantia nigra region of the midbrain died, disrupting the signaling between that structure and another midbrain region called the striatum, which controls motion. But David Weinshenker, an associate professor of human genetics at Emory University in Atlanta and senior author of the study published in Proceedings of the National Academy of Sciences USA, says autopsies on Parkinson's-ravaged brains showed a concurrent loss of norepinephrine-producing cells as well. "The death of norepinephrine neurons has been known among neuropathologists for decades," he says, yet the cells had not been linked to the causation of Parkinson's symptoms. © 1996-2007 Scientific American, Inc.

Keyword: Parkinsons
Link ID: 10597 - Posted: 06.24.2010

Scientists have taken a big step towards a quick, sensitive test for the proteins that go haywire in mad-cow disease. Because people or animals can be infected for years without showing symptoms, the researchers say developing a better test will be key to preventing a silent epidemic. Right now, the only method that blood banks have for keeping deadly mad cow disease (called variant Creutzfeldt Jakob Disease, or vCJD ) out of the blood supply is with donor questionnaires. National Institutes of Health researcher Byron Caughey has been searching for a better way for more than a decade. "There have been several examples now where it's documented that humans who've received blood transfusions from other people, who unbeknownst to anyone had CJD, have actually come down with CJD themselves," Caughey says. By the time prion diseases cause sickness and death, huge amounts of the infectious misfolded proteins can be easily found in the brain. Yet the infection can start off with only tiny amounts of prions. "It can take from months to decades depending on the particular prion disease and the species, but during that time, infected individuals can serve as carriers of the disease," says Caughey. "It really is key to be able to pick up those otherwise invisible infections, prion infections before any potential transmissions to others can occur." © ScienCentral, 2000-2007

Keyword: Prions
Link ID: 10596 - Posted: 06.24.2010

Jennifer Viegas, Discovery News — Mental disorders associated with aging, including Alzheimer's, are far more common in domesticated cats than previously realized, with more than half of all cats over age 15 showing signs of senility, according to a forthcoming Journal of Small Animal Practice paper. The findings support a growing body of evidence suggesting that most, if not all, mammals, can suffer age-related conditions normally associated with people. In the case of cats, the main difference is that a 15-year-old individual can be compared to an 85-year-old person. Another recent study found that about half of all octogenarians, too, show signs of dementia. The behaviors associated with senility in cats range from acting disoriented to changes in their social relationships, to shifting sleep habits, said lead author Danielle Gunn-Moore, head of the Feline Clinic at the University of Edinburgh's Hospital for Small Animals. They may also include inappropriate vocalizing, forgetting commands, breaking housetraining, pacing, wandering, sluggishness, unusual interest or disinterest in food, and decreased grooming and confusion, such as "forgetting that they have just been fed," said Gunn-Moore. © 2007 Discovery Communications

Keyword: Alzheimers
Link ID: 10595 - Posted: 06.24.2010

Roxanne Khamsi Adolescents who claim they are "madly in love" might not be too far off the mark: a new study suggests that they show almost manic behaviours. Serge Brand of the Psychiatric University Clinics in Basel, Switzerland, and his colleagues surveyed 113 teenagers at around 17 years of age, asking them to complete questionnaires about their conduct and mood and to keep a log of their sleep patterns. Of those, 65 indicated they had recently fallen in love and experienced intense romantic emotions. The lovestruck teenagers showed many behaviours resembling "hypomania" – a less intense form of mania. For example, they required about an hour less sleep each night than teens who didn't have a sweetheart. They were also more likely to report acting compulsively, with 60% saying they spent too much money compared with fewer than 30% of teenagers who were not in love. Moreover, the lovestruck teens were more than twice as likely to say they had lots of ideas and creative energy. Worryingly, they were also more likely to say they drove fast and took risks on the road. "We were able to demonstrate that adolescents in early-stage intense romantic love did not differ from patients during a hypomanic stage," say the researchers. This leads them to conclude that intense romantic love in teenagers is a "psychopathologically prominent stage". © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior; Attention
Link ID: 10594 - Posted: 06.24.2010

By Hannah Devlin No matter how much Homer Simpson eats, the lovable cartoon character still salivates at the mere sight of food. Homer's animated brain might be lacking a hormone called leptin, if one accepts a new study indicating that the protein is a key player in control of food cravings. The research, published online yesterday in Science, has wider implications for understanding the way the brain regulates appetite and, ultimately, the causes of obesity. Leptin is already known to be a key player in appetite, acting as a sensor for the body's energy storage (ScienceNOW, 1 November 2001). Fat tissue releases leptin into the bloodstream, signaling the brain that the body has had enough to eat. When fat stores become depleted, leptin levels fall and the brain stimulates hunger. But researchers have been unclear whether the hormone affects the higher brain areas that mediate feelings of craving and reward. Endocrinologist Sadaf Farooqi of the University of Cambridge, U.K., and her colleagues addressed question this by studying a 14-year-old boy and a 19-year-old girl unable to produce leptin. Using functional magnetic resonance imaging (fMRI), the researchers scanned the brain activity of the volunteers in their natural (leptin-deficient) condition, once in a fasted state and again after eating. During each scan, the subjects were shown pictures of food and nonfood control images. The volunteers showed greater activation in reward-related brain areas in response to the food images, regardless of whether they had eaten, and they consistently rated the food images as highly desirable. The volunteers were then treated with leptin for 7 days, and the fMRI scans were repeated in fed and fasted states. This time, the volunteers only showed the greater brain activation with food images if they had been fasting, and on average they rated the food images as less desirable if they had eaten. © 2007 American Association for the Advancement of Science

Keyword: Obesity; Drug Abuse
Link ID: 10593 - Posted: 06.24.2010

Kerri Smith Do you feel a yawn coming on just looking at this picture? Yawning is known to be contagious — but the rule doesn't apply to autistic children. This finding could shed light on the social impairments of people with autism. Atsushi Senju of Birkbeck College in London and his colleagues wanted to test the theory that contagious yawning is affected in people with autism. This kind of yawning is thought to be based at least partly on the capacity for empathy, which is compromised in autistic persons. The researchers showed video clips of people either yawning or simply opening and closing their mouths to 49 children who were 7 years or older, half of whom were autistic. The yawning faces triggered more than twice as many yawns in non-autistic children than in their autistic counterparts, they report in Biology Letters1. When shown the faces that were not yawning, however, both groups yawned about the same very infrequent amount, so the difference was not because non-autistic children simply yawn more in general. The study was done with children in part because they are less likely to consciously suppress a yawn than adults; but the researchers expect that autistic adults would also be less susceptible to contagious yawning. ©2007 Nature Publishing Group

Keyword: Autism
Link ID: 10592 - Posted: 06.24.2010

Jeff Hecht It's Californian ground squirrel versus rattlesnake in a potentially lethal showdown. But the squirrel has a secret weapon that until now has remained invisible to the human eye. The ground squirrel heats up its tail then waves it in the snake's face - a form of harassment that confuses the rattler, which has an infrared sensing organ for detecting small mammals. This defensive tactic remained invisible to biologists until they looked at the animals through an infrared video camera. Now they believe that many other animals might be using infrared weaponry to ward off potential predators. Young California ground squirrels (Spermophilus beecheyi) are easy prey for snakes, so protective adults harass the predators while puffing up their tails and wagging them. Graduate student Aaron Rundus and his supervisor Donald Owings of the University of California, Davis, wondered how this might affect the snakes’ interaction with the adult squirrels. So he borrowed a $35,000 infrared camera from another scientist and spied on squirrel-snake stand-offs. © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 10591 - Posted: 06.24.2010

Caffeine may help older women ward off mental decline, research suggests. French researchers compared women aged 65 and older who drank more than three cups of coffee per day with those who drank one cup or less per day. Those who drank more caffeine showed less decline in memory tests over a four year period. The study, published in the journal Neurology, raises the possibility that caffeine may even protect against the development of dementia. The results held up even after factors such as education, high blood pressure and disease were taken into account. Caffeine is a known psychostimulant, but this study appears to suggest its effects may be more profound. However, lead researcher Dr Karen Ritchie of the French National Institute for Health and Medical Research warned against jumping to premature conclusions. She said: "While we have some ideas as to how this works biologically, we need to have a better understanding of how caffeine affects the brain before we can start promoting caffeine intake as a way to reduce cognitive decline. "But the results are interesting - caffeine use is already widespread and it has fewer side effects than other treatments for cognitive decline, and it requires a relatively small amount for a beneficial effect." The study, which involved 7,000 women, did not find that caffeine consumers had lower rates of dementia. Dr Ritchie said: "We really need a longer study to look at whether caffeine prevents dementia; it might be that caffeine could slow the dementia process rather than preventing it." She said it was not clear why the protective effect did not seem to apply to men. (C)BBC

Keyword: Learning & Memory; Drug Abuse
Link ID: 10590 - Posted: 08.10.2007

David Perlman, Chronicle Science Editor A trove of fossil skulls, teeth and bones more than a million years old and discovered in Africa has opened a new controversy over the lineage of our early human ancestors: Just who descended from whom, and how long ago did they do it? Scientists have long believed that two species of humanlike creatures were direct forebears of our own Homo sapiens tribe, but the discoverers of the newly described fossils suggest the two species were not directly ancestral at all. Instead, the anthropologists conclude, they lived at the same time in the same African lake region for at least half a million years, and one of them may well have been more apelike than human. The finds from the Lake Turkana region of Kenya were announced Wednesday by a team of anthropologists headed by Maeve Leakey, the legendary fossil hunter, plus her anthropologist daughter Louise and her principal colleague, Fred Spoor of University College London. But other anthropologists promptly challenged the team's conclusions. Such disputes are by no means rare in the contentious field of paleoanthropology, for ancient bones must often be dug from solid rock and are more often than not in bad shape for positive analysis. Their significance is often argued for years. © 2007 Hearst Communications Inc.

Keyword: Evolution
Link ID: 10589 - Posted: 06.24.2010

Kerri Smith The way in which antidepressants exert their effects on brain cells has been revealed by two separate teams of researchers working independently of each other. Antidepressants work by preventing neurons in the brain from importing certain chemicals, such as dopamine and serotonin, which are used to pass messages from cell to cell. The route by which these chemicals are imported depends on passageways in the outer membrane of the cells called transporter proteins, and it is on these passageways that the antidepressants exert their influence. But how exactly they hold up the process has remained a mystery since the drugs were discovered 45 years ago, says Les Iversen, a pharmacologist at the University of Oxford, UK. To resolve the mystery, both teams — one led by Eric Gouaux of Oregon Health and Science University in Portland and the other based at New York University and led by Da-Neng Wang — set out to understand what happens when antidepressants lock onto a transporter at the most fundamental level. They zoomed in on the transporters' molecular structures as revealed at atomic resolution through X-ray crystallography. The researchers couldn't use human transporter proteins because they are difficult to isolate and fall apart easily. Instead they used an equivalent found in bacteria called LeuT. They then selected drugs from a class called tricyclic antidepressants and created crystals in which the drug and the transporter were bound together. Gouaux's team used a drug called clomipramine while Wang's used a similar compound called desipramine. ©2007 Nature Publishing Group

Keyword: Depression
Link ID: 10588 - Posted: 06.24.2010

Heidi Ledford A US government-appointed scientific panel has said it has "some concern" that a compound found in many plastics may cause neural and behavioural abnormalities in infants and children at concentrations normally found in humans. But the panel found negligible concern that those exposed to typical levels of the compound, called bisphenol A, would develop reproductive problems or birth defects. The panel, which announced its findings on Wednesday 8 August, was convened by a division of the National Institute of Environmental Health Sciences (NIEHS) called the Center for the Evaluation of Risks to Human Reproduction (CERHR). Its report will now undergo review by the US National Toxicology Program and there will be two additional public comment periods before it is finalized. At that point it could serve as the basis for subsequent regulation of bisphenol A. The findings stand in stark contrast to the conclusions of an independent scientific panel assembled by Jerrold Heindel, a scientist who is also at the NIEHS. That panel published a consensus statement a week ago, citing its conclusion that prenatal or neonatal bisphenol A exposure alters the prostate, breasts, testes, mammary glands, body size, and behaviour later in life. The consensus statement was published along with two new bisphenol A studies to appear in the journal Reproductive Toxicology1,2, but the reports came too late for consideration by the CERHR panel, says its chair, Robert Chapin of Pfizer. ©2007 Nature Publishing Group

Keyword: Development of the Brain
Link ID: 10587 - Posted: 06.24.2010

Using electrical energy to zap cancer cells may sound like a strange idea. But clinical trials at twelve major hospitals around the country are now testing it against the deadliest form of brain cancer. In this ScienCentral News video, you'll hear from one study participant who a year ago was given only six months to live. Michael Quatrano's head is covered with electrodes and he's tethered to cable-box-sized electrical device and battery pack -- minor inconveniences after the surgery, radiation and chemotherapy that failed to stop his aggressive brain tumor from growing. Last August, Quatrano was diagnosed with Glioblastoma Multiforme (GBM), the most common and lethal type of brain cancer. He'd had periodic headaches before, so when he went to the emergency room for what he thought was a migraine, he expected to be treated with pain medication. "I thought I was going for a regular migraine and they said I had cancer," says Quatrano. "[The surgeon] went in my head and cut it and drained it as much as he could. And he told me that it looked really bad and I had six months to live. Right away, I've had people in my family that's had cancer, so I knew I've got to fight. So I don't give up." Quatrano had radiation and chemotherapy to shrink the tumor. "Then what happened, two weeks after I stopped, the tumor grew again," he says."This was like the last alternative. And luckily, it's working out." © ScienCentral, 2000-2007.

Keyword: Miscellaneous
Link ID: 10586 - Posted: 06.24.2010

By Krista Zala Give your skeletal system some credit. Not only do your bones keep you upright, they produce red and white blood cells, store minerals, and help control pH. But that's not all: According to a new study, bones secrete a protein called osteocalcin that regulates sugar and fat absorption. The finding qualifies osteocalcin as a hormone, meaning the skeleton can now add being an endocrine organ to its impressive list of accomplishments. There have already been hints that the skeletal system and the hormone-releasing endocrine system are intertwined. Gerard Karsenty, a geneticist at Columbia University, showed that fat cells regulate bone mass, for example, by releasing the hormone leptin, which affects the number of bone-building osteoblast cells. Considering the prevalence of feedback systems in the body, he and colleagues wondered whether bones might release their own hormones to influence fat metabolism. They knew that bones secrete a protein called osteocalcin, which helps pack calcium into the skeleton, but because no one had observed this protein acting elsewhere in the body, it was not classified as a hormone. Still, Karsenty and colleagues observed that mice unable to make osteocalcin grow obese, suggesting it might work as a hormone. So Karsenty's team genetically engineered one set of mice to produce loads of osteocalcin and another set not to make it at all. When fed regular diets, the mice making extra osteocalcin had lower-than-normal blood glucose levels and higher insulin levels than regular mice. © 2007 American Association for the Advancement of Science.

Keyword: Hormones & Behavior; Obesity
Link ID: 10585 - Posted: 06.24.2010

Coping well with stress can cut the risk of a stroke by almost a quarter, research shows. A University of Cambridge team based their conclusion on a seven-year study of more than 20,000 people. The study, published in the journal Stroke, recorded 452 strokes and more than 100,000 stressful life events among the participants. Those who were able to take a well-rounded approach to problems had a 24% lower risk of stroke. This group were said to have a good sense of coherence - a term coined following research into the experiences of survivors of concentration camps. Lead researcher Dr Paul Surtees, from the University of Cambridge, said: "Our findings suggest that people who are able to adapt more rapidly to stressful circumstances in their lives had a lower risk of stroke. "Whilst many questions remain to be answered by further research, this evidence raises the possibility that improving our ability to respond to stress may have benefits for vascular health." Dr Surtees said the relationship between stress and stroke was probably complex. However, he said there was a wealth of anecdotal evidence suggesting a link between the two. For instance, in the three months following the Kobe earthquake in Japan in 1995 stroke rates among the local population rose by 90%. (C)BBC

Keyword: Stress; Stroke
Link ID: 10584 - Posted: 08.09.2007

Women do not see macho men as a sound bet for a long-term partnership, preferring those with more feminine features, a study suggests. Men with masculine features like large noses and small eyes were seen as less warm, less faithful and worse parents than more feminine counterparts. Some 400 British men and women made judgements after viewing photographs in which the features were subtly altered. The study appears in the journal Personality and Individual Differences. Lead author Dr Lynda Boothroyd of Durham University said: "This research shows a high amount of agreement between women about what they see, personality-wise, when asked to judge a book by its cover. "They may well use that impression of someone to decide whether or not to engage with that person. That decision-making process all depends on what a woman is looking for in a relationship at that stage of her life." Some 400 British men and women completed the web-based test which put a pair of pictures in front of them. Participants were asked to judge the faces on the following categories: dominance, ambition, wealth, faithfulness, commitment, parenting and warmth. They did so by clicking on the point of a scale. The differences were subtle but apparent to the trained eye. The feminine face had more curved eyebrows, an arched forehead and slightly higher cheekbones. He also wore a hint of a smile, as women smile more often than men, the researchers said. (C)BBC

Keyword: Sexual Behavior
Link ID: 10583 - Posted: 08.09.2007

By ERIC NAGOURNEY Just can’t manage to nail down the subjunctive tense in French or the difference between the Spanish verbs for “to be”? Blame your Heschl’s gyrus — or at least your left one, anyway. That is a tiny part of the brain that appears to play an important role in how well adults can learn another language, a new study finds. Writing online in the journal Cerebral Cortex, researchers said people who had a larger left Heschl’s gyrus seemed to have an easier time picking up foreign languages. As a practical matter, a beefier H.G., as it is known, may not really help with the subjunctive or the difference between “ser” and “estar” in Spanish. For this study, the researchers, led by Dr. Patrick C. M. Wong of Northwestern, were focusing on the ability to discern pitch, a key element of tonal languages, not vocabulary. In tonal languages like Chinese, which are spoken by most of the world’s population, the same word can have different meanings, depending on how it is inflected. Copyright 2007 The New York Times Company

Keyword: Language
Link ID: 10582 - Posted: 06.24.2010