By Carolyn Y. Johnson CAMBRIDGE - Studying a species known to chase its own tail may seem an unlikely way to better understand the human mind. But scientists at Harvard University's new Canine Cognition Lab hope to gain insight into more than the psychology of dogs from visiting pet pooches - including an alert German shepherd named Celia and a rottweiler called Taylor who loves to eat chicken. Researchers have long looked at other species' reasoning abilities and behavior to discern what makes humans distinct. The Harvard team is now turning to dogs because on certain tasks, such as understanding pointing, dogs easily outperform animals much more closely related to humans, even chimpanzees. Scientists are also drawn to dogs because of their unique history growing up in the same environment as people, and they hope to learn whether domestication has led to dogs that think and act more like their masters - or whether we just think they have human traits. "Here's this species we live with. Everyone has their views about how smart they are. No doubt we are overinterpreting - and in some cases underinterpreting," said Marc Hauser, a Harvard professor who has long studied cognition in cottontop tamarin monkeys and who heads the new lab. "To what extent is an animal that's really been bred to be with humans capable of some of the same psychological mechanisms?" Can dogs understand such abstract concepts as "same," for example? Or, can dogs be patient? To answer such canine conundrums, Hauser is recruiting both purebreds and mutts and running them through simple tests. In return, they earn tasty treats. © 2009 NY Times Co

Keyword: Intelligence; Evolution
Link ID: 12763 - Posted: 06.24.2010

By Coco Ballantyne Cholesterol-busting statins may lower the odds of suffering from a heart attack or stroke, but they don't appear to ward off dementia as researchers had hoped, a new review of clinical trials suggests. "There is really no evidence that statins do prevent dementia, especially in elderly people (age 70 and older)," says Bernadette McGuinness, a geriatrician at Queen's University in Belfast, Ireland, and co-author of the study published today in The Cochrane Library. McGuinness and her colleagues analyzed the findings of two large clinical trials probing the health effects of statins: the Medical Research Council/British Heart Foundation Heart Protection Study (HPS), which investigated the effects over five years of simvastatin (Zocor) in 20,536 patients, and The Prospective Study of Pravastatin in the Elderly at Risk (PROSPER) trial, which followed 5,804 patients taking pravastatin (Pravachol) for an average of 3.2 years. Participants in these trials ranged in age from 40 to 82. In both studies, the odds of developing Alzheimer's and other forms of dementia were about the same among patients taking statins and not taking statins, McGuinness says. Earlier research has suggested that statins might help reduce the risk of developing Alzheimer's by lowering cholesterol, which helps in the production of beta-amyloid protein (the suspected culprit in the disease), says Benjamin Wolozin, a neuroscientist at Boston University. © 1996-2009 Scientific American Inc

Keyword: Alzheimers
Link ID: 12762 - Posted: 06.24.2010

By Sydney Spiesel Autism can present in many ways—hence "autism spectrum disorders"—but that range is nothing compared with the diverse techniques that parents use in their attempts to cure, ameliorate, or disrupt the progress of the disease. In the 60-plus years since autism was first described, many methods to treat it have been proposed—one research paper identified 111 recognized treatments or strategies. Studies have found that parents try an average of between 4.3 and seven interventions simultaneously; one family reported using 47 different treatments at one time. Alas, almost none of these treatments are evidence-based, and some have been clearly demonstrated to be worthless. In dealing with other medical problems, like the common cold, I've always annoyed medication-seeking parents by pointing out the obvious: If there is any illness for which 100 treatments are available, you can be sure that none of them works. But with autism, the stakes are much higher. It is especially difficult to know where to look for treatments when a condition is poorly defined and characterized. There are no laboratory tests or gross anatomical findings that establish the diagnosis, but experienced clinicians often "know it when they see it" almost instantly, especially when patients are severely affected. I once made the diagnosis from a dog-eared snapshot. Since most of the ways we diagnose autism are based on behavior, we can't rely on biological, structural, or chemical findings to determine if a treatment is working. We primarily measure success based on a patient's change, or lack thereof, in behavior. 2009 Washington Post.Newsweek Interactive Co. LLC

Keyword: Autism
Link ID: 12761 - Posted: 06.24.2010

by Celeste Biever Savant-like skills, such as astounding memory, perfect pitch or the ability to multiply very high numbers together, may be much more common among people with autism than previously thought. A new study of about 100 adults with autism shows that one third have skills that stand out, both in comparison with their other abilities and with the skills of the general population. Previous studies put the prevalence of savantism in autistic people as around 1 in 10. "People often focus on the things people with autism can't do," says Patricia Howlin of the Institute of Psychiatry at King's College in London, who led the study. "One of the things our study illustrates is that these are people who do have special skills but they are not being used." The notion of the savant – someone who has a skill that is exceptional both compared to the general population and to that person's other skills – has long captured the imagination of cognitive scientists and the general public alike. But despite this fascination, the connection between autism and savantism remains mysterious. Some studies indicate that there are more savants within the autistic population than among the general population and among the populations of people with other mental difficulties. Putting an exact figure on the prevalence of such special skills among people with autism, however, has proved difficult. © Copyright Reed Business Information Ltd.

Keyword: Autism
Link ID: 12760 - Posted: 06.24.2010

by Ewen Callaway If rollercoasters and rock concerts sound fun but leave you with a headache, a drug-free sugar pill might be all that's needed to soothe you. Thrill-seekers enjoy a stronger placebo response than people with more restrained personalities, new research shows. It's too early to prescribe phoney pain treatments based on personality tests, says neuroscientist Petra Schweinhardt, of McGill University in Montreal, whose team tested 22 male university students. But if confirmed in larger trials, her team's findings could help pharmaceutical companies avoid testing experimental drugs on people with strong placebo responses, she says. Her team injected a pain-inducing saline solution into the left and right legs of willing volunteers for 20 minutes. "It's a dull pain, a dumb pain, it's aching, it's annoying," she says. Before the injection, her team told volunteers they were testing an experimental analgesic cream – really just skin lotion. To make the ruse more believable, researchers said they would test one leg with the treatment and one leg with a non-medicated lotion. "We really told them the whole story in order to counteract any doubts in the treatment," Schweinhardt says. Volunteers then rated their pain across both trials, and the difference amounted to the placebo response. © Copyright Reed Business Information Ltd.

Keyword: Pain & Touch
Link ID: 12759 - Posted: 06.24.2010

by Richard Webb I WAS rounding the corner to the bus stop when it hit me - a bright shaft of sunlight smack between the eyes. My reaction was immediate: an unpleasant prickling in my nose, a quickening of my breath, an uncontrollable watering of my eyes. Then, almost as quickly as the sensation came, relief, blessed relief. Aaaaa-tisshoo! A sneeze. It wasn't the first time. In fact, the same thing happens every time I go into the sun. For a long time, I thought it was a quirk all of my own. Then a friend mentioned she was similarly afflicted. Next my mother came out of the closet. With a bit of digging around I came to a startling realisation: not only am I not alone, but the "photic sneeze reflex" is actually common. Quite how common, no one knows exactly - but anything between 1 in 10 and 1 in 3 of us might be affected. The more I looked, the more mysterious things became. Sunlight is the most widespread, but by no means the only, odd stimulus that sets off sneezing. Thinking about sex, eyebrow tweezing, eating chocolate or a mint, or drinking a glass of wine - all these activities can leave us groping around for handkerchiefs. Members of one Kuwaiti family were even reported to sneeze whenever they had a full stomach - a phenomenon dubbed "snatiation". Then there was the case of the medical student who sneezed with almost clockwork precision around 8.20 every morning. © Copyright Reed Business Information Ltd.

Keyword: Miscellaneous
Link ID: 12758 - Posted: 06.24.2010

By Kayt Sukel Research has shown that lead kills neurons (nerve cells), resulting in smaller brains. It has long been hypothesized that such changes in the brain caused by childhood lead exposure may be behind a higher incidence of poor cognitive performance and criminal behavior. And although it is difficult to disentangle the confounding effects of race, class and economics, a recent study by Kim Dietrich, a professor of environmental health at the University of Cincinnati, found that individuals who suffered from the highest lead exposure as children had the smallest brain sizes—as well as the most arrests. "That early lead exposure was associated with smaller volumes of cortical gray matter [the parts of the brain rich in neural cell bodies and synapses] in the prefrontal area," he says. "And the fact that we saw both criminal behavior and volume loss in this critical area for executive function is probably more than just a coincidence." That may be so, however, new scientific studies across several animal species, including humans, are challenging the notion that brain size alone is a measure of intelligence. Rather, scientists now argue, it is a brain's underlying organization and molecular activity at its synapses (the communication junctions between neurons through which nerve impulses pass) that dictate intelligence. Two years ago, Paul Manger, a professor of health sciences at the University of the Witwatersrand in Johannesburg, South Africa, caused quite a stir when he referred to the beloved bottlenose dolphin, owner of a large, nearly human-size brain, as "dumber than a goldfish." © 1996-2009 Scientific American Inc.

Keyword: Intelligence; Evolution
Link ID: 12757 - Posted: 06.24.2010

By Nathan Seppa A single episode of low blood sugar severe enough to require prompt medical attention increases a person’s risk of developing dementia in old age, a study in people with diabetes suggests. More than one bout of hypoglycemia seems to heighten the risk even further, researchers report in the April 15 Journal of the American Medical Association. While chronically high blood sugar is known to increase the risk of dementia and other health problems, less is understood about the long-term effects of periodic low blood sugar, says study coauthor Rachel Whitmer, an epidemiologist at the Kaiser Permanente Division of Research, in Oakland, Calif. She and her colleagues analyzed medical records from a Kaiser Permanente registry dating from 1980 to 2002 and identified nearly 17,000 people who had type 2 diabetes but no signs of dementia, mild cognitive impairment or even memory complaints during the time span. The people averaged 65 years of age as of 1994. The scientists noted any low blood sugar episodes that required a trip to a hospital or other emergency facility. For such treatment, Whitmer says, a patient would have gone beyond just being shaky and weak, as happens with mildly low blood sugar. “These were events where patients may have fainted or passed out or may have been unable to communicate with others — and were brought in,” she says. © Society for Science & the Public 2000 - 2009

Keyword: Alzheimers; Obesity
Link ID: 12756 - Posted: 06.24.2010

By Bryan Walsh Monday Medical science has deciphered many of the body's workings, down to the level of the gene, and isn't too far from using stem cells to repair its hobbled organs. But in many ways, the human body remains a vast and peculiar mystery. Take the common itch. Everyone knows from experience that a good scratch can cure an itch, but doctors still don't understand the physiological mechanism behind the itch-scratch connection. And that ignorance can have serious medical consequences. The common itch isn't so benign in many conditions, including shingles and AIDS, which can cause uncomfortably severe itching. Sometimes itching can occur inexplicably, without any apparent physical cause, and a patient's unchecked scratching can lead to excessive skin damage or worse. (Read "The Year in Medicine 2008: From A to Z.") But a study published today in the journal Nature Neuroscience offers some hope of lasting relief. A group of neuroscientists led by Glenn Giesler at the University of Minnesota, Minneapolis, hypothesized that the mechanism by which scratching relieves an itch takes place not along the nerve fibers of itchy skin but deep within the central nervous system — specifically, in the spinothalamic tract (STT) neurons in the spinal cord, which transmit information about pain, temperature and touch to the brain. (Previous studies have shown that STT neurons can be activated with the application of an itch-producing chemical like histamine and that the neurons send that itch sensation to the brain.) © 2009 Time Inc.

Keyword: Pain & Touch
Link ID: 12755 - Posted: 06.24.2010

A new drug which shows promise as a treatment for Alzheimer's disease has been developed by UK scientists. The Proceedings of the National Academy of Sciences reports the drug, CPHPC, removes a protein thought to play a key role in Alzheimer's from the blood. Tests at the University College London found the protein also disappeared from the brains of five Alzheimer's patients given the drug for three months. Longer and larger scale clinical studies are now being planned. The protein - serum amyloid P component (SAP) is always present in both the sticky clumps (plaques) and the tangles of nerve fibres that are found in the brains of people with Alzheimer's disease, and are thought to damage healthy cells. It appears to protect both structures from breaking up, and has also been shown - in lab experiments at least - to promote formation of the amyloid protein which forms the damaging plaques. There is also some evidence that SAP itself can damage brain cells directly. Two of the big potential advantages CPHPC are that it is not broken down once inside the body, and it has a very specific action, not interacting with cells at all, thus reducing the risk of side effects. The researchers expected a depletion of SAP in the five patients' blood - but were taken aback at the drug's apparent effect on the brain. By using laboratory tests they were also able to reveal both the molecular process underpinning the effect of the drug, and the way in which SAP accumulates in the brain in Alzheimer's disease. The study also confirmed that use of the drug - and the removal of SAP from the brain - had no side effects on the patients. CPHPC has already been given to patients with other diseases without any any adverse effects. (C)BBC

Keyword: Alzheimers
Link ID: 12754 - Posted: 04.14.2009

Does postpartum depression serve some evolutionary purpose? —Clint Johnson, Ridgecrest, Calif. Anthropologist Edward H. Hagen of Washington State University replies: Postpartum depression (PPD), which af­flicts 10 to 15 percent of new mothers, may have evolved as a strategic response to a lack of social support because it helped in passing on genes successfully. Many doc­tors believe PPD is triggered by the changes in a mother’s hormones after giving birth, yet studies have failed to find much evi­dence for a link between extreme hormone fluctuations and PPD. The fact that fathers, who do not experi­ence such changes, also suffer from PPD is strong evidence that it is not “just hormones.” The finding that PPD often plagues people who have marital problems or little outside support led biologists Randy Thornhill and F. Bryant Furlow of the University of New Mexico and me independently to propose that PPD has an evolved function. Many animals improve their chances of passing on their genes if they desert their young when food or parenting help is scarce and invest instead in future offspring that are more likely to survive and reproduce. This “parental investment theory” should apply especially well to humans. Human children are “expensive” to raise, requiring years of parenting before they can survive on their own. When a mother lacks support from the father or other family members, she may unconsciously conclude she cannot successfully raise her infant. The ensuing emotional pain from PPD operates somewhat like physical pain: stop what you’re doing—it’s harming your reproductive fitness! Studies confirm that mothers with PPD do significantly reduce parenting efforts and often have thoughts of harming their baby. © 1996-2009 Scientific American Inc.

Keyword: Depression; Evolution
Link ID: 12753 - Posted: 06.24.2010

By PERRI KLASS, M.D. Not long ago, in the clinic, a fellow pediatrician and mother asked whether we were still teaching our sons old-fashioned elevator etiquette: stand back and let the ladies off first. We all protested that we don’t particularly like it when men pull that elevator stunt — hospital elevators tend to be packed, and the best thing to do if you’re near the door is get out promptly — but we had to admit we thought our adolescent sons should know the drill. Once you start asking about whether there are special lessons that should be taught to boys, people jump pretty quickly from elevators to sex (or maybe that’s just the crowd I run with). Sex, after all, is a subject on which pediatricians give plenty of advice. And it becomes very tricky to formulate that advice without making some unpleasant assumptions about adolescent sexuality. It has never been easy for adults to deal with young teenagers honestly and sensibly on this subject, and it isn’t easy now. We live with an endless parade of hypersexualized images — and a constant soundtrack of adults lamenting children’s exposure to that endless parade. There’s increasing knowledge of dating violence, including well-publicized celebrity incidents. And there’s always a new movie to see about how adolescent boys are clueless, sex-obsessed goofballs. Copyright 2009 The New York Times Company

Keyword: Sexual Behavior; Aggression
Link ID: 12752 - Posted: 06.24.2010

By NICHOLAS BAKALAR In 1906, when Alois Alzheimer, a German psychiatrist, autopsied the brain of a 55-year-old woman, he saw under his microscope the characteristic amyloid plaques and neurofibrillary tangles of dementia. These were phenomena already well known, and Alzheimer never claimed to have discovered a new disease. Rather, he was presenting an unusual case of the ailment in a younger person, and he referred to it as “pre-senile dementia.” It was his colleague Emil Kraepelin who first called it Alzheimer’s disease in 1910, some say in an attempt to publicize the accomplishments of his academic department. In any case, there was widespread skepticism that Alzheimer had found anything new, and Kraepelin’s designation did not immediately stick. It was not until May 16, 1935, that The New York Times first printed the words “Alzheimer’s disease,” in an Associated Press dispatch. “Only about 100 cases of this particular kind of premature senility, which strikes between 40 and 60 years of age, have been reported,” it said. Alzheimer’s disease disappeared from the pages of The Times for the next three decades. In May 1968, in an article describing tests of a senility drug, Jane E. Brody distinguished between dementia and pre-senile dementia, but did not mention Alzheimer’s. Copyright 2009 The New York Times Company

Keyword: Alzheimers
Link ID: 12751 - Posted: 06.24.2010

By David Dobbs In 2006, soon after returning from military service in Ramadi, Iraq, during the bloodiest period of the war, Captain Matt Stevens of the Vermont National Guard began to have a problem with PTSD, or post-traumatic stress disorder. Stevens's problem was not that he had PTSD. It was that he began to have doubts about PTSD: the condition was real enough, but as a diagnosis he saw it being wildly, even dangerously, overextended. Stevens led the medics tending an armored brigade of 800 soldiers, and his team patched together GIs and Iraqi citizens almost every day. He saw horrific things. Once home, he said he had his share of "nights where I'd wake up and it would be clear I wasn't going to sleep again." He was not surprised: "I would expect people to have nightmares for a while when they came back." But as he kept track of his unit in the U.S., he saw troops greeted by both a larger culture and a medical culture especially in the Veterans Administration (VA) that seemed reflexively to view bad memories, nightmares and any other sign of distress as an indicator of PTSD. "Clinicians aren't separating the few who really have PTSD from those who are experiencing things like depression or anxiety or social and reintegration problems or who are just taking some time getting over it," Stevens says. He worries that many of these men and women are being pulled into a treatment and disability regime that will mire them in a self-fulfilling vision of a brain rewired, a psyche permanently haunted. © 1996-2009 Scientific American Inc.

Keyword: Stress
Link ID: 12750 - Posted: 06.24.2010

By DARCY HELLER STERNBERG I can spot Marty in a crowd a block away. He tilts left into the wind, as if he were shouldering the full blast of Hurricane Katrina, his arm gesticulating awkwardly. Once a well-dressed woman asked if I had seen “that man — I think he’s drunk.” I assured her the man was my husband. “He has Parkinson’s,” I told her. We get that a lot — snickers, whispers. Looks that wound. “When people stare,” Marty tells me, “I get nervous and shake that much more.” There are no rules of etiquette for dealing with a person who has a neurological disorder. Some people do stare; others recoil. Fortunately, though, many are genuine and forthcoming in their help. And that is as true here in New York City, supposedly the capital of heartless impatience, as it is anywhere in the country. Marty has to take a combination of seven drugs eight times a day. He bought an expensive pillbox specifically made for Parkinson’s patients; an alarm goes off when it’s time to take a pill. One problem: the container is so difficult to open that when he finally succeeds, the pill is likely to go flying across the room or, worse, into the street. Even when he’s able to grasp the pill and take it, it may not last as long as he would like. “After a few years of taking medication, people with Parkinson’s may begin to experience ‘wearing off’ spells,” Dr. Lawrence I. Golbe, a neurologist at Robert Wood Johnson University Hospital in New Brunswick, N.J., recently wrote in the Parkinson’s Disease Foundation newsletter, adding that for some patients the drugs may be effective for only three hours. Copyright 2009 The New York Times Company

Keyword: Parkinsons
Link ID: 12749 - Posted: 06.24.2010

by Paul Marks YOU are the victim of identity theft and the fraudster calls your bank to transfer money into their own account. But instead of asking them for your personal details, the bank assistant simply presses a button that causes the phone to produce a brief series of clicks in the fraudster's ear. A message immediately alerts the bank that the person is not who they are claiming to be, and the call is ended. Such a safeguard could one day be commonplace, if a new biometric technique designed to identify the person on the other end of a phone line proves successful. The concept relies on the fact that the ear not only senses sound but also makes noises of its own, albeit at a level only detectable by supersensitive microphones. If those noises prove unique to each individual, it could boost the security of call-centre and telephone-banking transactions and reduce the need for people to remember numerous identification codes. Stolen cellphones could also be rendered useless by programming them to disable themselves if they detect that the user of the phone is not the legitimate owner. Called otoacoustic emissions (OAEs), the ear-generated sounds emanate from within the spiral-shaped cochlea in the inner ear. They are thought to be produced by the motion of hair cells within the outer part of the cochlea. Typically, sounds entering the ear cause these outer hair cells to vibrate, and these vibrations are converted to electrical signals which are transmitted along the auditory nerve, allowing the sound to be sensed. Crucially, these cells also create their own sounds as they expand and contract. © Copyright Reed Business Information Ltd.

Keyword: Hearing
Link ID: 12748 - Posted: 06.24.2010

Failure to control type 2 diabetes may have a long-term impact on the brain, research has suggested. Severe hypoglycaemic episodes - hypos - occur when blood sugar levels drop dangerously low. A University of Edinburgh team found they may lead to poorer memory and diminished brain power. The study, based on 1,066 people with type 2 diabetes aged between 60 and 75, was presented at a conference of the charity Diabetes UK. The volunteers completed seven tests assessing mental abilities such as memory, logic and concentration. The 113 people who had previously experienced severe hypos scored lower than the rest of the group. They performed poorly in tests of their general mental ability, and vocabulary. There are at least 670,000 people in England aged between 60 and 75 years old who have Type 2 diabetes and around a third of them could be at risk of a hypo. Lead researcher Dr Jackie Price said: "Either hypos lead to cognitive decline, or cognitive decline makes it more difficult for people to manage their diabetes, which in turn causes more hypos. "A third explanation could be that a third unidentified factor is causing both the hypos and the cognitive decline. We are carrying out more research to establish which explanation is the most likely." Dr Iain Frame, director of research at Diabetes UK, said: "This study reinforces previous evidence which suggests that poorly controlled diabetes affects the functioning of the brain. "We already know that type 2 diabetes increases the risk of developing Alzheimer's disease, which is a type of dementia, and this research adds another piece to a very complex jigsaw puzzle. (C)BBC

Keyword: Learning & Memory; Obesity
Link ID: 12747 - Posted: 04.13.2009

Scientists say they understand more about how the body responds to pleasurable touch. A team, including scientists from the Unilever company, have identified a class of nerve fibres in the skin which specifically send pleasure messages. And people had to be stroked at a certain speed - 4-5cm per second - to activate the pleasure sensation. They say the study, published in Nature Neuroscience, could help understand how touch sustains human relationships. For many years, scientists have been trying to understand the mechanisms behind how the body experiences pain, and the nerves involved in conveying those messages to the brain. This is because people can suffer a great deal. Neuropathy, where the peripheral nervous system is damaged, can be very painful and sometimes the messaging system goes wrong a people feel pain even when there is no cause. But the researchers involved in this work were looking to understand the opposite sensation - pleasure. This research, which also involved experts at the University of Gothenburg in Sweden and at the University of North Carolina, recorded nerve responses in 20 people. They then tested how people responded to having their forearm skin stroked at a range of different speeds. They identified "C-tactile" nerve fibres as those stimulated when people said a touch had been pleasant. If the stroke was faster or slower than the optimum speed, the touch was not pleasurable and the nerve fibres were not activated. The scientists also discovered that the C-tactile nerve fibres are only present on hairy skin, and are not found on the hand. (C)BBC

Keyword: Pain & Touch
Link ID: 12746 - Posted: 04.13.2009

By LISA SANDERS, M.D. “I can’t see a doggone thing. It started off as a headache, and now I can’t see.” The middle-aged man’s face was flushed and shiny beneath a mop of prematurely white hair. His clear, blue eyes were shaded by a brow pulled together by worry. “I’d rather cut off my leg than lose my sight,” he told the slender, dark-haired doctor at his bedside. Three days ago he was at work at a local animal hospital when his head began to pound. “It was like there was someone inside my head trying to get out.” He made it to the end of the day, then went home and straight to bed. The headache was still there the next morning when he got up. He took his coffee and the Sunday newspaper to the living room and — as was his habit — turned to the obituaries. The page was a sea of gray. He couldn’t read it. He couldn’t even make out the headlines. He went to see his doctor, who sent him to an ophthalmologist. The ophthalmologist sent him to the emergency room. Hearing that his patient was being admitted to a hospital, the primary-care doctor promptly called Dr. Lydia Barakat, an infectious-disease specialist at Waterbury Hospital in Waterbury, Conn. The 58-year-old man had a high fever, he reported, and the thick optic nerves that connect the eyes to the brain were visibly swollen from some kind of increased pressure inside the skull. Barakat was worried. Infections in the brain carry a high risk of death and disability. “If you lose a nerve cell, it doesn’t come back,” she said. Infections involving the brain, she told me, were those most likely to keep her up at night. These were the infections where you couldn’t afford to miss anything. “If you’re not just a little scared when you see these patients, then you are either arrogant, indifferent or just plain ignorant.” Copyright 2009 The New York Times Company

Keyword: Vision
Link ID: 12745 - Posted: 06.24.2010

By Tina Hesman Saey Whether you like it or not, you’re a little different. If it makes you feel any better, so is everybody else. In fact, everybody is far more different than anybody had imagined. Scientists are only beginning to discover just how different humans are from each other at the genetic level and what those personal genetic attributes mean for health, history and the human evolutionary future. It’s true that people are 99.9 percent alike, if only minor spelling variations in the genetic instruction book are taken into account. In each person, about one in every 1,000 DNA bases — the chemical letters of the genetic alphabet — differs from the generic human construction and operating manual. So, on average, one person will differ from another at about 3 million of the 3 billion letters in the human genome. Researchers have recently mapped many of these single letter variations, called single 
nucleotide polymorphisms or SNPs, looking for variants that might play a role in complex diseases such as heart disease, diabetes and high blood pressure (SN: 6/21/08, p. 20). So far, SNPs have been associated with many diseases, but SNPs can also be protective. And those little spelling differences may contain information about a person’s geographic ancestry — just as whether people write color or colour is a clue about whether they hail from the United States or Great Britain. © Society for Science & the Public 2000 - 2009

Keyword: Genes & Behavior; Schizophrenia
Link ID: 12744 - Posted: 06.24.2010