By David Brown, Washington Post Staff Writer A team of Icelandic researchers has identified a gene that may play a part in up to one-fifth of the cases of Type 2 diabetes in the United States. The gene's function is not known for certain but it appears to play a role in the regulation of other genes involved in hormone secretion. The discovery was made by scientists at a Reykjavik company called DeCode Genetics Inc., which seeks the genetic underpinnings of disease using Iceland's population as a research tool. Iceland is a fruitful place for such work because the population is small and ethnically homogeneous, and has extremely good medical records. The findings were published online yesterday in the journal Nature Genetics. With diabetes, the body cannot adequately regulate glucose, its main fuel. In Type 1 diabetes, the body does not make enough insulin, the hormone that helps move sugar molecules from the bloodstream into cells. In Type 2 the body makes insulin, but cells resist its action. About 90 percent of diabetes cases are Type 2, with overweight people at increased risk. © 2006 The Washington Post Company

Keyword: Genes & Behavior; Obesity
Link ID: 8396 - Posted: 06.24.2010

From a simple trick to a simply stunning feat, magic captivates us. But scientists are starting to pull the curtain back on how magicians dupe us with sleight of hand tricks. Turns out, it's not our eyes that buy in to sleight of hand tricks, but our brain's parietal cortex — the region that helps us focus. Because magicians know how to keep it occupied our eyes can fail to notice dramatic visual changes, says Nilli Lavie, a professor of psychology and brain sciences at University College London in the United Kingdom. "A magician will load your eye by [performing] a dramatic act, including hand waving," she says. "And as you're focusing say on the magician's left hand you'll fail to notice the magical trick that's occurring with the right hand." Such David Copperfield-like deceptions induce what psychologists call change blindness, a phenomenon where people fail to notice dramatic changes because their attention is being held elsewhere. To test change blindness, Lavie used a classic attention test called the face test. As faces flash in succession and change onscreen, volunteers press a key to indicate when they see a change. © ScienCentral, 2000-2006.

Keyword: Vision; Attention
Link ID: 8395 - Posted: 06.24.2010

Susan Milius No insult intended to human teachers, but a research team in England says that the first clear demonstration of true teaching among other animals comes from a species without much of a brain—an ant. A variety of animals do things that onlookers learn to copy, but biologists have a stricter definition for true teaching, explains Nigel R. Franks of the University of Bristol in England. First, teachers do a task less efficiently than they would outside the classroom. Second, pupils of a true teacher learn faster than they would by themselves. Franks and his Bristol colleague Tom Richardson added another requirement: feedback between teacher and student. The tiny ant, Temnothorax albipennis, from England's southern coast, meets the criteria, Franks and Richardson report in the Jan. 12 Nature. In lab tests, the species' teachers guided nest mates to a food source (To see a video of this behavior, click here). "One would have expected to see teaching in chimpanzees or [some other primate], but for the first fairly strong evidence of it to come from ants is surprising and interesting," says Bennett G. Galef Jr. of McMaster University in Hamilton, Ontario. Last year, Galef and his colleagues reported that mother rats didn't teach their young to tell good food from bad in a lab test. Copyright © 2006 Science Service.

Keyword: Learning & Memory; Evolution
Link ID: 8394 - Posted: 06.24.2010

A team of scientists at the Weizmann Institute of Science, led by Prof. Michal Schwartz of the Neurobiology Department, has come up with new findings that may have implications in delaying and slowing down cognitive deterioration in old age. The basis for these developments is Schwartz's team's observations, published today in the February issue of Nature Neuroscience, that immune cells contribute to maintaining the brain's ability to maintain cognitive ability and cell renewal throughout life. Until quite recently, it was generally believed that each individual is born with a fixed number of nerve cells in the brain, and that these cells gradually degenerate and die during the person's lifetime and cannot be replaced. This theory was disproved when researchers discovered that certain regions of the adult brain do in fact retain their ability to support and promote cell renewal (neurogenesis) throughout life, especially under conditions of mental stimuli and physical activity. One such brain region is the hippocampus, which subserves certain memory functions. But how the body delivers the message instructing the brain to step up its formation of new cells is yet unknown. The central nervous system (CNS), comprising the brain and spinal cord, has been considered for a long time as "a forbidden city", in which the immune system is denied entry as its activity is perceived as a possible threat to the complex and dynamic nerve cell networks. Furthermore, immune cells that recognize the brain's own components("autoimmune" cells) are viewed as a real danger as they can induce autoimmune diseases.

Keyword: Neuroimmunology
Link ID: 8393 - Posted: 01.16.2006

A collaboration, led by Sydney scientists at the Garvan Institute of Medical Research and University of New South Wales, has discovered the first risk gene specifically for bipolar disorder, also known as manic-depressive illness. This means that people who have a particular form of this gene are twice as likely to develop the disease. Dr Ian Blair, lead author of the research paper published in Molecular Psychiatry, says: “We are the first group in the world to take a multi-faceted approach to identify a bipolar risk gene - we used a number of families, unrelated patients, and therapeutic drug mouse models. Each of these three lines of investigation led us to a gene called FAT.” “We know that the FAT gene codes for a protein that is involved in connecting brain cells together, what we need to do now is find out exactly how the it contributes to the increased risk of bipolar disorder,” explains Dr Blair. Bipolar disorder is a major psychiatric illness affecting around one person in every 50. Tragically, around one in six people suffering from the condition will commit suicide. Mood-stabilising medications are typically prescribed to help control bipolar disorder. Lithium was the first mood-stabilising medication approved by the U.S. Food and Drug Administration (FDA) for treatment of mania. For decades it has been widely prescribed for the treatment bipolar disorder, yet no one knows for sure why it works.

Keyword: Schizophrenia; Genes & Behavior
Link ID: 8392 - Posted: 06.24.2010

In fruit flies, pathway differentiates between remembering for an hour or for a day Harvard University biologists have identified a molecular pathway active in neurons that interacts with RNA to regulate the formation of long-term memory in fruit flies. The same pathway is also found at mammalian synapses, and could eventually present a target for new therapeutics to treat human memory loss. The findings will be presented this week on the web site of the journal Cell. Even for a fruit fly, learning and memory are important adaptive tools that facilitate survival in the environment. A fly can learn to avoid what may do it harm, such as a flyswatter, or in the laboratory, an electric shock that happens when it smells a certain odor. "It has been known for some time that learning and long-term memory require synthesis of new proteins, but exactly how protein synthesis activity relates to memory creation and storage has not been clear," says Sam Kunes, professor of molecular and cellular biology in Harvard's Faculty of Arts and Sciences. "We have been able to monitor, for the first time, the synthesis of protein at the synapses between neurons as an animal learns, and we found a biochemical pathway that determines if and where this protein synthesis happens. This pathway, called RISC, interacts with RNA at synapses to facilitate the protein synthesis associated with forming a stable memory. In fruit flies, at least, this process makes the difference between remembering something for an hour and remembering it for a day or more."

Keyword: Learning & Memory
Link ID: 8391 - Posted: 01.13.2006

Just as a pocket watch requires a complex system of gears and springs to keep it ticking precisely, individual cells have a network of proteins and genes that maintain their own internal clock -- a 24-hour rhythm that, in humans, regulates metabolism, cell division, and hormone production, as well as the wake-sleep cycle. Studying this "circadian" rhythm in fruit flies, which have genes that are similar to our own, scientists have constructed a basic model of how the cellular timekeeper works. But now, a new report in this week's issue of the journal Science turns the old model on its head: By providing a glimpse into living cells, Rockefeller University researchers have uncovered a previously undetected clock inside the circadian clock. The scientists made the finding with a rarely used technique called FRET, which enabled them to follow circadian proteins over an extended period of time and watch the clock as it ticks away in a living cell. At the most basic level, an organism's sleep-wake rhythms are governed by 10 known genes. In the fly, two of those genes -- period and timeless -- produce proteins that fluctuate in a negative feedback loop that takes about 24 hours to complete. At night, two other genes (clock and cycle) stimulate production of Period and Timeless proteins, which begin to accumulate in the cell's cytoplasm. After about six hours, the two proteins move into the nucleus; their presence turns off the genes, which then remain inactive until Period and Timeless degrade and the whole cycle begins anew.

Keyword: Biological Rhythms
Link ID: 8390 - Posted: 01.13.2006

Recent research has revealed that brains continue to produce new neurons throughout life, helping create new neural networks. This neurogenesis only takes place in a few specific areas, such as the area in which the brain and spinal column meet. The new cells, however, can migrate throughout the brain and turn up as far away as the olfactory bulb--a cluster of nerve cells at the front surface of the brain responsible for the sense of smell. A recent study in mice has revealed that these neurons make the long and complicated journey by going with the flow of spinal fluid circulating in the brain. Neurologist Kazunobu Sawamoto at Keio University in Japan and an international team of his colleagues used fluorescent dye and India ink to trace the flow of spinal fluid in mice and found that it followed the whiplike waving of hairlike projections known as cilia from cells lining the route. They then tracked neurons as they migrated from region to region of the brain and found that new neurons oriented in the direction of fluid flow rather than the direction of their ultimate destination in the olfactory bulb. © 1996-2006 Scientific American, Inc.

Keyword: Neurogenesis; Development of the Brain
Link ID: 8389 - Posted: 06.24.2010

For some people sweets offer a treat or a little pick-me-up. "It boosts my mood, makes me a little happier and then I can get through my day," says Leanne Mercadante a student in New York. "I feel happy, a little more relaxed." For others it's more of an obsession. "It's just comfortable, just total comfort food," explains Mika De Young, a self-confessed chocoholic. "It makes you happy." "People that are stressed out, have any kind of anxiety, will definitely look to candy for relief," explains Kris Minkstein who meets many a sweet-lover while working at Dylan's Candy Bar in New York City. "When, a lot of times, a customer's had a long day… they'll pretty much indulge. They'll buy a lot of candy." To those of us with our hands in the candy jar, here's some sweet news. Scientists have now shown that sugar can calm the nerves, at least in rats. As reported on ScientificAmerican.com, brain researchers studied rats that were given water sweetened with sucrose — another name for sugar — twice a day for two weeks, as part of their regular nutritionally balanced diet, and compared them to rats that were not. © ScienCentral, 2000-2006.

Keyword: Obesity; Stress
Link ID: 8388 - Posted: 06.24.2010

The paper referred to is ‘Non-Advertized does not Mean Concealed: Body Odour Changes across the Human Menstrual Cycle’, Jan Havlíček, Radka Dvořáková, Luděk Bartoš and Jaroslav Flegr, Ethology, 112:1, page 81 - January 2006. To view the article in full, visit www.blackwell-synergy.com and Login/Register for free. Click on the My Synergy tab at the top of the screen and then on the blue Access tab. On the next screen type in the access token: ETHJan06 and click Continue. This will activate your free online access to Ethology. The Access Token is valid for 30 days. Next time you want to view the article, Login at Blackwell Synergy, click on the My Synergy tab and a hyperlink to the journal will be listed. For further information about this press release please contact: Jan Havlíček, Charles university in Prague, email address Jan.Havlicek@fhs.cuni.cz Ethology publishes original contributions from all branches of behavioural research on all species of animals, both in the field and lab. It contains scientific articles of general interest in English language that are based on a theoretical framework. A section on "Current issues - perspectives and reviews" is included as well as theoretical investigations, essays on controversial topics and reviews of notable books. Further details of the journal are available at www.blackwellpublishing.com/eth

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 8387 - Posted: 06.24.2010

A gene involved in causing bipolar disorder in as many as 10% of patients with the condition has been identified by researchers in Australia. Other teams have previously claimed to have found bipolar susceptibility genes, but this is the first time that the evidence has been close to conclusive, the researchers claim. The work might also explain how lithium, which has been prescribed for bipolar sufferers for more than 30 years, can help patients. But while lithium works for some, one-third to one-half of patients do not benefit from existing treatments – none of which were created specifically for the disorder, which is characterised by extreme mood states. “The long term goal is to get new drug targets that are specific for bipolar disorder,” says team member Ian Blair of the Garvan Institute of Medical Research in Sydney. The new study of about 1200 patients from Australia, the UK and Bulgaria implicates a gene called Fat on chromosome four. This gene plays a role in cell adhesion in the brain. People with the newly identified polymorphism, or form of this gene, appear to be at twice the risk of developing bipolar disorder, though it is not yet clear exactly why, says Blair. © Copyright Reed Business Information Ltd.

Keyword: Schizophrenia
Link ID: 8386 - Posted: 06.24.2010

Violent computer games may make people more likely to act aggressively, a study says. Previous research has found people who play such games are more likely to be aggressive but some say this just shows violent people gravitate towards them. But a team from the University of Missouri-Columbia said their study which monitored the brain activity of 39 game players suggests a causal link. The findings were published on the New Scientist website. The researchers measured a type of brain activity called the P300 response which reflects the emotional impact of an image. When shown images of real-life violence, people who played violent video games were found to have a diminished response. However, when the same group were shown other disturbing images such as dead animals or ill children they had a much more natural response. When the game players were given the opportunity to punish a pretend opponent those with the greatest reduction in P300 meted out the severest punishments. Psychologist Bruce Bartholow, the lead researcher of the study which will be published in full in the Journal of Experimental Social Psychology later this year, said: "As far as I'm aware, this is the first study to show that exposure to violent games has effects on the brain that predict aggressive behaviour. (C)BBC

Keyword: Aggression
Link ID: 8385 - Posted: 01.12.2006

By Stacy Weiner If you and your partner sleep apart, you may be lonely, but you're not alone. According to a 2005 National Sleep Foundation survey, 23 percent of partnered adults frequently sleep solo because of their loved one's snoring, kicking or other sleep problem. That number doesn't include those who bed down apart because of mismatched schedules or desire for different room temperatures, or to let an exhausted spouse avoid a tyke's wake-up calls. And though a small number of couples who opt for separate beds do so to recapture a sense of romance, for most, there's one simple fantasy: some decent rest. In fact, according to the National Sleep Foundation survey of 1,506 adults, disruptive bedmates rob their partners, on average, of 49 minutes of shut-eye each night. Kensington mom Naomi Rivkis has regularly slept apart from her husband throughout their seven-year marriage. As is the case for many spouses, it's her mate's snoring that sends Rivkis scrambling for quieter ground; more than half of snorers report having disturbed someone's sleep. Most of the time Rivkis uses earplugs, but two or three nights a week she needs a break from the uncomfortable contraptions. At first, the 36-year-old said she barely noticed the separation because her husband was in law school and often chose books over bed anyway. Now that sleeping apart is a set pattern, though, she remains unfazed, especially since the couple resolves all conflicts before bedtime. "I don't want it to look to us even slightly like sleeping apart is associated with there being anything wrong," she said. "As long as that's separated out, it's just a physical convenience." © 2006 The Washington Post Company

Keyword: Sleep
Link ID: 8384 - Posted: 06.24.2010

By JANE E. BRODY Patients with debilitating pain from chronic illness, accidents, surgery or advanced cancer have long had problems getting adequate medication to control their pain and make life worth living. Now the federal government, and especially the Drug Enforcement Administration, is working overtime to make it even harder for doctors to manage serious pain, including that of dying patients trying to exit this world gracefully. In an article in the current New England Journal of Medicine titled "The Big Chill: Inserting the D.E.A. into End-of-Life Care," two specialists in palliative care, Dr. Timothy E. Quill and Dr. Diane E. Meier, state that despite some physicians' commitment to treat pain and despite the effectiveness of opioid drugs like OxyContin and morphine, "abundant evidence suggests that patients' fears of undertreatment of distressing symptoms are justified." They continue, "Although a lack of proper training and overblown fears of addiction contribute to such undertreatment, physicians' fears of regulatory oversight and disciplinary action remain a central stumbling block." Copyright 2006 The New York Times Company

Keyword: Pain & Touch; Drug Abuse
Link ID: 8383 - Posted: 01.12.2006

Environmental and genetic factors lead to neural tube defects in 1 in every 1,000 births and cause 1 in 20 of every spontaneous abortion. One cause of these defects is the failure of cells within the neural tube to migrate to the middle of the developing neural tube. A study in this week's issue of Nature is the first to report on the molecular mechanism that directs cells to migrate to the correct local within the developing neural tube of vertebrates. Marek Mlodzik, PhD, Professor, Molecular, Cell and Development Biology at Mount Sinai School of Medicine has previously reported that the asymmetrical distribution of specific proteins within neural tissues in fruit flies controls the orientation and migration of cells. Dr. Mlodzik's and Dr. Schier's laboratories have now found that a similar mechanism is at work in vertebrates. During cell division the polarity of a cell is lost. Therefore, the newly formed daughter cells initially lack the information to direct them to migrate to the midline where they are needed for proper neural tube development. The report in Nature is the first to demonstrate that the polarity is restored to the daughter cells after rather than during cell division and to provide the specific molecules involved in restoring polarity.

Keyword: Development of the Brain
Link ID: 8382 - Posted: 01.12.2006

An international team of researchers, led by investigators at Washington University School of Medicine in St. Louis, are zeroing in on a gene that increases risk for Alzheimer's disease. They have identified a region of chromosome 10 that appears to be involved in risk for the disease that currently affects an estimated 4.5 million Americans. "There are a few genes that have been implicated in the development of early-onset Alzheimer's disease, but other than APOE, no genes have been found that increase risk for the more common, late-onset form of the disease," says principal investigator Alison M. Goate, D. Phil., the Samuel and Mae S. Ludwig Professor of Genetics in Psychiatry at Washington University. "The region of DNA identified in our study showed evidence of replication in four independent series of experiments. I haven't seen a putative risk factor show such consistent results since the e4 variant of the APOE gene was identified as a risk factor for late-onset Alzheimer's disease more than 10 years ago." In the January issue of the American Journal of Human Genetics, Goate's team of researchers reports results of a scan of more than 1,400 single-nucleotide polymorphisms (SNPs) on chromosome 10 to home in on susceptibility genes for late-onset Alzheimer's disease.

Keyword: Alzheimers; Genes & Behavior
Link ID: 8381 - Posted: 01.12.2006

Animals do not need a big brain to be able to teach each other, a new study suggests. Animal behaviourists in the UK believe they have found the first evidence of two-way teacher-pupil communication between ants, suggesting that teaching behaviour may have evolved according to the value of information rather than brain size. Some ants use tandem running when foraging. This is when one ant appears to lead another from the nest to a food source by using signals that control the speed and route of the journey. Nigel Franks and Tom Richardson at Bristol University examined tandem running in Temnothorax albipennis ants to see if this was an example of teaching with feedback going from teacher to pupil and vice-versa. The leader’s speed is controlled by frequent taps on its legs and abdomen by the antennae of the follower ant – who appears to stop frequently to learn the route back. Teaching differs from simply broadcasting information in that the teacher must modify their behaviour, at some cost, to assist a naďve observer to learn more quickly. © Copyright Reed Business Information Ltd.

Keyword: Learning & Memory; Evolution
Link ID: 8380 - Posted: 06.24.2010

By Ranit Mishori One afternoon in 1999, Denise Portis's son Christopher fell and hurt himself badly. But Portis didn't answer his cries. The reason: She couldn't hear him. Since age 27, she'd been living with a profound and progressive hearing loss, its cause unknown. She thought she'd adapted. Then the incident with Christopher "shook my world," the Frederick woman recalls. She already was using two hearing aids, but she knew she needed something else. A while later, she got it: a cochlear implant -- a needle-sized electrode surgically placed under the skin at the base of the skull, behind the ear. Last July, several congressmen and guests of the Congressional Hearing Health Caucus watched a video of the results. As a technician switches on the device, amazement lights up Portis's face. Then Christopher, now 14, said, "Hi, Mom." Portis, 39, bursts into tears. "The last time I really heard him clearly," she recalled later, "he was in kindergarten and he still had a little-boy voice." Growing numbers of Americans appear to be joining Portis in opting for the "bionic solution" to hearing loss. Med-El, one of three leading implant manufacturers, estimates market growth at 15 to 20 percent a year. According to the Food and Drug Administration (FDA), approximately 13,000 adults and 10,000 children had received implants as of 2002, the last year for which data are available. © 2006 The Washington Post Company

Keyword: Hearing
Link ID: 8379 - Posted: 06.24.2010

By SANDRA BLAKESLEE On a hot summer day 15 years ago in Parma, Italy, a monkey sat in a special laboratory chair waiting for researchers to return from lunch. Thin wires had been implanted in the region of its brain involved in planning and carrying out movements. Every time the monkey grasped and moved an object, some cells in that brain region would fire, and a monitor would register a sound: brrrrrip, brrrrrip, brrrrrip. A graduate student entered the lab with an ice cream cone in his hand. The monkey stared at him. Then, something amazing happened: when the student raised the cone to his lips, the monitor sounded - brrrrrip, brrrrrip, brrrrrip - even though the monkey had not moved but had simply observed the student grasping the cone and moving it to his mouth. The researchers, led by Giacomo Rizzolatti, a neuroscientist at the University of Parma, had earlier noticed the same strange phenomenon with peanuts. The same brain cells fired when the monkey watched humans or other monkeys bring peanuts to their mouths as when the monkey itself brought a peanut to its mouth. Later, the scientists found cells that fired when the monkey broke open a peanut or heard someone break a peanut. The same thing happened with bananas, raisins and all kinds of other objects. Copyright 2006 The New York Times Company

Keyword: Vision
Link ID: 8378 - Posted: 01.11.2006

Mild cognitive impairment (MCI), a transitional stage between normal cognition and Alzheimer's disease, exists in two different forms, according to a study published today by researchers from the University of Pittsburgh School of Medicine and the University of California, Los Angeles in the Archives of Neurology. Using a new imaging procedure that creates 3-D maps of the brain, researchers determined specific areas that had degenerated in people with MCI. Depending on the person's symptoms, more tissue was lost in the hippocampus, a brain area critical for memory and one of the earliest to change in Alzheimer's disease, indicating two different paths of progression to Alzheimer's disease. The finding could lead to better diagnosis and treatment of patients with MCI, perhaps delaying or preventing the onset of dementia. MCI is categorized into two sub-types – currently distinguished based solely on symptoms. Those with MCI, amnesic subtype (MCI-A) have memory impairments only, while those with MCI, multiple cognitive domain subtype (MCI-MCD) have other types of mild impairments, such as in judgment or language, but also have either mild or no memory loss. Both sub-types progress to Alzheimer's disease at the same rate. Until now it was not known if the pathologies of the two types of MCI were different, or if MCI-MCD was just a more advanced form of MCI-A. Researchers found that the hippocampus of the patients with MCI-A was 14 percent smaller than that of the healthy subjects, nearly as great as the 23 percent shrinkage seen in Alzheimer's disease. But, the hippocampus of those with MCI-MCD most resembled that of the controls, showing only 5 percent shrinkage.

Keyword: Alzheimers
Link ID: 8377 - Posted: 06.24.2010