Genes that control the size and complexity of the brain have undergone much more rapid evolution in humans than in non-human primates or other mammals, according to a new study by Howard Hughes Medical Institute researchers. The accelerated evolution of these genes in the human lineage was apparently driven by strong selection. In the ancestors of humans, having bigger and more complex brains appears to have carried a particularly large advantage, much more so than for other mammals. These traits allowed individuals with “better brains” to leave behind more descendants. As a result, genetic mutations that produced bigger and more complex brains spread in the population very quickly. This led ultimately to a dramatic “speeding up” of evolution in genes controlling brain size and complexity. “People in many fields, including evolutionary biology, anthropology and sociology, have long debated whether the evolution of the human brain was a special event,” said senior author Bruce Lahn of the Howard Hughes Medical Institute at the University of Chicago. “I believe that our study settles this question by showing that it was.” Lahn and his colleagues reported their data in a research article published in the December 29, 2004, issue of the journal Cell. © 2004 Howard Hughes Medical Institute.

Keyword: Evolution; Genes & Behavior
Link ID: 6625 - Posted: 06.24.2010

BERKELEY – Immersed as we are in a sea of smells, how is it we're not continually overwhelmed with fair or foul odors until we actively inhale a rose or sniff the milk for a hint of sourness? University of California, Berkeley, neuroscientists have scanned the brains of people sniffing odors and found an answer. A composite fMRI scan of the brains of 10 subjects undergoing random sniffing trials, where left is the left side of the brain. The piriform cortex is lit up with activity. The temporal (outer) portion of the cortex processes odors and is active whether or not we are paying attention to the smells around us. The frontal (inner) portion and tubercle are most active when we pay attention to the odors. (Christina Zelano, Noam Sobel/UC Berkeley) It turns out that the brain is detecting and processing all the odors around us, but a particular area of the brain actively tunes this out unless the odor reaches a high level, such as when we walk into a cloud of cloying perfume or step in dog poop. When we want to sniff for odors, however, the brain releases the block and begins to pay attention to the smells around us. It even tunes in very precisely to specific smells, allowing us, for instance, to search for a hint of blackberry in a glass of zinfandel. Copyright UC Regents

Keyword: Chemical Senses (Smell & Taste)
Link ID: 6624 - Posted: 06.24.2010

Children who dance are more at risk of having eating disorders like anorexia when they grow up, research has found. It is believed to be the first time a link has been found with dancing for pleasure as a child and such problems. The researchers said the study suggests "participation in dance as a young girl has a long term effect on a woman's eating behaviour". The study, by psychiatrists at the University of Minnesota, is published in the Journal of Sleep Research. Previous studies have found eating disorders are more common in professional ballet dancers, as well as elite athletes. Eating disorders are a serious problem in the UK. It is estimated that at least 165,000 people, mostly women, are affected and that one in 10 will die as a result of their condition. Both anorexia, which involves starving the body of food and bulimia, a cycle of starving and bingeing, are closely linked to mental illness. They now account for more deaths among psychiatric patients than anything else. Media images of super thin models and pop stars are thought to be a major influence on youngsters' eating habits. The desire for a perfect body can mean some lose control of their eating habits and become preoccupied with their appearance. To see if there was any connection between childhood dance and adult eating, researchers recruited 546 women aged from 17 to 55. Each one was quizzed on whether they had danced in childhood. They also completed special questionnaires designed to measure disordered eating behaviours, body image and signs of depression. Just under two-thirds of the women said they had danced when they were children. (C)BBC

Keyword: Anorexia & Bulimia
Link ID: 6623 - Posted: 12.26.2004

Self-knowledge is difficult, as Socrates and virtually every philosopher since Socrates has pointed out. Of all the subjects into which human beings have chosen to inquire, the most resistant to understanding has turned out to be human beings themselves. Indeed, that we researchers have turned out to be our own most recalcitrant subjects must surely constitute one of the leading ironies of post-Enlightenment thought. Human beings just don't seem to fit very well into the scientific picture we have developed of our world. It is hard to comprehend how a universe governed by physical laws could give rise to or contain beings that are conscious, make free decisions, suffer and love -- or, for that matter, beings that are capable of being puzzled at the existence of such beings. Considered as bodies, we are fairly easy to understand. Bodies are just collections of atoms, and seem to behave, more or less, as collections of atoms ought to behave -- putting aside, again, the fact that these bodies happen to be conscious and autonomous and that they think and feel. But these aspects -- the ones connected, in the traditional way of categorizing matters, not so much with our bodies as with our minds -- cannot, of course, be put aside. They are not only the most troublesome features of humans but, for us humans, the most essential. "One agreeable feature of writing about the mind is that it is not necessary to explain why the subject is important," John Searle writes in his new book, "Mind: A Brief Introduction.'' "The operation of the mind -- conscious and unconscious, free and unfree, in perception, action, and thought, in feeling, emotions, reflection, and memory, and in all its other features - - is not so much an aspect of our lives, but in a sense, it is our life." ©2004 San Francisco Chronicle

Keyword: Miscellaneous
Link ID: 6622 - Posted: 06.24.2010

Packing on pounds in huge numbers is a world populace no longer limited to plumped up Americans. The phenomenon is so severe it prompted the World Health Organization to coin a new term —globesity. What's eating those joining the epidemic? Researchers say a multitude of factors, including the possibility that one powerful hunger hormone seems to go haywire in heavy people. Julio Licinio, a pharmacogeneric researcher at UCLA School of Medicine, reported on the importance of this naturally occurring hormone—ghrelin. Licinio collected blood samples every seven minutes, over a 24 hour period, from five obese men and five lean men, then measured their levels of leptin, adiponectin and ghrelin, all hormones known to contribute to appetite regulation and weight gain and loss. Ghrelin, an appetite stimulant created when the stomach and small intestines secrete specialized cells, is the first natural appetite stimulant known to originate from outside the brain, making it a target of interest for researchers trying to manipulate weight. In Licinio's study, ghrelin registered wildly different levels of activity at different times in each subject group, surprising his research team. "When we looked at the data from the obese subjects, we saw that they had the same breakfast, lunch and dinner increases, but at night the levels were flat," he explains. "So, the way we interpreted these results is that we think that obese people in a sense are more sensitive to the hormone during the day and they don't make much of it at night. And in the lean people, they make more of it at night and…they sleep through their cravings.…so they're protected from overeating." © ScienCentral, 2000- 2004

Keyword: Obesity
Link ID: 6621 - Posted: 06.24.2010

St. Louis, -- Researchers knew that prions, the misfolded proteins that cause mad cow disease and other brain disorders, were killing off a class of important brain cells in a transgenic mouse model. But when they found a way to rescue those cells, they were astonished to discover the mice still became sick. Now they believe previous efforts to find the beginnings of the mouse disorder may have been focused on the wrong part of the brain cell and are plotting new directions for research. In a study that appears in the Jan. 1 issue of the Proceedings of the National Academy of Sciences, scientists report evidence that clinical symptoms in the mice are produced by damage to synapses, the areas where nerve cell branches come together for communication. "This could have important therapeutic implications," says senior author David Harris, M.D, Ph.D, professor of cell biology and physiology at Washington University School of Medicine in St. Louis. "There's a great deal of effort being put into developing treatments for neurodegenerative disorders that would inhibit neuron death. Our results suggest that if we just prevent cell death without doing something to maintain the functionality of the synapse, patients may still get sick."

Keyword: Prions; Apoptosis
Link ID: 6620 - Posted: 12.26.2004

SYDNEY, AUSTRALIA: Fit, well-fed male field crickets die young because they spend too much time courting members of the opposite sex, according to research by Australian scientists in the latest edition of Nature. The results reveal how male crickets (Teleogryllus commodus) fed on a high protein diet engaged in more "sexual calling" and died sooner than males reared on a low protein diet. The well-fed males also died earlier than well-fed female crickets (females don't "call" to males). The scientists manipulated the crickets' dietary intake by feeding high, medium and low protein diets to three different groups. "The high protein fed male crickets spent the extra capital that they got from a better diet on mating behaviour, which shortened their longevity," says Dr Luc Bussiere, a UNSW postdoctoral research fellow and co-author to the study. "So it's obvious that for these crickets, a long life isn't all it's cracked up to be." "Supporting the idea that well-fed crickets reduced longevity was a consequence of heightened sexual display ("calling)" was the finding that males raised on both high and medium protein diets lost a greater proportion of their body weight after each night's "calling" than those fed on a low protein diet," says UNSW's Dr John Hunt, an ARC postdoctoral research fellow.

Keyword: Sexual Behavior
Link ID: 6619 - Posted: 12.26.2004

(Kingston, ON) – Birds that migrate early in the season may have a distinct advantage when it comes to attracting the opposite sex, say researchers from Queen's University and the Smithsonian Institution. And it's all about the feathers. Researchers were surprised to discover that the timing of a male songbird's reproduction cycle affects the colour of his feathers and may have important implications for his success in attracting mates. When migratory songbirds raise their young extremely late in the summer, many don't have time to molt (shed their feathers and replace with new growth) before heading south, the new study shows. "This means they must molt at stopover sites on their journey to tropical winter habitats," explains Ryan Norris, who conducted the research as part of his PhD in biology at Queen's, supervised by Professors Laurene Ratcliffe (Queen's Biology) and Peter Marra (Smithsonian Environmental Research Center). "Their replacement feathers, grown en route, are less colourful than those of birds that had time to molt before migration, which may put them at a disadvantage in attracting females the following breeding season," says Dr. Norris. "Both findings – that molting in some songbirds occurs after migration has begun, and that their new feathers are duller in colour – were surprising."

Keyword: Sexual Behavior
Link ID: 6618 - Posted: 06.24.2010

BOSTON- Researchers at Dana-Farber Cancer Institute have compiled the first atlas showing the locations of crucial gene regulators, or switches that determine how different parts of the brain develop – and, in some cases, develop abnormally or malfunction. The scientists say the map will accelerate research on brain tumors and neurological diseases that result from mutations in these switch genes – called "transcription factors." When these genes are altered, the genes they control can go awry, causing abnormalities in the development or function of nerves and related structures. Although the gene regulators were pinpointed using mouse brains, the map applies to the human brain as well. "This is the first systematic mapping of all of the major brain areas that shows what regulatory genes are expressed in those specific locations," said Quifu Ma, PhD, of Dana-Farber's Cancer Biology Department. He is senior author of a paper appearing in today's online issue of the journal Science, along with Charles D. Stiles, PhD, also of Dana-Farber. Transcription factors are genes that control the expression, or activity, of "target" genes. These factors play a pivotal role in brain development by direction the formation of neurons and supporting cells called glia from uncommitted progenitor cells. Until now, brain transcription factors had not been systematically isolated and their locations within different parts of the brain pinned down.

Keyword: Genes & Behavior
Link ID: 6617 - Posted: 06.24.2010

Scientists have discovered that a system in our brain which responds to actions we are watching, such as a dancer's delicate pirouette or a masterful martial arts move, reacts differently if we are also skilled at doing the move. The University College London (UCL) study, published in the latest online edition of Cerebral Cortex, may help in the rehabilitation of people whose motor skills are damaged by stroke, and suggests that athletes and dancers could continue to mentally train while they are physically injured. In the UCL study, dancers from the Royal Ballet and experts in capoeira - a Brazilian martial arts form - were asked to watch videos of ballet and capoeira movements being performed while their brain activity was measured in a MRI scanner. The same videos were shown to normal volunteers while their brains were scanned. The UCL team found greater activity in areas of the brain collectively known as the 'mirror system' when the experts viewed movements that they had been trained to perform compared to movements they had not. The same areas in non-expert volunteers brains didn't care what dance style they saw.

Keyword: Miscellaneous
Link ID: 6616 - Posted: 12.26.2004

Sudden cardiac death from emotional stress may be triggered by uneven signals from the brain to the heart, according to a study by University College London (UCL) scientists published in the January issue of Brain . UCL researchers have discovered that a system which normally coordinates signalling from the brain to different parts of the heart may be disrupted in some people, making them vulnerable to potentially fatal abnormal heart rhythms during mentally taxing tasks or emotional events such as family gatherings. This is particularly true of people who already have heart disease, but it is the brain that may be most responsible. The new study suggests that uneven brain activity, in a region where nerves link directly to the heart, seems to result in an uneven distribution of signals across the heart, which stops the heart from contracting normally. Around a third of the 300,000 sudden cardiac deaths which occur each year in the US arise from a blood clot in a major artery, which leads to a fatal heart attack. Mental stress is thought to be responsible for a further 20 per cent of these deaths, but scientists have been baffled by the exact mechanisms by which stress can bring on a fatal short-circuiting of the heart. Copyright © 1999-2004 UCL

Keyword: Epilepsy
Link ID: 6615 - Posted: 06.24.2010

Acupuncture provides pain relief and improves function for people with osteoarthritis of the knee and serves as an effective complement to standard care. This landmark study was funded by the National Center for Complementary and Alternative Medicine (NCCAM) and the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), both components of the National Institutes of Health. The findings of the study — the longest and largest randomized, controlled phase III clinical trial of acupuncture ever conducted — were published in the December 21, 2004, issue of the Annals of Internal Medicine *. The multi-site study team, including rheumatologists and licensed acupuncturists, enrolled 570 patients, aged 50 or older with osteoarthritis of the knee. Participants had significant pain in their knee the month before joining the study, but had never experienced acupuncture, had not had knee surgery in the previous 6 months, and had not used steroid or similar injections. Participants were randomly assigned to receive one of three treatments: acupuncture, sham acupuncture, or participation in a control group that followed the Arthritis Foundation's self-help course for managing their condition. Patients continued to receive standard medical care from their primary physicians, including anti-inflammatory medications, such as COX-2 selective inhibitors, non-steroidal anti-inflammatory drugs, and opioid pain relievers. "For the first time, a clinical trial with sufficient rigor, size, and duration has shown that acupuncture reduces the pain and functional impairment of osteoarthritis of the knee," said Stephen E. Straus, M.D., NCCAM Director. "These results also indicate that acupuncture can serve as an effective addition to a standard regimen of care and improve quality of life for knee osteoarthritis sufferers. NCCAM has been building a portfolio of basic and clinical research that is now revealing the power and promise of applying stringent research methods to ancient practices like acupuncture."

Keyword: Pain & Touch
Link ID: 6614 - Posted: 06.24.2010

The National Institutes of Health (NIH) announced today that research investigators suspended, until further notice, the use of two drugs, naproxen (220 mg twice a day) and celecoxib (200 mg twice a day), in a large, three-arm, national Alzheimer’s disease prevention trial sponsored by the National Institute on Aging (NIA), a part of the NIH. The trial, called the Alzheimer’s Disease Anti-Inflammatory Prevention Trial (or ADAPT) was designed to assess the potential benefit of long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) — naproxen (Aleve™) and the COX-2 inhibitor celecoxib (Celebrex™ ) in decreasing the risk of developing Alzheimer’s Disease in people 70 years of age or older who were considered to be at increased risk because of family history, but did not have symptoms of the disease. Approximately 2400 volunteer participants were randomly assigned to receive naproxen, celecoxib, or placebo for periods of time up to three years. Although no significant increase in risk for celecoxib was found in this trial, the use of these drugs in the study was suspended in part because of findings reported last week from a National Cancer Institute (NCI) trial to test the effectiveness of celecoxib in preventing colon cancer. In addition, however, data from the ADAPT trial indicated an apparent increase in cardiovascular and cerebrovascular events among the participants taking naproxen when compared with those on placebo. “This step is being taken as a precautionary measure to ensure the safety of the study’s participants,” said NIH Director, Elias A. Zerhouni, M.D. “The investigators made their decision based on the risk/benefit analysis specific to this trial,” added Dr. Zerhouni.

Keyword: Alzheimers
Link ID: 6613 - Posted: 06.24.2010

By ELIZABETH WOLFE WASHINGTON - Nearly three-fourths of older Americans support legalizing marijuana for medical use, according to a poll done for the nation's largest advocacy group for seniors. More than half of those questioned said they believe marijuana has medical benefits, while a larger majority agreed the drug is addictive. AARP, with 35 million members, says it has no political position on medical marijuana and that its local branches have not chosen sides in the scores of state ballot initiatives on the issue in recent elections. But with medical marijuana at the center of a Supreme Court case to be decided next year, and nearly a dozen states with medical marijuana laws on their books, AARP decided to study the issue. "The use of medical marijuana applies to many older Americans who may benefit from cannabis," said Ed Dwyer, an editor at AARP The Magazine, which will discuss medical marijuana in its March/April issue appearing in late January. © 2004 The Associated Press

Keyword: Drug Abuse
Link ID: 6612 - Posted: 06.24.2010

By PAUL ELIAS, AP Biotechnology Writer IRVINE, Calif. - So far, not a single person has been helped by human embryonic stem cells. But in cramped university labs, a young neurobiologist with movie star good looks, a Carl Sagan-like fondness for the popular media and an entrepeneur's nose for profits is getting tantalizingly close. Hans Keirstead is making paralyzed rats walk again by injecting them with healthy brain cells sussed from a reddish soup of human embryonic stem cells he and his colleagues have created. Keirstead hopes to apply his therapy to humans by 2006. If his ambitious timetable keeps to schedule, Keirstead's work will be the first human embryonic stem cell treatment given to humans. "I have been shocked, thrilled and humbled at the progress that I have made," Keirstead, 37, said in an interview in his University of California-Irvine office, which is dominated by a 4- by 8-foot collage of famous rock stars created by his artist brother. "I just want to see one person who is bettered by something that I created." Keirstead has been turning stem cells into specialized cells that help the brain's signals traverse the spinal cord. Those new cells have repaired damaged rat spines several weeks after they were injured. For the last two years, he has shown dramatic video footage of walking healed rats to scientific gatherings and during campaign events to promote California's $3 billion bond measure to fund stem cell work, which passed in November. Copyright © 2004 The Associated Press. Copyright © 2004 Yahoo! Inc.

Keyword: Regeneration; Stem Cells
Link ID: 6611 - Posted: 06.24.2010

St. Paul, Minn. – Anger and other negative emotions may be triggers for ischemic stroke, according to a study published in the December 14 issue of Neurology, the scientific journal of the American Academy of Neurology. The study found that people who had strokes were more likely to have experienced anger or negative emotions in the two hours prior to the stroke than at the same time the day before the stroke. They were also more likely to have reacted quickly to a startling event, such as getting out of bed suddenly after hearing a grandchild fall down and cry or standing up from a chair quickly after hearing an unexpected loud noise. The people were also more likely to have experienced anger, negative emotions, or sudden changes in body position in the two hours before the stroke than they were, on average, in the year before the stroke. “We know a lot about risk factors that make people more likely to have a stroke in their lifetime, such as smoking and high blood pressure, but until now we haven’t had any information on what causes a stroke to occur at a particular time,” said study author Silvia Koton, PhD, MOccH, RN, of Tel Aviv University and the Israel Center for Disease Control. “These findings may help us understand how these triggers result in stroke. We can also investigate whether people at a high risk of stroke can make behavior changes. The possibility of preventive medications to lessen the risk of stroke among specific high-risk groups might also be studied.”

Keyword: Stroke; Emotions
Link ID: 6610 - Posted: 06.24.2010

Scientists have devised a way of checking brain fluid levels which they say should eventually reduce the need for painful lumbar punctures. The Southampton University team say the technique, which uses headphones linked to a computer, could be particularly useful in treating children. Existing methods for measuring pressure in the brain can be painful, hazardous and distressing, they say. Details of the research were presented to a Physiological Society conference. Doctors who need to measure fluid pressure currently only have the choice of carrying out a lumbar puncture - where a sample of cerebrospinal fluid that surrounds the spinal cord is removed using a needle - or surgically implanting a pressure sensor in the head. The scientists say their research, which also involved experts in London, could offer a non-invasive aid to the diagnosis and treatment of conditions such as meningitis, head injury and sleeping disorders. They say the technology could also help monitor raised pressure in the brain and its potentially damaging effects in patients with conditions such as high blood pressure, people undergoing coronary bypass heart surgery, or patients who are in comas. They say it could even be used by astronauts in space. They experience changes to the fluid pressure to redistribute itself, causing space sickness and changes to understanding. The researchers have developed a device called a cerebral and cochlear fluid pressure (CCFP) analyser. The patient wears headphones with an earplug that is linked to a computer and monitors the fluid pressure in the brain. The CCFP analyser monitors brain pressure activity in the cochlear aqueduct, a small channel that connects the inner ear with the brain. Pressure waves from the brain are transferred through the minute structures within the ear and can be measured at the ear drum. (C)BBC

Keyword: Miscellaneous
Link ID: 6609 - Posted: 12.18.2004

PHILADELPHIA -- Are we ready for a future where brain scans invade our private thoughts? Will we have to alter our brains chemically to keep competitive at our jobs? Could science determine that "souls" do not exist, and, if so, what does that mean for how we think of ourselves as human beings? The cover story in this month edition of the journal Trends in Cognitive Sciences, released today, tackles these questions about the growing influence of neuroscience on 21st-century life. University of Pennsylvania researcher Martha Farah outlines advances in knowledge about the brain and how new technology enables us to monitor and manipulate it. "What the late 20th century was for molecular genetics a time of great scientific breakthroughs and unprecedented ethical challenges the early 21st century is proving to be for neuroscience," said Farah, a professor in Penn Department of Psychology and director of Penn Center for Cognitive Neuroscience. "There is so much activity in this area now, it has gotten its own name, separate from bioethics more generally. It called 'neuroethics.'" Copyright © 2004, University of Pennsylvania

Keyword: Emotions
Link ID: 6608 - Posted: 06.24.2010

Is the pain relief that magnetic bracelets appear to provide to people with conditions like osteoarthritis just one more example of the placebo effect? Probably, suggests the latest study. Attracted by the promise of cheap, safe pain relief, people around the world spent an estimated $5 billion on magnetic bracelets in 1999. "The public wants medication with no side effects," says Mark Caselli of the New York College of Podiatric Medicine in the US, who has carried out work on the possible use of magnets to treat heel pain. Even if they do work, many questions remain unanswered, including what strength magnet is best, which conditions can be treated and how regularly the bracelet should be worn. But studies to answer these questions are hampered because people can easily determine whether they been given have a real magnetic bracelet or non-magnetic placebo - either their bracelet sticks to their keys, or it does not. To try to tackle this problem, a study led by Tim Harlow of the College Surgery in Cullompton, Devon, UK, used a second type of control bracelet. © Copyright Reed Business Information Ltd

Keyword: Pain & Touch
Link ID: 6607 - Posted: 06.24.2010

Devices to monitor and correct abnormal heart beats could prevent unexpected epilepsy deaths, researchers suggest. As many as 1,000 cases of Sudden Unexpected Death in Epilepsy (SUDEP) occur each year in the UK. Some are thought to be due to spells of irregular heart rate during seizures, which can be missed by routine checks. An implant can continuously monitor the heart and show which patients need a pacemaker, the University College London team told the Lancet. Professor John Duncan's team at the Institute of Neurology fitted 20 epilepsy patients with the loop recording device, which monitored heart rhythms for up to 22 months. Heart rhythms were recorded during 377 of a total of 3,377 seizures reported by the patients. The implants, inserted just above the heart, picked up eight episodes of serious drops in heart rate during the seizures. Four patients, who were subsequently given pacemakers, all experienced periods in which the heartbeat ceased temporarily or went very slowly. In three of these instances the heart irregularity would have been fatal had they not been fitted with the pacemaker, the researchers believe. Professor Duncan said: "Most of the cardiac events detected by the device would not have been picked up during routine ECG monitoring, meaning these loop recorders offer a substantial improvement in spotting potentially fatal heart arrhythmias in these patients. (C)BBC

Keyword: Epilepsy
Link ID: 6606 - Posted: 12.17.2004