By Christof Koch Each new generation of astronomers discovers that the universe is much bigger than their predecessors imagined. The same is also true of brain complexity. Every era’s most advanced technologies, when applied to the study of the brain, keep uncovering more layers of nested complexity, like a set of never ending Russian dolls. We now know that there are up to 1,000 different subtypes of nerve cells and supporting actors—the glia and astrocytes—within the nervous system. Each cell type is defined by its chemical constituents, neuronal morphology, synaptic architecture and input-output processing. Different cell types are wired up in specific ways. For example, a deep layer 5 pyramidal neuron might snake its gossamer-thin output wire, the axon, to a subcortical target area while also extending a connection to an inhibitory local neuron. Understanding how the brain’s corticothalamic complex creates any one conscious sensation necessitates delineating these underlying circuits for the 100 billion cells in the brain. Bulk tissue technologies such as functional brain imaging or electroencephalography identify specific brain regions related to vision, pain or memory. Yet they are unable to resolve details at the all-important circuit level. Brain imaging tracks the power consumption of a million neurons, irrespective of whether they are excitatory or inhibitory, project locally or globally, and so on. For progress on consciousness, something drastically more refined is needed. © 2010 Scientific American,

Keyword: Brain imaging
Link ID: 13841 - Posted: 06.24.2010

by Ewen Callaway If you want to live to a grand old age, then smile – and make sure you mean it. Pro baseball players in the 1950s who genuinely beamed in their official photographs tended to outlive more sullen-looking sportsmen and those who put on fake smiles. Players from the US major league with honest grins lived an average of seven years longer than players who didn't smile for the camera and five years longer than players who smiled unconvincingly, conclude Ernest Abel and Michael Kruger at Wayne State University in Detroit, Michigan. It's known that happy people tend to be healthy too. Kruger and Abel wondered whether this relationship would be reflected in the smiles and longevity of baseball players. Genuine smiles are known as Duchenne smiles after the 19th-century neurologist who defined them in detail. They engage muscles both near the corners of the mouth and around the eyes – the zygomatic major and the orbicularis oculi respectively. Fake, "non-Duchenne" smiles exercise only mouth muscles. Smile survival With training, these muscles are easy to recognise in photographs. So Abel and four colleagues who were not aware of what the study was investigating, but were trained to analyse smiles, looked at vintage photographs of 230 major leaguers who played in the 1952 season. The researchers classified them as non-smilers, Duchenne smilers or non-Duchenne smilers. Then they looked up the lifespans of the 184 players who had already died. © Copyright Reed Business Information Ltd

Keyword: Emotions
Link ID: 13840 - Posted: 06.24.2010

Greg Miller Diagnoses of mental disorders in children and adolescents rose dramatically during the past 2 decades. Juvenile cases of bipolar disorder, once thought to strike only in adulthood, jumped 40-fold between 1993 and 2004 in the United States, according to one widely cited study. Autism estimates leapt from 1 in 1500 to as high as 1 in 90 over a similar time period. Such figures have fueled an intense debate about whether the surge is real or reflects a trend toward overzealous diagnoses and a tendency to pathologize normal youthful behavior. Against this backdrop, the clinicians and researchers working on revisions to the psychiatrists' bible, the Diagnostic and Statistical Manual of Mental Disorders (DSM), have been wrestling with how to improve the diagnosis of mental disorders in these age groups. It's not clear how their suggestions, released last month (Science, 12 February, p. 770), would affect the prevalence of mental disorders if adopted, but they are already altering the discussion. The most substantial proposals include a reclassification of autism spectrum disorders, a new diagnosis of post-traumatic stress disorder (PTSD) tailored to preschool children, and a brand-new diagnosis called temper dys-regulation disorder with dysphoria (TDD) that members of the DSM work group hope will stem what they see as a false epidemic of juvenile bipolar disorder. © 2010 American Association for the Advancement of Science

Keyword: Autism; Schizophrenia
Link ID: 13839 - Posted: 06.24.2010

National Institutes of Health (NIH) scientists investigating how prion diseases destroy the brain have observed a new form of the disease in mice that does not cause the sponge-like brain deterioration typically seen in prion diseases. Instead, it resembles a form of human Alzheimer's disease, cerebral amyloid angiopathy, that damages brain arteries. The study results, reported by NIH scientists at the National Institute of Allergy and Infectious Diseases (NIAID), are similar to findings from two newly reported human cases of the prion disease Gerstmann-Straussler-Scheinker syndrome (GSS). This finding represents a new mechanism of prion disease brain damage, according to study author Bruce Chesebro, M.D., chief of the Laboratory of Persistent Viral Diseases at NIAID’s Rocky Mountain Laboratories. Prion diseases, also known as transmissible spongiform encephalopathies, primarily damage the brain. Prion diseases include mad cow disease or bovine spongiform encephalopathy in cattle; scrapie in sheep; sporadic Creutzfeldt-Jakob disease (CJD), variant CJD and GSS in humans; and chronic wasting disease in deer, elk and moose. The role of a specific cell anchor for prion protein is at the crux of the NIAID study. Normal prion protein uses a specific molecule, glycophosphoinositol (GPI), to fasten to host cells in the brain and other organs. In their study, the NIAID scientists genetically removed the GPI anchor from study mice, preventing the prion protein from fastening to cells and thereby enabling it to diffuse freely in the fluid outside the cells.

Keyword: Prions
Link ID: 13838 - Posted: 06.24.2010

By Jennifer Viegas Male mice drive females wild with ultrasonic love songs, suggests a new study. Since song quality varies, the mice world has its Justin Timberlake-like stars that impress females with their talents more than other willing, but not so able, males do. While no one is yet certain what makes a "hit love song" in the mice world, lead author Kerstin Musolf told Discovery News that "it could be a question of different syllable types or endurance in singing or a combination of both -- all together it could help the female to choose the best mate." Musolf is a researcher in the Konrad Lorenz Institute for Ethology at the Austrian Academy of Sciences. She and her team believe their study, which has been accepted for publication in the journal Animal Behavior, is the first to examine the ultrasonic vocalizations of wild-derived house mice. These calls have frequencies above those of sounds audible to humans and many other animals. Using special equipment, the researchers recorded and observed offspring of house mice caught at three locations in Ganserndorf, Austria. When males got a whiff of scent from available, non-related, adult females, they sang their hearts out at varying degrees. Females were more attracted to songs crooned by unfamiliar males that weren't related to them. Women sometimes flirt by pushing back their hair. Female mice do something similar by cleaning themselves vigorously all over. © 2010 Discovery Communications, LLC.

Keyword: Sexual Behavior; Hearing
Link ID: 13837 - Posted: 06.24.2010

A new hand-held device that delivers a magnetic pulse to the back of the head could become an alternative to drug treatment for people with migraines. A trial found that 40% of patients were pain free two hours after using the device. Research showed there were no serious side-effects and patients found the device easy to use at home. However, doctors say more research is needed to work out the timing of the doses. Experts from the Albert Einstein College of Medicine in New York carried out the trial to assess the safety and effectiveness of the device. Previous trials have only involved large, expensive devices which have to be used in a clinic. The hand-held device emits a single-pulse transcranial magnetic stimulation (sTMS), thought to disrupt the electrical events in the brain which cause the preliminary symptoms of migraines with aura. Auras are sensory or visual disturbances that occur before a migraine headache sets in. These include visual symptoms such as spots of light and zigzag lines. Other symptoms include tingling, numbness and difficulties with speaking. Two hundred patients were asked to use the device to treat migraines with aura over three months. Half of those patients were given placebo treatment. The findings, to be published in The Lancet Neurology, showed that the real magnetic pulse from the device was significantly more effective than placebo treatment. More patients were pain free two, 24 and 48 hours afterwards. (C)BBC

Keyword: Pain & Touch
Link ID: 13836 - Posted: 03.04.2010

Women need to be treated for stroke as soon as possible.Women need to be treated for stroke as soon as possible. (CBC) Women who don't get a clot-busting drug after a stroke might fare worse than men who don't receive the drug, a University of Calgary study suggests. Both sexes fared equally well when given the drug known as tissue plasminogen activator, or tPA, which breaks up the blood clots that cause a stroke. "It's exactly analogous to you [having] a blocked kitchen sink," study author Dr. Michael Hill said in an interview. "You put some Drano in there, it churns up the clot and your sink works again." The researchers' findings were reported in this week's issue of the journal Neurology. The study looked at data on 2,113 stroke sufferers collected by the Canadian Stroke Network. Of these, 232 were treated with tPA within three hours of their stroke and 44 per cent of them were women. The three hours is the maximum window recommended under the guidelines for administering tPA. "Women need to be treated for stroke as soon as possible," Hill said in news release. "We found that women who weren't treated had a worse quality of life after stroke than men. However, the good news is that women who were treated responded just as well as men to the treatment." © CBC 2010

Keyword: Stroke; Sexual Behavior
Link ID: 13835 - Posted: 06.24.2010

by Jessica Hamzelou PAIN intensity, the most personal of experiences, can now be measured from the outside, say researchers who scanned the brains of young men who were fresh out of the operating theatre. Their claim reopens the debate over whether pain can be measured objectively. It might even be possible to gauge the pain felt by newborn babies, fetuses, "locked-in" patients, who can't communicate with the outside world, and animals. "The definition of pain is that it is subjective, and until now an objective measurement has remained elusive," says Morten Kringelbach of the University of Oxford, who has previously worked on a method of objective pain measurement and was not involved in the most recent work. Functional MRI scans have been used before to identify brain areas that "light up" when someone is in pain. Because oxygenated and deoxygenated blood have different levels of magnetisation they look different under MRI. A technique for analysing fMRI scans called BOLD, for blood-oxygen-level dependent, exploits this difference to determine which areas are most active: high oxygen is a sign that a brain region is particularly active. While BOLD can reveal if the amount of oxygen flowing to a particular region has increased or decreased, it doesn't measure by how much. © Copyright Reed Business Information Ltd.

Keyword: Pain & Touch; Brain imaging
Link ID: 13834 - Posted: 06.24.2010

By Susan Milius In females of the beetle Onthophagus sagittarius, competition for dung to wrap eggs and feed young favors the evolution of exaggerated horns. Sean Stankowski So many moms, so little fresh excrement. Though male animals are usually the ones to sport horns and other weapons, in one species of beetle battle armor comes in handy for the ladies, who use their oversized horns in fights over dung. Females of the species Onthophagus sagittarius who had heftier horns won control of more available dung and thus laid more eggs, evolutionary biologists Nicola Watson and Leigh Simmons of the University of Western Australia in Crawley found in lab tests. Competition for quality dung is the evolutionary force selecting for feminine weaponry in this species, the researchers conclude in a paper to be published online the week of March 2 in Proceedings of the Royal Society B. “It’s a rare example of this type of evolutionary event for sure,” says biologist Ted Stankowich of the University of Massachusetts, Amherst. Horns on bulls, antlers on stags and other guy weapons have preoccupied scientists who study evolution, Stankowich says. Darwin proposed that male weaponry arose from the struggle between rivals for access to females, and later work has found plenty of examples that fit that scenario. © Society for Science & the Public 2000 - 2010

Keyword: Aggression; Evolution
Link ID: 13833 - Posted: 06.24.2010

by Greg Miller Alzheimer's researchers have faced a series of frustrations in recent years as one promising compound after another has flopped in late-stage clinical trials. Unfortunately, the string continues with the announcement today that another closely watched trial—for a drug called dimebon—has failed. Dimebon was something of a dark horse. An antihistamine introduced in Russia in 1983, it turned up in a screen for potential Alzheimer's drugs and led to a clinical trial that yielded remarkably encouraging results: In 2008, researchers reported in The Lancet that 78 people with mild to moderate Alzheimer's disease who took dimebon showed significant improvements in memory and cognition, as well as the ability to carry out the activities of daily life. The new study was led by Medivation, a San Francisco, Californai-based biopharmaceutical company, and Pfizer (which reportedly paid $225 million to license the drug). It enrolled 598 patients with mild to moderate Alzheimer's. This time, there were no significant differences between the dimebon and placebo groups. "The results ... are unexpected, and we are disappointed for the Alzheimer's community," Medivation's president and CEO, David Hung, said in a statement. Some researchers who study the mechanisms of Alzheimer's aren't surprised, however. "I think a lot of us have been saying the same thing ... that it looks too good to be true, but let's hope not for the sake of patients," says Harvard University's Rudolph Tanzi. © 2010 American Association for the Advancement of Science.

Keyword: Alzheimers
Link ID: 13832 - Posted: 06.24.2010

By Katie Moisse Our bodies are wired to move, and damaged wiring is often impossible to repair. Strokes and spinal cord injuries can quickly disconnect parts of the brain that initiate movement with the nerves and muscles that execute it, and neurodegenerative disorders such as Parkinson's disease and amyotrophic lateral sclerosis (ALS) draw the process out to the same effect. Scientists have been looking for a way to bypass damaged nerves by directly connecting the brain to an assistive device—like a robotic limb—through brain-computer interface (BCI) technology. Now, researchers have demonstrated the ability to nonintrusively record neural signals outside the skull and decode them into information that could be used to move a prosthetic. Past efforts at a BCI to animate an artificial limb involved electrodes inserted directly into the brain. The surgery required to implant the probes and the possibility that implants might not stay in place made this approach risky. The alternative—recording neural signals from outside the brain—has its own set of challenges. "It has been thought for quite some time that it wasn't possible to extract information about human movement using electroencephalography," or EEG, says neuroscientist and electrical engineer Jose Contreras-Vidal. In trying to record the brain's electrical activity off the scalp, he adds, "people assumed that the signal-to-noise ratio and the information content of these signals were limited." Evidently, that is not the case. In the March issue of The Journal of Neuroscience, Contreras-Vidal and his team from the bioengineering and kinesiology departments at the University of Maryland, College Park, show that the noisy brain waves recorded using noninvasive EEG can be mathematically decoded into meaningful information about complex human movements. © 2010 Scientific American

Keyword: Robotics; ALS-Lou Gehrig's Disease
Link ID: 13831 - Posted: 06.24.2010

With its generalized symptoms of pain, fatigue and digestive issues, fibromyalgia can often hide as something else for many years. Worse, some professionals doubt the existence of this condition, which can also cause chest pains, brain fog and depression. Here, six men and women speak about living with fibromyalgia. What is it like to live with a chronic disease, mental illness or confusing condition? In Patient Voices, we feature first person accounts of the challenges patients face as they cope with various health issues. Copyright 2010 The New York Times Company

Keyword: Pain & Touch; Emotions
Link ID: 13830 - Posted: 03.04.2010

by Ewen Callaway A chemical produced during sex and linked to addiction has been visualised in a scanner as it washes across rats' brains. The feat means that functional magnetic resonance imaging (fMRI), a workhorse of neuroscience, can now be used to observe the flow of brain chemicals, not just oxygen-rich blood. By pinpointing increases in blood oxygenation in the brain in response to different events – a sign that specific groups of neurons are active – fMRI is responsible for some of the hottest findings about the brain. Now Alan Jasanoff at the Massachusetts Institute of Technology and colleagues have extended its power. His team repeatedly mutated a magnetic, iron-containing enzyme that "lights up" in fMRI readings. With each mutation, the researchers tested its tendency to bind to dopamine, a learning and reward chemical in the brain involved in sex and addictive behaviours. Mutations that increased this tendency were combined, resulting in a molecule that was both magnetic and strongly attracted to dopamine. The team injected the molecule into the brains of rats, in a region laden with dopamine-producing cells. When given a chemical that triggers dopamine release, that area "lit up" under fMRI. Because the molecule must be injected into the brain, this kind of chemical-based fMRI won't be applied to humans anytime soon, says Jasanoff, but it could be used to probe addiction and disease using animals. © Copyright Reed Business Information Ltd

Keyword: Brain imaging
Link ID: 13829 - Posted: 06.24.2010

By Azadeh Ansari, CNN (CNN) -- Atrazine, a weed killer widely used in the Midwestern United States and other agricultural areas of the world, can chemically "castrate" male frogs and turn some into females, according to a new study. New research suggests the herbicide may be a cause of amphibian declines around the globe, said biologists at the University of California-Berkeley, who conducted the study. The findings are being published this week in the journal Proceedings of the National Academy of Sciences. Researchers found that long-term exposure to low levels of atrazine -- 2.5 parts per billion of water -- emasculated three-quarters of laboratory frogs and turned one in 10 into females. Scientists believe the pesticide interferes with endocrine hormones, such as estrogen and testosterone. "The effects of atrazine in the long term have been shown to demasculinize or chemically castrate [frogs], combined with complete feminization of some animals," said lead researcher Tyrone B. Hayes, a biologist and herpetologist at the University of Berkeley. "We need to reconfigure how we evaluate chemicals in the environment and the impact on environmental health and public health," he said. Hayes found that 10 percent of the exposed genetic male frogs developed into functional females who copulated with unexposed males and produced viable eggs. The other 90 percent of the exposed male frogs expressed decreased libido, reduced sperm count and decreased fertility, among other findings. © 2010 Cable News Network.

Keyword: Sexual Behavior; Neurotoxins
Link ID: 13828 - Posted: 06.24.2010

By LISA SANDERS, M.D. The middle-aged woman perched on the edge of a plastic chair as the doctor explained his thoughts on why her son was having persistent headaches. Suddenly, she toppled forward, collapsing onto the linoleum floor. Dr. Philip Ledereich hurried over to the woman. “Call 911,” he shouted to his nurse. “The patient’s mother has fainted.” Was the fainting brought on simply by stress? Or could there be an underlying neurological problem? Ledereich, an ear, nose and throat specialist in Clifton, N.J., first met the mother a couple of weeks before, when she herself came in as a patient. She was fainting several times a day, and no one knew why. Ledereich hadn’t been able to figure it out, either. Despite that, she took her son to see him for the treatment of a chronic sinus infection. Ledereich was describing various treatment alternatives when the woman pitched to the floor. She had been having these spells almost daily for the past several months, she told him at their first appointment. She was 49, a nurse, and she considered herself pretty healthy until one Saturday nearly three months earlier. That day she had just put on her shoes to go to a bar mitzvah, and as she straightened up she felt a fluttering sensation in her stomach. The next minute she was on the floor. Her husband rushed to her side. She could hear him calling her name, but she couldn’t answer him; she couldn’t even open her eyes. Copyright 2010 The New York Times Company

Keyword: Narcolepsy; Sleep
Link ID: 13827 - Posted: 06.24.2010

LONDON - Young people who smoke cannabis or marijuana for six years or more are twice as likely to have psychotic episodes, hallucinations or delusions than people who have never used the drug, scientists said on Monday. The findings adds weight to previous research which linked psychosis with the drug — particularly in its most potent form as "skunk" — and will feed the debate about the level of controls over its use. Despite laws against it, up to 190 million people around the world use cannabis, according to United Nations estimates, equating to about 4 percent of the adult population. John McGrath of the Queensland Brain Institute in Australia studied more than 3,801 men and women born between 1981 and 1984 and followed them up after 21 years to ask about their cannabis use and assessed them for psychotic episodes. Around 18 percent reported using cannabis for three or fewer years, 16 percent for four to five years and 14 percent for six or more years. For most of the study, researchers didn't measure the frequency of cannabis use among subjects, but rather whether they used at all. "Compared with those who had never used cannabis, young adults who had six or more years since first use of cannabis were twice as likely to develop a non-affective psychosis (such as schizophrenia)," McGrath wrote in a study published in the Archives of General Psychiatry journal. Copyright 2010 Reuters.

Keyword: Drug Abuse; Schizophrenia
Link ID: 13826 - Posted: 06.24.2010

By JOYCE COHEN For football fans, the indelible image of last month’s Super Bowl might have been quarterback Drew Brees’s fourth-quarter touchdown pass that put the New Orleans Saints ahead for good. But for audiologists around the nation, the highlight came after the game — when Mr. Brees, in a shower of confetti, held aloft his 1-year-old son, Baylen. The boy was wearing what looked like the headphones worn by his father’s coaches on the sideline, but they were actually low-cost, low-tech earmuffs meant to protect his hearing from the stadium’s roar. Specialists say such safeguards are critical for young ears in a deafening world. Hearing loss from exposure to loud noises is cumulative and irreversible; if such exposure starts in infancy, children can live “half their lives with hearing loss,” said Brian Fligor, director of diagnostic audiology at Children’s Hospital Boston. “This message needs to be conveyed to parents over and over again,” Dr. Fligor said. “If a child attends only one loud sporting event, it isn’t a big deal. But for those kids who will be going to football games throughout their lives, as Drew Brees’s kids will, it’s a very big deal. A young, tender ear may not be able to withstand damage.” According to the National Institute for Occupational Safety and Health, more than 15 minutes of exposure to 100 decibels is unsafe. The noise in a football stadium can reach 100 to 130 decibels. Copyright 2010 The New York Times Company

Keyword: Hearing
Link ID: 13825 - Posted: 06.24.2010

By TARA PARKER-POPE The basic formula for gaining and losing weight is well known: a pound of fat equals 3,500 calories. That simple equation has fueled the widely accepted notion that weight loss does not require daunting lifestyle changes but “small changes that add up,” as the first lady, Michelle Obama, put it last month in announcing a national plan to counter childhood obesity. In this view, cutting out or burning just 100 extra calories a day — by replacing soda with water, say, or walking to school — can lead to significant weight loss over time: a pound every 35 days, or more than 10 pounds a year. While it’s certainly a hopeful message, it’s also misleading. Numerous scientific studies show that small caloric changes have almost no long-term effect on weight. When we skip a cookie or exercise a little more, the body’s biological and behavioral adaptations kick in, significantly reducing the caloric benefits of our effort. But can small changes in diet and exercise at least keep children from gaining weight? While some obesity experts think so, mathematical models suggest otherwise. The first lady, Michelle Obama, spoke last month at the White House about her “Let’s Move” initiative, which aims to change the way children eat and play. Copyright 2010 The New York Times Company

Keyword: Obesity
Link ID: 13824 - Posted: 06.24.2010

By Tina Hesman Saey In the heavyweight division, immune cells embedded in fat pack some extra disease-causing punches, a new study shows. Those punches involve potentially dangerous proteins linked to inflammation, heart disease and diabetes. Something in the adipose tissue, or fat, of overweight people primes immune cells called macrophages nestled within the tissue to release the proteins when the cells sense high levels of fat in the bloodstream, researchers report in the Feb. 24 Science Translational Medicine. The discovery may lead to treatments that could block disease formation in overweight or obese people. Blood levels of free fatty acids, such as triglycerides, rise after a high-fat meal and, in obese people, are often constantly elevated to levels two to three times higher than normal, says Preeti Kishore, an endocrinologist at the Albert Einstein College of Medicine in New York City. In the new study, Kishore and her colleagues show that these types of fat particles prod immune cells called macrophages to make PAI-1, a protein linked to heart disease. The protein, whose full name is plasminogen activator inhibitor-1, keeps blood clots, which can cause strokes or heart attacks, from breaking up. The fatty acids also triggered the release of inflammation-causing proteins called TNF-alpha and IL-6, the researchers found. Inflammation caused by those and other proteins is thought to play a role in type 2 diabetes in obese people. © Society for Science & the Public 2000 - 2010

Keyword: Obesity; Neuroimmunology
Link ID: 13823 - Posted: 06.24.2010

by Richard L. Doty FOR more than 50 years, researchers - many of them prominent scientists - have assumed that single or small sets of innate biochemicals trigger behavioural and endocrine responses in mammals of the same species. These agents, never chemically identified, were labelled "pheromones". The term was borrowed from insect studies of the early 1930s, where it replaced "ectohormone" (external hormone) to describe the single biochemicals which trigger predictable responses in relatively simple organisms. It was not until the 1960s that the quest to find pheromones in mammals became a really big deal. In Science in 1962, endocrinologists Alan Parkes and Hilda Bruce wrote that "endocrinology has flowered magnificently in the last 40 years; exocrinology is now about to blossom". The father of sociobiology, E. O. Wilson, suggested the possibility that "pheromones are in a special sense the lineal ancestors of hormones" in a 1972 Scientific American article. Even Alex Comfort, author of the 1970s best-seller The Joy of Sex, argued in a Nature paper that pheromones were likely to exist in humans. Since then, a plethora of studies has implicated pheromones in many mammalian activities, including sex, maternal behaviour, fighting, nesting, and the recognition of members of one's own species. Pheromones have been said to accelerate the onset of puberty, block pregnancies and influence oestrous cycles and hormonal surges in a range of mammals, although no one has ever identified the agents involved. © Copyright Reed Business Information Ltd

Keyword: Chemical Senses (Smell & Taste)
Link ID: 13822 - Posted: 06.24.2010