Researchers believe they have identified why a mutation in a particular gene can lead to obesity. Mouse experiments suggested the body's message to "stop eating" was blocked if the animals had the mutation. The study, published in Nature Medicine, said the brain's response to appetite hormones was being disrupted. The Georgetown University Medical Center researchers hope their findings could lead to new ways to control weight. Many genes have been linked to obesity, one of them - brain-derived neurotrophic factor gene - has been shown to play a role in putting on weight in animal and some human studies. However, scientists at the Georgetown University Medical Center said the explanation for this link was unknown. In studies on mice which had been genetically modified to have the mutation, the mice consumed up to 80% more food than normal. After a meal, hormones such as insulin and leptin should tell the brain that the body is full and should stop eating. The researchers showed that in the mutated mice the message was not being passed on from the hormones in the blood to the correct part of the brain. BBC © 2012

Keyword: Obesity; Genes & Behavior
Link ID: 16537 - Posted: 03.19.2012

By ANNIE MURPHY PAUL Brain scans are revealing what happens in our heads when we read a detailed description, an evocative metaphor or an emotional exchange between characters. Stories, this research is showing, stimulate the brain and even change how we act in life. Researchers have long known that the “classical” language regions, like Broca’s area and Wernicke’s area, are involved in how the brain interprets written words. What scientists have come to realize in the last few years is that narratives activate many other parts of our brains as well, suggesting why the experience of reading can feel so alive. Words like “lavender,” “cinnamon” and “soap,” for example, elicit a response not only from the language-processing areas of our brains, but also those devoted to dealing with smells. In a 2006 study published in the journal NeuroImage, researchers in Spain asked participants to read words with strong odor associations, along with neutral words, while their brains were being scanned by a functional magnetic resonance imaging (fMRI) machine. When subjects looked at the Spanish words for “perfume” and “coffee,” their primary olfactory cortex lit up; when they saw the words that mean “chair” and “key,” this region remained dark. The way the brain handles metaphors has also received extensive study; some scientists have contended that figures of speech like “a rough day” are so familiar that they are treated simply as words and no more. Last month, however, a team of researchers from Emory University reported in Brain & Language that when subjects in their laboratory read a metaphor involving texture, the sensory cortex, responsible for perceiving texture through touch, became active. Metaphors like “The singer had a velvet voice” and “He had leathery hands” roused the sensory cortex, while phrases matched for meaning, like “The singer had a pleasing voice” and “He had strong hands,” did not. © 2012 The New York Times Company

Keyword: Language; Brain imaging
Link ID: 16536 - Posted: 03.19.2012

By Kathleen McAuliffe No one would accuse Jaroslav Flegr of being a conformist. A self-described “sloppy dresser,” the 53-year-old Czech scientist has the contemplative air of someone habitually lost in thought, and his still-youthful, square-jawed face is framed by frizzy red hair that encircles his head like a ring of fire. Certainly Flegr’s thinking is jarringly unconventional. Starting in the early 1990s, he began to suspect that a single-celled parasite in the protozoan family was subtly manipulating his personality, causing him to behave in strange, often self-destructive ways. And if it was messing with his mind, he reasoned, it was probably doing the same to others. The parasite, which is excreted by cats in their feces, is called Toxoplasma gondii (T. gondii or Toxo for short) and is the microbe that causes toxoplasmosis—the reason pregnant women are told to avoid cats’ litter boxes. Since the 1920s, doctors have recognized that a woman who becomes infected during pregnancy can transmit the disease to the fetus, in some cases resulting in severe brain damage or death. T. gondii is also a major threat to people with weakened immunity: in the early days of the AIDS epidemic, before good antiretroviral drugs were developed, it was to blame for the dementia that afflicted many patients at the disease’s end stage. Healthy children and adults, however, usually experience nothing worse than brief flu-like symptoms before quickly fighting off the protozoan, which thereafter lies dormant inside brain cells—or at least that’s the standard medical wisdom. But if Flegr is right, the “latent” parasite may be quietly tweaking the connections between our neurons, changing our response to frightening situations, our trust in others, how outgoing we are, and even our preference for certain scents. And that’s not all. He also believes that the organism contributes to car crashes, suicides, and mental disorders such as schizophrenia. When you add up all the different ways it can harm us, says Flegr, “Toxoplasma might even kill as many people as malaria, or at least a million people a year.” Copyright © 2012 by The Atlantic Monthly Group.

Keyword: Emotions; Aggression
Link ID: 16535 - Posted: 03.19.2012

Distinct patterns of activity — which may indicate a predisposition to care for infants — appear in the brains of adults who view an image of an infant face — even when the child is not theirs, according to a study by researchers at the National Institutes of Health and in Germany, Italy, and Japan. Seeing images of infant faces appeared to activate in the adult's brains circuits that reflect preparation for movement and speech as well as feelings of reward. The findings raise the possibility that studying this activity will yield insights not only into the caregiver response, but also when the response fails, such as in instances of child neglect or abuse. While the researchers recorded participants' brain activity, the participants did not speak or move. Yet their brain activity was typical of patterns preceding such actions as picking up or talking to an infant, the researchers explained. The activity pattern could represent a biological impulse that governs adults' interactions with small children. From their study results, the researchers concluded that this pattern is specific to seeing human infants. The pattern did not appear when the participants looked at photos of adults or of animals — even baby animals. Their findings appear in the journal NeuroImage.

Keyword: Sexual Behavior; Brain imaging
Link ID: 16534 - Posted: 03.17.2012

Martin E. Schwab & Anita D. Buchli Recently, at the annual retreat of the Zurich Neuroscience Center, we ran into a former colleague who had often helped us to prepare for courses we were teaching. But he was not there to teach — he was participating in a demonstration as a patient. A stroke had left him paralysed on one side, wheelchair-bound and unable to speak. He had been looking forward to interacting with the students, but when he could not communicate with them, he broke into tears. After a difficult rehabilitation, he was able to resume some of his work, but he still cannot speak. His arm and leg will probably remain paralysed for the rest of his life. Our colleague was one of the 8.2 million Europeans who experience stroke every year1. The brain is a source of many devastating disorders — such as Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis — and injuries to the spinal cord or brain can lead to lifelong impairments. At present, disabling spinal-cord injuries affect roughly 350,000 people in Europe and 250,000 in the United States. Traumatic brain injuries are about ten times more common. Treatments that could restore lost functions to people with such injuries would radically change their lives and decrease the burden to their families and social environment. The economic interest to drug companies and health insurers seems obvious. Yet drug companies have withdrawn from neuroscience, more so than from any other disease area. Last year, Novartis closed its preclinical neuroscience research facility in Basel, Switzerland. Pfizer, GlaxoSmithKline and AstraZeneca had already made similar moves. Merck and Sanofi are also cutting research on brain diseases. © 2012 Nature Publishing Group

Keyword: Stroke; Schizophrenia
Link ID: 16533 - Posted: 03.17.2012

By HENRY ALFORD COILED viper-like within the word “insomnia” is the terrifying “omnia.” Why does sleeplessness seem all-powerful? Because some nights I can’t get down into the Valley regardless of how many Dolls I lash to my burro. I’m not alone. It’s difficult to go to a Manhattan cocktail party these days and not get roped into a discussion of someone’s insomnia or the relative merits of melatonin and “snore absorption rooms.” If you find yourself buttonholed by a well-heeled but heavy-lidded person, prepare for a slightly defensive diatribe called “Why I Have Recently Purchased a $60,000 Mattress.” Glamorous (and sometimes dubious-sounding) treatments continue to pop up, a fact underlined by last week’s designation by the National Sleep Foundation as sleep awareness week. Europe’s first “nap bar” recently opened in Paris, giving the weary a place to rest on a massage chair or zero-gravity chair. The Grand Resort Bad Ragaz in Switzerland will film your sleeping patterns during the night and then analyze them and suggest cures. At La Mansión del Rio in San Antonio, you’re encouraged to put some of the resort’s “worry dolls” (one doll for each of your worries) under your pillow so that, through Indian magicking, you’ll awake liberated, fresh, burden-free — a person who can crush a plaything solely with the force of his head. In Midtown Manhattan, the Benjamin Hotel employs a sleep concierge, on call to help guests choose from 12 free sleep-friendly pillows, as well as field requests for sleep aids like massages and midnight snacks (e.g., hot chocolate or milk and cookies). © 2012 The New York Times Company

Keyword: Sleep
Link ID: 16532 - Posted: 03.17.2012

Sandrine Ceurstemont, editor, New Scientist TV No, it's not science fiction: a new illusion that looks like a flight through space simultaneously tricks your brain in three different ways. Watch the moving white dots and their shadows as they move forwards and backwards. They should appear to change in contrast, grow and shrink in size and vary in depth, since the distance between the dots and their shadows seems to change. But none of these factors are actually changing: the pairs of dots are only moving to a different position on the screen. Aptly named the Star Trek illusion by researcher Yury Petrov and his team from Northeastern University in Boston, who developed the effect, the trick occurs since our brain perceives the motion as a change in viewing distance. Normally, when you move closer or further away from a scene, colour contrast, depth cues and object size are altered to account for the new viewpoint. So the strong flow in the animation tricks our brain and causes it to infer the new cues it's expecting. In their recent paper, Petrov and his colleague found that our brain first rescales the size of the dots and then adjusts contrast. Although the depth effect was predicted, it was only observed when they produced the new version of the illusion, shown above, containing shadows. The illusion has been submitted to this year's Best Visual Illusion of the Year Contest. © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 16531 - Posted: 03.17.2012

By Katherine Harmon Giant and colossal squid can grow to be some 12 meters long. But that alone doesn’t explain why they have the biggest eyeballs on the planet. At 280 millimeters in diameter, colossal squid eyes are much bigger than those of the swordfish, which at 90 millimeters, measure in as the next biggest peepers. “It doesn’t make sense a giant squid and swordfish are similar in size but the squid’s eyes are proportionally much larger, three times the diameter and 27 times the volume,” Sönke Johnsen, a biologists at Duke University, said in a prepared statement. Why would these cephalopods evolve soccer-ball-size eyes? The better to see you with, of course. Well, not you, exactly—unless you happen to be a hungry sperm whale. Scientists have found that having these extreme eyeballs likely allows these squid to spot whales when they’re still far enough away to escape the huge predators. The findings were described online March 15 in Current Biology. Bigger eyes might seem an obvious solution for acquiring better vision. “For seeing in dim light, a large eye is better than a small eye, simply because it picks up more light,” co-author Dan-Eric Nilsson of Lund University said in a prepared statement. But the low-light, low-contrast world of the pelagic oceans, where these squids and whales live and die, is much murkier than our airy environment here on land. “We have found that for animals living in water, it does not pay to make eyes much bigger than an orange,” Nilsson said. © 2012 Scientific American

Keyword: Vision; Evolution
Link ID: 16530 - Posted: 03.17.2012

By Katherine Harmon Years of surgeries and medications were unable to stop Sultan Kosen’s runaway growth. In 2010 at age 27 and a height of 2.46 meters (eight feet, one inch), he became the world’s tallest living man, according to Guinness World Records. But he wasn’t done growing. Kosen had been diagnosed with a growth disorder at age 10 after doctors in his native Turkey found a tumor on his pituitary gland. The tumor triggered the gland to release too much growth hormone. As a result, he has suffered from both gigantism, a condition in which too much growth hormone is secreted during childhood, and acromegaly, a condition caused by too much growth hormone in adulthood. The tumor was technically benign, but it was lodged near the bottom of his brain, making it difficult to operate on. Thus ensconced, the tumor—along with Kosen’s whole body—continued to grow to dangerous proportions. sultan kosen uva surgery So in May 2010, doctors at the University of Virginia Medical Center put Kosen on new medication to limit growth hormone production. Perhaps more importantly, they were also able to perform gamma-knife radiosurgery on his hard-to-reach tumor. Guided by MRI, the doctors used this super-precise technique, which harnesses high-power gamma rays, to disable the tumor without having to do more dangerous invasive surgery. © 2012 Scientific American

Keyword: Hormones & Behavior
Link ID: 16529 - Posted: 03.17.2012

By Tina Hesman Saey Reading the genetic instruction books of gorillas and chimpanzees has provided more insight into what sets humans apart from their closest primate relatives. The two new studies also provide details about how these primate species may have evolved. Comparing a newly compiled genetic blueprint, or genome, of a western lowland gorilla named Kamilah with the genomes of humans and chimpanzees has revealed that the three species didn’t make a clean break when splitting from a common ancestor millions of years ago. Although humans are more closely related to chimps over about 70 percent of the human genome, about 15 percent of the human genome bears a closer relationship to gorillas. An international group of researchers reports the findings, which come from the first gorilla genome to be deciphered, in the March 8 Nature. A separate study of western chimpanzees, published online March 15 in Science, also has implications for understanding the human-chimp split. The new work shows that humans and chimps have different strategies for shuffling their genetic decks before dealing genes out to their offspring. Neither humans nor chimps shuffle genetic material randomly across the genome. Instead, both species have what are called hot spots, locations in the genetic material where matching sets of chromosomes recombine most often, Gil McVean, a statistical geneticist at the University of Oxford in England and colleagues report. © Society for Science & the Public 2000 - 2012

Keyword: Evolution; Genes & Behavior
Link ID: 16528 - Posted: 03.17.2012

It's not always clever to use brain science as an explanation for the most complex human problems. In the vast literature documenting the possible causes of the financial crises, from tepid governments to loose monetary policy to greedy bankers, there was the more lucid theme of a belief in the infallible nature of modern economic models, those mathematical pieces of wonder that tried to incorporate everything from the weather to political power-plays into the all-encompassing term that is risk. At the heart of this flawed world-view was the idea that economics had become a science much like physics and biochemistry - quantifiable, measurable and able to be modelled. In the wreckage thereafter, the reductionism inherent in such hubris was there for all to see. But the scientism that had inebriated the world of economics is part of a broader trend of viewing our very natures in a stripped back to the biological bones caricature. It is best epitomised by the ubiquity of musings about the brain from those attempting to bolster their authority, which includes everyone from leadership gurus to astrologers. The word is out that human consciousness - from the most elementary tingle of sensation to the most sophisticated sense of self - is identical with neural activity in the human brain and that this extraordinary metaphysical discovery is underpinned by the latest findings in neuroscience. The republic of letters is in thrall to the idea of neuroplasticity, imagining in wonder their brains modifying cells in parallel with their daily meanderings. © 2012 Fairfax Media

Keyword: Brain imaging
Link ID: 16527 - Posted: 03.17.2012

By Victoria Gill Science reporter, BBC Nature Japanese honeybees' response to a hive-invading giant hornet is efficient and dramatic; they form a "bee ball" around it, serving to cook and asphyxiate it. Now, researchers in Japan have measured the brain activity of honeybees when they form this killer ball. One highly active area of the bees' brains, they believe, allows them to generate the constant heat which is deadly for the hornet. The team published their findings in the open-access journal, PLoS One. Prof Takeo Kubo from the University of Tokyo explained that "higher centres" of the bee's brain, known as the mushroom bodies, were more active in the brains of Japanese honeybees when they were a part of the "hot defensive bee ball". To find this out, the team lured the bees to form their ball by attaching a hornet to the end of a wire and inserting the predator into the hive. This simulated invasion caused the bees to swarm around the hornet. The researchers then plucked a few of the bees from the ball and measured, throughout each of their tiny brains, the relative amount of a chemical that is known to be a "marker" of brain activity. "We found that similar [brain] activity is evoked when the Japanese honeybees are simply exposed to high temperature (46C) in the laboratory," the researcher told BBC Nature. BBC © 2012

Keyword: Aggression
Link ID: 16526 - Posted: 03.17.2012

By Aimee Cunningham The chemical bisphenol A, known as BPA, has become familiar in the past decade, notably to parents searching for BPA-free bottles for their infants. Animal studies have found that BPA, which resembles the sex hormone estrogen, harms health. The growing brain is an especially worrisome target: estrogen is known to be important in fetal brain development in rodents. Now a study suggests that prenatal, but not childhood, exposure to BPA is connected to anxiety, depression and difficulty controlling behaviors in three-year-olds, especially girls. More than 90 percent of Americans have detectable amounts of BPA in their urine; for most people, the major source of exposure is diet. BPA is a component of the resins that line cans of food and the plastics in some food packaging and drink containers, and the chemical leaches into the edible contents. Other sources of BPA exposure include water-supply pipes and some paper receipts. Epidemiologist Joe M. Braun of Harvard University and his colleagues studied 240 women and their children in the Cincinnati area. The researchers collected urine samples from the mothers twice during pregnancy and within 24 hours of birth and from the children at ages one, two and three. BPA was detectable in 97 percent of the samples. They also surveyed parents about their kids’ behavior and executive functions—a term for the mental processes involved in self-control and emotional regulation. © 2012 Scientific American

Keyword: ADHD; Neurotoxins
Link ID: 16525 - Posted: 03.17.2012

By Marla Cone and Environmental Health News That is a main finding of a report, three years in the making, published Wednesday by a team of 12 scientists who study hormone-altering chemicals. Dozens of substances that can mimic or block estrogen, testosterone and other hormones are found in the environment, the food supply and consumer products, including plastics, pesticides and cosmetics. One of the biggest, longest-lasting controversies about these chemicals is whether the tiny doses that most people are exposed to are harmful. In the new report, researchers led by Tufts University's Laura Vandenberg concluded after examining hundreds of studies that health effects "are remarkably common" when people or animals are exposed to low doses of endocrine-disrupting compounds. As examples, they provide evidence for several controversial chemicals, including bisphenol A, found in polycarbonate plastic, canned foods and paper receipts, and the pesticide atrazine, used in large volumes mainly on corn. The scientists concluded that scientific evidence "clearly indicates that low doses cannot be ignored." They cited evidence of a wide range of health effects in people – from fetuses to aging adults – including links to infertility, cardiovascular disease, obesity, cancer and other disorders. "Whether low doses of endocrine-disrupting compounds influence human disorders is no longer conjecture, as epidemiological studies show that environmental exposures are associated with human diseases and disabilities," they wrote. © 2012 Scientific American

Keyword: Hormones & Behavior; Development of the Brain
Link ID: 16524 - Posted: 03.17.2012

By Cari Nierenberg A Dutch woman recovering from a stroke had an unusual response to seeing her family: The faces of her closest family members looked strange and distorted to her -- even repulsive. But at the same time, strangers' faces seemed normal. In fact, she had much less trouble recognizing the faces of strangers and celebrities than she did her own flesh and blood. This fascinating case of a 62-year-old woman referred to as JS is described in a recent issue of the journal Neurocase. Hospitalized after having an ischemic stroke, JS was unable to recognize one of her daughters with whom she had regular contact. But she immediately recognized her other daughter, whom she hadn't seen in eight years. When her grandchildren visited, she wouldn't let them sit on her lap because she thought they looked repulsive. "Of course, JS felt bad and ashamed about not recognizing family members or perceiving them as ugly," says Dr. Joost Heutink, the lead author of the case study. "As soon as we established that JS had a problem recognizing faces, we informed her family that a perceptual disorder prevented her from recognizing people she loved," he explains. Prosopagnosia. © 2012 msnbc.com

Keyword: Attention
Link ID: 16523 - Posted: 03.17.2012

By BENEDICT CAREY They were young males on the make, and they struck out not once, not twice, but a dozen times with a group of attractive females hovering nearby. So they did what so many men do after being repeatedly rejected: they got drunk, using alcohol as a balm for unfulfilled desire. Fruit flies apparently self-medicate just like many humans do, drowning their sorrows or frustrations for some of the same reasons, scientists reported Thursday. Male flies subjected to what amounted to a long tease — in a glass tube, not a dance club — preferred food spiked with alcohol far more than male flies that were able to mate. The study, posted online in the journal Science, suggests that some elements of the brain’s reward system have changed very little during evolution, and these include some of the mechanisms that support addiction. Levels of a brain chemical that is active in regulating appetite predicted the flies’ thirst for alcohol. A similar chemical is linked to drinking in humans. “Reading this study is like looking back in time, to see the very origins of the reward circuit that drives fundamental behaviors like sex, eating and sleeping,” said Dr. Markus Heilig, the clinical director of the National Institute on Alcohol Abuse and Alcoholism and the National Institute on Drug Abuse. Dr. Heilig, who was not involved in the research, said the findings also supported new approaches to treating alcohol dependence. Researchers are investigating several compounds aimed at blunting alcohol urges. © 2012 The New York Times Company

Keyword: Drug Abuse; Sexual Behavior
Link ID: 16522 - Posted: 03.17.2012

By Laura Sanders The eyes are a window to the soul, but also to the brain. The health of easy-to-check blood vessels in the retina reflects the health of blood vessels deep inside the head, findings that raise the possibility of a simple eye exam catching early signs of brain trouble, scientists report in the March 27 Neurology. “The potential is very great — to use the eye to diagnose what’s going on elsewhere in the body, particularly in the brain,” says neuroscientist Alistair Barber of Penn State College of Medicine in Hershey. “The retina is relatively easy to see. The brain is not.” The findings add to the growing number of studies focusing on blood vessels that link eye and brain health. The Neurology study was conducted as part of the Women’s Health Initiative, which tracks the health of postmenopausal women. Over 10 years, researchers led by epidemiologist and biostatistician Mary Haan of the University of California, San Francisco looked for a link between eye disease and brain performance in 511 women who were at least 65 years old. In the study, participants had their pupils dilated as researchers took pictures of their retinas. After careful examinations, 39 women, or 7.6 percent of the total, were found to have diseased blood vessels in the retina, a condition called retinopathy in which the vessels can become swollen, leaky or grow abnormally. Usually, retinopathy is a symptom of diabetes or high blood pressure, two disorders that if left untreated are known to affect brain functioning. © Society for Science & the Public 2000 - 2012

Keyword: Vision; Alzheimers
Link ID: 16521 - Posted: 03.17.2012

By Ferris Jabr Jason Egan does not walk, talk or eat like most nine-year-olds. He gets around in a wheelchair and depends on a feeding tube threaded into his stomach. He makes signs with his hands to communicate and has mustered the word "mom" on occasion. Although he cannot always articulate his feelings, he clearly feels a great deal. He is often seen smiling and laughing, especially when his father pushes him around the block near their home in Victoria, Australia. So far, no one has figured out exactly what is wrong with Egan. His doctors know that the boy's brain has been shrinking since birth, but he has tested negative for all known neurodegenerative disorders. Jason Egan may have a disease that is new to science. At first, Egan's doctors diagnosed him with cerebral palsy—an umbrella term for a group of related movement disorders. Children with cerebral palsy may have difficulty standing, moving, hearing, seeing and speaking. Their muscles are unusually tense and refuse to stretch, and their joints lock in place; some children experience tremors or seizures as well. In many cases, such children's brains were damaged during pregnancy or childbirth, usually in a way that limited oxygen to developing neurons. Symptoms of cerebral palsy may appear as early as three months—difficulty crawling, for instance—and usually make themselves known by age two. One of the defining features of cerebral palsy is that it is nonprogressive, which means that the severity of symptoms remains relatively constant over one's lifetime. Egan's symptoms, however, have changed over time. In 2009, around his sixth birthday, Egan began to lose what little sign language he had and stopped saying "mom." He started shaking and he did not seem to feel pain anymore, even when he injured himself. © 2012 Scientific American,

Keyword: Development of the Brain
Link ID: 16520 - Posted: 03.15.2012

by Peter Aldhous Just as many authors of the new psychiatry "bible" are tied to the drugs industry as those who worked on the previous version, a study has found, despite new transparency rules. The findings raise concerns over the independence of the revamped Diagnostic and Statistical Manual of Mental Disorders, or DSM, published by the American Psychiatric Association (APA) and scheduled for publication in May 2013. For the current rewrite, known as DSM-5, the APA for the first time required authors to declare their financial ties to industry. It also limited the amount they could receive from drug companies to $10,000 a year and their stock holdings to $50,000. "Transparency alone can't mitigate bias," says Lisa Cosgrove of Harvard University, who along with Sheldon Krimsky of Tufts University in Medford, Massachusetts, analysed the financial disclosures of 141 members of the "work groups" drafting the manual. They found that just as many contributors – 57 per cent – had links to industry as were found in a previous study of the authors of DSM-IV and an interim revision, published in 1994 and 2000 respectively. Cosgrove also points out that the $10,000-per-year limit on payments excludes research grants. "Nothing has really changed," she says. What's more, the work groups that had the most members with ties to the pharmaceutical industry were considering illnesses for which drugs are the front-line treatment – and for which proposed changes to diagnostic categories are especially controversial. © Copyright Reed Business Information Ltd.

Keyword: Schizophrenia; Depression
Link ID: 16519 - Posted: 03.15.2012

by Michael Marshall DON'T be offended, but you have the brain of a worm. Clusters of cells that are instrumental in building complex brains have been found in a simple worm that barely has a brain at all. The discovery suggests that, around 600 million years ago, primitive worms had the machinery to develop complex brains. They may even have had complex brains themselves - which were later lost. Vertebrates, such as humans and fish, have the biggest and most complex brains in the animal kingdom. Yet all their closest non-vertebrate relatives, such as the eel-like lancelets and sea squirts, have simple brains that lack the dozens of specialised nerve centres typical of complex brains. As a result, evolutionary biologists have long thought that complex brains only evolved after animals with backbones appeared. Not so, says Christopher Lowe of Stanford University in California. His team studies a species of acorn worm, Saccoglossus kowalevskii, which has a rudimentary nervous system made up of two nerve cords and nerves spread out in its skin. The worms live in burrows in the seabed and pull in passing particles of food. Lowe found that young S. kowalevskii have three clusters of cells identical to the ones vertebrates use to shape their brains. In developing vertebrate brains, these clusters - called signalling centres - make proteins that orchestrate the formation of specialised brain regions. The acorn worm, Lowe found, produces the same proteins, and they spread through its developing body in patterns similar to those they follow in the developing vertebrate brain (Nature, DOI: 10.1038/nature10838). © Copyright Reed Business Information Ltd.

Keyword: Evolution
Link ID: 16518 - Posted: 03.15.2012