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

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

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

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

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

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

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

Keyword: Schizophrenia
Link ID: 8386 - Posted: 06.24.2010

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

Keyword: Aggression
Link ID: 8385 - Posted: 01.12.2006

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

Keyword: Sleep
Link ID: 8384 - Posted: 06.24.2010

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

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

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

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

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

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

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

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

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

Keyword: Hearing
Link ID: 8379 - Posted: 06.24.2010

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

Keyword: Vision
Link ID: 8378 - Posted: 01.11.2006

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

Keyword: Alzheimers
Link ID: 8377 - Posted: 06.24.2010

Lab experiments suggest that a pregnant mother's exposure to certain chemicals in the environment can cause reproductive problems not only for her own children, but also for several more generations of her family. As this ScienCentral News video explains, research with pregnant rats revealed what genetics researchers thought was impossible. One chemical is used in insecticides. The other is a fungicide used on vineyards and orchards. They are known to alter levels of reproductive hormones, but there were no signs — until now — that such chemicals could alter our genes — the DNA code we pass on to our children. "We've made a discovery that has made us sit back and think about some general biology questions in a number of different areas," says biologist Michael Skinner, director of Washington State University's Center for Reproductive Biology. "If disease can be induced by environmental factors, and then subsequently be carried forward to the subsequent generations, then we have come up with potentially a new paradigm for disease development." When Skinner gave high doses of the chemicals to pregnant rats, he discovered sperm count problems in 90 percent of all male descendants over the next four generations. Something he calls a "transgenerational phenomenon." © ScienCentral, 2000-2006.

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 8376 - Posted: 06.24.2010

A team of researchers, led by investigators at Washington University School of Medicine in St. Louis, has found that a gene variant for a bitter-taste receptor on the tongue is associated with an increased risk for alcohol dependence. The research team studied DNA samples from 262 families, all of which have at least three alcoholic individuals. The families are participating in a national study called the Collaborative Study of the Genetics of Alcoholism (COGA). COGA investigators report in the January issue of the American Journal of Human Genetics on the variation in a taste receptor gene on chromosome 7 called TAS2R16. "In earlier work, we had identified chromosome 7 as a region where there was likely to be a gene influencing alcoholism risk," says principal investigator Alison M. Goate, D. Phil., the Samuel and Mae S. Ludwig Professor of Genetics in Psychiatry at Washington University. "There's a cluster of bitter-taste receptor genes on that chromosome, and there have been several papers suggesting drinking behaviors might be influenced by variations within taste receptors. So we decided to look closely at these taste receptor genes." Because taste receptors tend to vary a lot in the general population, Goate and colleagues had the opportunity to look at a large number of differences in genetic sequences and determine whether certain sequences might influence risk. In this study, they concentrated on TAS2R16, which helps regulate the response to bitter tastes. They found a single base variation in the TAS2R16 receptor gene that seemed to put people at an increased risk for alcoholism. In cell culture experiments, Goate found that the variant receptor produced by this gene was less responsive to bitter compounds.

Keyword: Chemical Senses (Smell & Taste); Drug Abuse
Link ID: 8375 - Posted: 01.11.2006

By Amy R. Coombs As anyone on a new year's diet can attest, gaining weight is much easier than burning it off. Humans aren't the only ones capable of packing on the pounds, however. New research indicates that insects store fat in one of the same ways mammals do. Identifying the fat management pathways insects and mammals have in common may eventually help scientists develop new ways to fight obesity, say the researchers. Fat cells form when a unique class of stem cells make a critical decision: They either become osteoblasts, which develop into bone cells, or preadipocytes, which give rise to fat cells. Exactly which messages tell a stem cell to become a fat cell rather than a bone cell remain a mystery, however. To learn more about the process, Jonathan Graff, a molecular biologist at the University of Texas Southwestern Medical Center in Dallas, studied a set of genes known to impact development in humans, flies, and many other animals. To see if the set, called the Hedgehog suite, also influences the development of fat cells, Graff and his research team bred mutant flies missing select Hedgehog genes. Flies without the genes were fatter, survived starvation better, and had higher overall levels of lipid and fat related proteins than did flies with an intact gene suite, the team reports this month in Cell Metabolism. © 2006 American Association for the Advancement of Science.

Keyword: Obesity
Link ID: 8374 - Posted: 06.24.2010

Researchers at Rutgers, The State University of New Jersey, believe they have located a place in the brain where songbirds store the memories of their parents' songs. The discovery has implications for humans, because humans and songbirds are among the few animals that learn to vocalize by imitating their caregivers. In a paper published today in the Proceedings of the National Academy of Sciences, David Vicario and Mimi Phan of Rutgers, and Carolyn Pytte of Wesleyan University, report that songbirds store the memory of caregivers' songs in a part of the brain involved in hearing. This suggests the auditory version of the caregiver's song is stored first, and that it may serve to guide the vocal learning process. The paper is titled "Early Auditory Experience Generates Long-Lasting Memories That May Subserve Vocal Learning in Songbirds." "There is independent evidence, notably from work done by Patricia Kuhl of the University of Washington in Seattle, that something similar may underlie the acquisition of human speech by infants and, thus, be part of the mechanism that allows kids to learn any human language if they start early enough," Vicario says. Vicario, Phan and Pytte worked with zebra finches, tiny songbirds native to Australia and favored by researchers because they breed well in captivity and all year- round. There are other animals that also learn vocalizations by imitating members of their species – whales, dolphins and parrots, for instance – but they take a long time to mature, are endangered or are too difficult to work with in laboratories.

Keyword: Language; Sexual Behavior
Link ID: 8373 - Posted: 06.24.2010

Helen Pearson If you're the type to stumble about as though drunk on first getting out of bed, scientists can now back up your behaviour as reasonable. A team has shown that people are as woozy when they wake as they are after drinking several beers. Sleep researchers have long been interested in the symptoms of sluggishness and disorientation that people experience after awakening, which they call sleep inertia. Now they have measured exactly how hopeless our early-morning brains are at carrying out everyday tasks. To do this, Kenneth Wright at the University of Colorado, Boulder, and his co-workers looked at the mental handicap caused by sleep inertia, and compared it with the detriment of having stayed up all night. They allowed nine volunteers to enjoy roughly eight hours' nightly slumber for four weeks, the final week taking place in the lab. After a final pleasant night's sleep, they woke each person and immediately, without even a cup of coffee, asked them to calculate a string of sums. A minute after waking, they scored how many problems each one totted up correctly over two minutes. The test was then repeated after 20 minutes and again at regular intervals until the subjects had gone a full 26 hours without sleep. ©2006 Nature Publishing Group

Keyword: Sleep
Link ID: 8372 - Posted: 06.24.2010

By Eric Jaffe "If we find any gross abnormalities in your brain, would you like a radiologist to tell you about it?" Tobias Egner asks me. He is about to wheel me into the dark gullet of an fMRI machine at the Functional MRI Research Center at Columbia University, a leading neuroscience lab where he is a research fellow. I say yes to his question and ask if anyone ever says no. "If you answer no, we cannot do the test," Egner says. He speaks with a soft certainty and a German accent; if this were a movie, he'd be played by Willem Dafoe, a la The Life Aquatic With Steve Zissou. "Ready to roll?" In the last decade, fMRI (or functional magnetic resonance imaging) has become a premier—and scrutinized—tool of neuroscience. I wanted to see for myself how the technology works. On a visit to Columbia's lab to view an experiment, I mentioned an interest in participating, and two researchers within earshot accepted my offer. I signed on with Egner to become one of about 20 subjects in a study of how the brain manages conflicting information. To me, this means choosing every night at 7 between the Seinfeld rerun on Fox and the one on TBS. To Egner, it means studying how the amygdala, the brain's emotional hub, resolves the millions of emotional conflicts people experience every day. To watch my mind in action, Egner will use the fMRI machine's magnetic coil to scan my brain every two seconds for blood rushes, which show an increase in neural activity. The more common MRI uses magnetic resonance imaging to scan the body for abnormal tissue, in order to diagnose a tumor or an injury. The added "f" for functional means the machine will look at my brain while I perform mental tasks, so it can see which regions are most active. From a control room facing me, Egner will capture the results on a computer. ©2005 Washingtonpost.Newsweek Interactive Co. LLC

Keyword: Brain imaging
Link ID: 8371 - Posted: 06.24.2010

By Ker Than A new study finds that a cell once believed to serve neurons instead may perform the crucial function of regulating blood flow in the brain. The discovery challenges a basic assumption in neuroscience and could have implications for interpreting brain scans and understanding what occurs during brain trauma and Alzheimer's disease. Oxygen is the main fuel of biological cells. It is transported throughout the body by way of the circulatory system. Not surprisingly, the brain is one of the most voracious consumers of oxygen, and a basic assumption in neuroscience is that the more active a brain region is, the more oxygen (and thus blood) its neurons require. This assumption forms the foundation for sophisticated brain imaging techniques such as PET and functional MRI scans. By scanning the brain while subjects perform certain tasks, scientists have been able to pinpoint specialized brain regions for phenomena such as emotion or language. Star-shaped brain cells called astrocytes were traditionally thought of as housekeeping cells that helped nourish the brain under the direction of the neurons. The new study found that the astrocytes can directly control blood flow without being told. 2006 LiveScience.com.

Keyword: Glia; Brain imaging
Link ID: 8370 - Posted: 01.11.2006