New Haven, Conn.--Sensory deprivation causes changes in new cell size and excitability in the olfactory system, which governs the ability to smell, according to a study in Neuron by a Yale School of Medicine researcher. "This gives new insight into how stem cells in the olfactory system may be used to restore function in a brain that has been compromised by degenerative disease or trauma," said Gordon Shepherd, M.D., co-author of the paper and professor of neuroscience at Yale. Shepherd, on sabbatical with Pierre-Marie Lledo of the Pasteur Institute, investigated how the olfactory system responds to changes brought about by injury or different levels of activity. They closed one nostril in mice, a common sensory deprivation procedure, and then observed how the olfactory system adjusted to the change in sensory input. The olfactory system is one of the most plastic regions of the brain, with nerve cells that are continually replenished by stem cells. Stem cells in the nose replenish the sensory cells, which send the odor messages to the olfactory bulb. "There also are stem cells deep in the brain that replenish the interneurons, which carry out much of the processing of the odor messages that takes place in the olfactory bulb," Shepherd said.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 7157 - Posted: 04.07.2005

Researchers studying yeast cells have identified a metabolic enzyme as a potential therapeutic target for treating Huntington's disease, a fatal inherited neurodegenerative disorder for which there is currently no effective treatment. The group, whose results appear in the May issue of Nature Genetics, includes researchers from the University of Washington School of Medicine in Seattle and the University of Maryland School of Medicine in Baltimore. The paper was published online in advance at the journal's Web site, http://www.nature.com/ng/index.html. The group performed a genetic experiment known as a loss-of-function suppressor screen, which searches for genes that, when switched off, reduce the toxic effects of the mutant protein associated with Huntington's. One of the genes they identified encodes an enzyme, called KMO, that has been previously implicated in the disease. The enzyme functions in a metabolic pathway that is activated at early stages of the disease in people with Huntington's, as well as in animal models of the disease. "The nice thing about this finding is that there is a chemical compound available that inhibits KMO activity," said Dr. Paul Muchowski, assistant professor of pharmacology at the UW, who led the study. "We're in the midst of testing that compound in a mouse model of Huntington's disease." © 2005 University of Washington Office of News and Information

Keyword: Huntingtons
Link ID: 7156 - Posted: 06.24.2010

Long ago it may have been a lot easier for people to pass up extra food they didn't need sweet and salty foods like chips and cookies that so many of us crave. Scientists at the University of California, Davis have described for the first time how a protective brain mechanism, evolved long ago, makes sure animals eat a balanced diet of amino acids, the building blocks of protein, while turning from away foods they don't need. It's an ability that people may have once had, but is now lost to modern temptations. Getting enough amino acids is a priority for the body because they're essential to protein synthesis - the process that powers all the work our bodies do, like maintaining muscle tone, and repairing cuts - basically keeping us healthy. "If we don't have them in the diet or in our food the way we should," says lead researcher and professor of veterinary medicine Dorothy Giezten, "then we have to start breaking down our own body proteins." Scientists have known for decades that if an animal is deficient in any of the eight amino acids it needs to survive, it will reject foods that also lack those amino acids and search for other food. But until now, they never understood what controlled this choosy behavior. The researchers reported in the journal Science how a series of biochemical reactions runs this behavior in rats and mice. They say the reactions are identical to those seen in yeast, one of the world's simplest organisms, as well as in pigs, birds, and cats. Because so many different organisms share this mechanism, Giezten says it is second only to that which drives animals to eat when they are hungry. "It's so fundamental that it's conserved across all, what we call eukaryotic species, from all the way across evolution - from the simplest single cell organisms [like yeast], all the way up to people," says Gietzen. (C) ScienCentral, 2000-2005.

Keyword: Obesity
Link ID: 7155 - Posted: 04.07.2005

Genetic paternity tests have revealed that many apparently monogamous species indulge in infidelity, but scientists have puzzled over the benefits of these illicit liaisons. New research shows that, in the Seychelles warbler, the benefits are likely linked to genes associated with immune function. The Seychelles warbler is a songbird that inhabits a few small islands in the Indian Ocean's Seychelles group. On Cousin Island, breeding territories are in short supply, and females can't be too fussy about whom they choose as mates. But many make up for this lack of choice by having affairs: 40% of Cousin's warbler chicks are not fathered by their mother's mate. Reasoning that affairs might be a way for females to improve the genetic quality of their offspring, molecular ecologist David Richardson, of the University of East Anglia in Norwich, U.K., and colleagues investigated the relationship between female mate choice and the diversity of each individual's Major Histocompatibility Complex (MHC) genes. The MHC is a group of molecules which plays a major role in the body's immune response to pathogens. Studies in some species have shown that individuals with higher MHC diversity are better able to resist pathogens. The team found that there was indeed a relationship between MHC diversity and infidelity: Female warblers cheated far more frequently on males with below-average MHC diversity than on males with higher MHC diversity. Richardson says that the females don't appear to "sniff out" MHC characteristics the way mice do, so it may be that MHC diversity is associated with other features, such as superior singing or fighting, which make males more attractive or allow them to outcompete others. The team reports its findings in this week's online edition of Proceedings of the Royal Society B. Copyright © 2005 by the American Association for the Advancement of Science.

Keyword: Sexual Behavior; Evolution
Link ID: 7154 - Posted: 06.24.2010

Despite the divergent evolutionary paths of dolphins and primates -- and their vastly different brains -- both have developed similar high-level cognitive abilities, says Emory University neuroscientist and behavioral biologist Lori Marino. She presented her latest findings on the evolution of and differences in brain structure between cetaceans (ocean mammals like whales and dolphins) and primates April 5 during the 14th annual Experimental Biology 2005 meeting in San Diego. Marino's presentation examined the diverse evolutionary patterns through which dolphins and primates acquired their large brains, how those brains differ, and how sensory information can be processed in different ways and still result in the same cognitive abilities. "Eventually, a better understanding of how other species process information might be useful in helping people impaired in "human" ways of processing information. Perhaps there are alternative ways to sort out information in our own brains," says Marino, whose talk was part of the scientific sessions of the American Association of Anatomists.

Keyword: Evolution
Link ID: 7153 - Posted: 04.07.2005

A drug prescribed for the prevention of osteoporosis reduced women's risk of mild cognitive impairment by 33 percent in a worldwide clinical trial led by researchers at San Francisco VA Medical Center (SFVAMC). The drug, raloxifene, modulates the activity of the hormone estrogen. The finding was published in the April 2005 issue of the American Journal of Psychiatry. Mild cognitive impairment (MCI) affects more than one-third of women and one-fifth of men aged 65 and older. It reduces short-term memory and is associated with a significantly increased risk of Alzheimer's disease. "No other intervention has been proven to reduce the risk of mild cognitive impairment," says Kristine Yaffe, MD, the principal investigator of the trial. Yaffe is UCSF associate professor of psychiatry, neurology and epidemiology and chief of geriatric psychiatry at SFVAMC. Raloxifene is one of the most broadly prescribed drugs for the treatment of osteoporosis (it is also used to treat breast cancer). It is manufactured by Eli Lilly, which sponsored the trial, called the Multiple Outcomes of Raloxifene Evaluation (MORE). In the MORE trial, which took place at 180 clinical sites in 25 countries, 7,705 postmenopausal women with osteoporosis were randomly assigned to take a daily dose of either 120 milligrams of raloxifene, 60 milligrams of raloxifene, or a placebo for three years. Participants at 161 sites -- 7,023 women -- were measured for cognitive impairment at the beginning of the study and every year thereafter; cognitively impaired women were kept in the study.

Keyword: Alzheimers; Hormones & Behavior
Link ID: 7152 - Posted: 04.07.2005

HOUSTON -- – A study at Baylor College of Medicine in Houston may lead to a better understanding of how antidepressants like Prozac work – and how to make them more effective. According to results published in today's issue of the journal Neuron, a study in mice proposes that dopamine and serotonin neurotransmitter systems in the brain occasionally get their signals crossed, causing delays in stabilizing mood. "This study provides a new site for drug discovery in one of the biggest market for drugs – those that treat symptoms of depression," said Dr. John Dani, professor of neuroscience at BCM and lead author of the study. Dani's study, funded by the National Institutes of Health, offers an alternative explanation for the delayed effect of most antidepressants. "Some scientists thought that you had to take an antidepressant for weeks because as serotonin is elevated, some of its receptors had to turn off and become desensitized rather than be stimulated," Dani said. "That didn't make a lot of sense to us since desensitization is usually a rapid mechanism." Serotonin and dopamine neurotransmitter systems, which factor heavily in regulating mood, emotional balance, and psychosis, are released and reabsorbed in the striatum, an area of the brain which affects motivation and reward-based learning. Dani's findings indicate that these systems may be less selective and more "promiscuous" than previously believed.

Keyword: Depression
Link ID: 7151 - Posted: 06.24.2010

— French-led fossil hunters have fired the latest salvo in a battle over Toumai, a seven-million-year-old fossil that, they contend, is the earliest human ever found. Toumai came to the fore in 2002 when a team led by Michel Brunet of the University of Poitiers, central France, unveiled a nearly complete cranium, pieces of jawbone and several teeth that had been found in the Chadian desert. Animal remains in the earth layers in which these pieces were found indicated the age at up to seven million years, making Toumai the earliest known hominid, or forerunner of Homo sapiens, ever discovered. But the claim triggered dismay in Ethiopia and Kenya — the countries of the Great Rift Valley where humankind is commonly believed to have emerged — as well as rebuttals from within the palaeontology community, which beneath its placid veneer can be viciously competitive. Critics said that Toumai's cranium was too squashed to be that of a hominid — it did not have the brain capacity that gives humans primacy — and its small size indicated a creature of no more than 120 centimetres (four feet) in height, about the size of a walking chimp. Copyright © 2005 Discovery Communications Inc.

Keyword: Evolution
Link ID: 7150 - Posted: 06.24.2010

PORTLAND, Ore. -- Researchers at Oregon Health & Science University's Neurological Sciences Institute (NSI) have shed light on the brain cell damage caused by Alzheimer's disease. The researchers hope that by gaining a better understanding of the disease's cellular impacts, progress can be made towards developing a treatment. The research is reported in the current edition of the Journal of Alzheimer's Disease, published by IOS publishers. While the cognitive and behavioral impacts of Alzheimer's can be clearly witnessed in patients, the disease's cellular function and methods for disrupting thought and memory have not been well understood. By conducting this research, NSI scientists and their collaborators have demonstrated how proteins involved in brain cell communications, called synaptic proteins, decrease in the brains of Alzheimer's patients when compared to healthy brains from people in the same age range. "More importantly, we found that the decrease of synaptic protein levels in the frontal cortex of the brains of Alzheimer's patients was more severe than in other portions of the brain," explained P. Hemachandra Reddy, Ph.D., scientist at the Neurological Sciences Institute and first and corresponding author of the paper. "Because the frontal cortex is home to important brain functions such as reasoning, planning, and abstract thought – all affected by Alzheimer's – this finding appears to be significant. Furthermore, we noticed that synaptic protein levels were even lower in the brains of patients in the early stages of Alzheimer's disease. This suggests to us that the loss of these important proteins happens very early in the disease process."

Keyword: Alzheimers
Link ID: 7149 - Posted: 06.24.2010

Roxanne Khamsi A compound derived from the cannabis plant protects blood vessels from dangerous clogging, a study of mice has shown. The discovery could lead to new drugs to ward off heart disease and stroke. The compound, called delta-9-tetrahydrocannabinol (THC), combats the blood-vessel disease atherosclerosis in mice. This disease occurs when damage to blood vessels, by nicotine from cigarettes, for example, causes an immune response that leads to the formation of fatty deposits in arteries. These deposits form because the immune cells can linger too long, recruiting others and leading to an inflamed blockage that snares fatty molecules. The disease is the leading cause of heart disease and stroke in the developed world. THC seems to tone down this immune response, report François Mach of the University Hospital Geneva, Switzerland and his colleagues. The compound binds to a protein called CB2 that is present on the surfaces of certain immune cells. ©2005 Nature Publishing Group

Keyword: Drug Abuse; Stroke
Link ID: 7148 - Posted: 06.24.2010

Women undergoing IVF treatment are much less likely to succeed if they smoke, according to a large Dutch study. The effect of smoking on fertility was found to be so pronounced that it was equivalent of adding more than 10 years to a woman’s reproductive age. “Our study found that the effect of smoking more than one cigarette a day for a year reduced women’s chances of having a live birth through IVF by 28% - that’s the same percentage disadvantage that occurs between a 20-year-old woman and a 30-year-old woman,” says Didi Braat, professor of gynaecology at the University Medical Centre in Nijmegen, where the study was carried out. Braat and colleagues analysed medical data and questionnaire responses from nearly 8500 women aged 20 to 45, who had undergone IVF treatment at centres in The Netherlands between 1983 and 1995. More than 40% of the women were smokers and at least 7% were overweight - with a body mass index of 27kg/m2 or higher - at the time of their first IVF attempt. The women’s subfertility was attributed to one of four causes: fallopian tube problems, male partner subfertility, unexplained subfertility and other causes - mainly polycystic ovarian syndrome or endometriosis. “Smoking had the greatest effect on those women with unexplained fertility problems, where IVF treatment led to 20.7% of non-smokers achieving a live birth, compared with just 13.4% of smokers,” says Braat. “These results indicate that smoking may actually be causing the infertility problems these women were experiencing.” © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse
Link ID: 7147 - Posted: 06.24.2010

US scientists have designed a bionic eye to allow blind people to see again. It comprises a computer chip that sits in the back of the individual's eye, linked up to a mini video camera built into glasses that they wear. Images captured by the camera are beamed to the chip, which translates them into impulses that the brain can interpret. The device has been designed by Professor Gislin Dagnelie at Johns Hopkins University, Baltimore. Professor Dagnelie unveiled details at a Royal National Institute for the Blind conference in London on Monday. Human trials will begin within a year, hopes Professor Dagnelie. Although the images produced by the artificial eye are far from perfect, they could be clear enough to allow someone who is otherwise blind to recognise faces, he said. The breakthrough is likely to benefit patients with the most common cause of blindness, macular degeneration, which affects 500,000 people in the UK. This occurs when there is damage to the macular, which is in the central part of the retina where light is focussed and changed into nerve signals in the middle of the brain. The implant bypasses the diseased cells in the retina and stimulates the remaining viable cells. (C)BBC

Keyword: Vision; Robotics
Link ID: 7146 - Posted: 04.05.2005

By BENEDICT CAREY The debate over Terri Schiavo's fate comes at a time when researchers are deepening their understanding of the unconscious brain. Neuroscientists now understand at least some of the physiology behind a wide range of unconscious states, from deep sleep to coma, from partially conscious conditions to a persistent vegetative state, the condition diagnosed in Ms. Schiavo. New research, by laboratories in New York and Europe, has allowed for much clearer distinctions to be made between the uncounted number of people who at some time become comatose, the 10,000 to 15,000 Americans who subsist in vegetative states and the estimated 100,000 or more who exist in states of partial consciousness. This emerging picture should make it easier for doctors to judge which brain-damaged patients have some hope of recovering awareness, experts say, and already it is providing clues to the specific brain processes that sustain conscious awareness. "Understanding what these processes are will give us a better sense of how to help the whole range of people living with brain injuries," said Dr. Nicholas Schiff, an assistant professor of neurology and neuroscience at NewYork-Presbyterian/Weill Cornell hospital. "That is where this field is ultimately headed: toward a better understanding of what consciousness is." Copyright 2005 The New York Times Company

Keyword: Miscellaneous
Link ID: 7145 - Posted: 04.05.2005

By CARL ZIMMER The inland taipan, a nine-foot-long Australian snake, is not the sort of creature most people would want to bother. Drop for drop, its venom is the deadliest in the world, 50 times as potent as cobra venom. Its fangs are so long they can poke through the snake's lower jaw. Its victims collapse in seconds and suffer a quick death. Dr. Bryan Fry, a biologist from the University of Melbourne, will readily admit he is not like most people. He not only bothers inland taipans; he hunts them down in dense cane fields, pins them down and bags them. Later he grabs them by the head and squeezes venom from their fangs. Besides inland taipans, Dr. Fry collects venom from death adders, rattlesnakes, king cobras, sea snakes and many others. He estimates that he handles 2,000 to 3,000 snakes a year. "Working with some of these snakes is the biggest adrenaline rush you could ever do," he admitted. "I used to do extreme ski jumping and big wave surfing, but none of that can touch working with some of these animals." Copyright 2005 The New York Times Company

Keyword: Neurotoxins
Link ID: 7144 - Posted: 04.05.2005

PHILADELPHIA – Cognitive therapy to treat moderate to severe depression works just as well as antidepressants, according to an authoritative report appearing today in the Archives of General Psychiatry. The study, conducted by researchers at the University of Pennsylvania and Vanderbilt University, challenges the American Psychiatric Association's guidelines that antidepressant medications are the only effective treatment for moderately to severely depressed patients. Either form of treatment worked significantly better than a placebo, but the researchers demonstrated that cognitive therapy was more effective than medication at preventing relapses after the end of treatment. "We believe that cognitive therapy might have more lasting effects because it equips patients with the tools they need to learn how to manage their problems and emotions," said Robert DeRubeis, professor and chair of Penn's Department of Psychology. "Pharmaceuticals, while effective, offer no long term cure for the symptoms of depression. For many people, cognitive therapy might prove to be the preferred form of treatment." The study, which follows years of debate on the relative merits of cognitive therapy versus medication for more severe forms of depression, is the largest trial yet undertaken on the topic; it involved 240 depressed patients. The patients were randomly placed into groups that received cognitive therapy, antidepressant medication or a placebo. Patients in the antidepressant group, which was twice as large as the other two, were treated with paroxetine (Paxil). Lithium or desipramine was also given, as necessary.

Keyword: Depression
Link ID: 7143 - Posted: 06.24.2010

Despite the efforts of advocates such as the late Christopher Reeve pushing for more research to find a cure for spinal cord injuries, international research efforts have been slow to progress out of the lab and into the clinic. According to the Institute of Medicine (IOM) report, neither the scientific community nor thousands of Americans who have been paralyzed by spinal cord injuries are happy with the limited treatment options currently available. The report points out "an obvious and urgent need to identify and test new interventions and to accelerate the pace of research." "We're talking about a burden here of about 11 thousand new cases a year in this country," says Jeremiah Barondess, President of the New York Academy of Medicine, who served on the IOM committee that produced the report. "It?s a tremendous tragedy, a quarter of a million people are living in the U.S. with chronic spinal injury." The last few decades of research have led to significant progress in the field, improving patient survival and rehabilitation options, as well as emergency medical treatment. Additionally, recent advances in neuroscience research are opening up new opportunities for the development of therapeutic approaches. "I think the field is poised now for really striking advances because of what's been learned in neurobiology in the last ten or a dozen years," Barondess says. (C) ScienCentral, 2000-2005.

Keyword: Regeneration
Link ID: 7142 - Posted: 04.05.2005

EVANSTON, Ill. --- Learning disabilities such as dyslexia are believed to affect nearly one in 10 children. To better study them, a Northwestern University research team has developed a data-driven conceptual framework that links two well-established scientific concepts. In doing so, they also have developed a non-invasive diagnostic tool called BioMAP that can quickly identify children with learning disabilities. Scientists have long recognized that children who can best process various aspects of the sounds of language are more likely to read earlier and develop into better readers and writers than those who cannot. After a decade of research, Northwestern Professor Nina Kraus and her colleagues have discovered a subset of learning disabilities that results from a dysfunction in the way the brainstem encodes certain basic sounds of speech. In an article in the April "Trends in Neurosciences," Kraus, who is Hugh Knowles Professor of Communication Sciences and Neurobiology, and senior research analyst Trent Nicol for the first time ever have linked the source-filter model of acoustics with the cerebral cortex's "what" and "where" pathways via the auditory brainstem.

Keyword: Dyslexia
Link ID: 7141 - Posted: 04.05.2005

CHAPEL HILL -- A study commissioned by the American Psychiatric Association and led by a psychiatrist at the University of North Carolina at Chapel Hill School of Medicine has found that light therapy effectively treats mood disorders, including seasonal affective disorder (SAD) and other depressive disorders. A report of the study, which appeared April 1 in the American Journal of Psychiatry, also finds that the effects of light therapy, also known as phototherapy, are comparable to those found in many clinical studies of antidepressant drug therapy for these disorders. The findings were based on a meta-analysis, a systematic statistical review of 20 randomized, controlled studies previously reported in the scientific literature. These represented only 12 percent of 173 published studies that the authors had originally considered for review. "We found that many reports on the efficacy of light therapy are not based on rigorous study designs. This has fueled the controversy in the field as to whether or not light therapy is effective for SAD or for non-seasonal forms of mood disorders," said lead author Dr. Robert Golden, professor and chairman of psychiatry at UNC and vice dean of the medical school.

Keyword: Depression; Biological Rhythms
Link ID: 7140 - Posted: 04.05.2005

New York, NY, --- A new brain imaging study of recently diagnosed schizophrenia patients has found, for the first time, that the loss of gray matter typically experienced by patients can be prevented by one of the new atypical antipsychotic drugs, olanzapine, but not by haloperidol, an older, conventional drug. The study, published in today's Archives of General Psychiatry, also confirmed previous studies that show patients who experience less brain loss do better clinically. "This is a really big breakthrough," says the study's leader, Jeffrey Lieberman, M.D., director of the New York State Psychiatric Institute and chairman of psychiatry at Columbia University Medical Center. "The drugs we have for schizophrenia can't cure people who've been sick for years, but this study shows that the newer atypical drugs, if started early, can prevent the illness from progressing. If our findings are confirmed, one could argue that we should treat new patients with atypical drugs like olanzapine rather than older conventional medications such as haloperidol and chlorpromazine." Gray matter contains the bulk of the brains cell's and the billions of connections among the cells. Loss of gray matter in patients with schizophrenia has been linked to social withdrawal and progressive deterioration in cognition and emotion--which are among the least responsive symptoms to medications.

Keyword: Schizophrenia
Link ID: 7139 - Posted: 04.05.2005

Young children who watch a lot of television are more likely to become bullies, a new study reveals. The authors suggest the increasingly violent nature of children’s cartoons may be to blame. Previous studies have linked television to aggressive behaviour in older children and adolescents. But a team led by Frederick Zimmerman, an economist at the University of Washington in Seattle, US, has now traced the phenomenon to four-year-olds. The researchers used existing data from a national US survey to study the amount of television watched by 1266 four-year-olds. Then they compared that amount with follow-up reports - by the children's mothers - on whether the children bullied or were "cruel or mean to others" when they were between six and 11 years old. The study showed that four-year-olds who watched the average amount of television - 3.5 hours per day - were 25% more likely to become bullies than those who watched none. And children who watched eight hours of television a day were 200% more likely to become bullies. The study did not probe what types of programmes the children were watching, but Zimmerman suggests they were mainly animated videos and cartoons. He says such shows may follow a trend seen in movies and cites a recent study showing the average G-rated kids' movie contains (U-rated in the UK) about 9.5 minutes of violence - up from 6 minutes in 1940. © Copyright Reed Business Information Ltd.

Keyword: Aggression
Link ID: 7138 - Posted: 06.24.2010