Christen Brownlee In the stoner stereotype, pot smokers and dying brain cells go hand in hand. However, new research suggests the situation may be more uplifting than that. A drug that functions as concentrated marijuana does may spur neurogenesis, the process by which the brain gives birth to new nerve cells. Previous research had suggested that neurogenesis happens only in select locations in the brain, such as the hippocampus, a region involved in learning and memory. Some studies have shown that this process is inhibited by most illicit drugs, such as cocaine, heroin, and methamphetamine. However, says Xia Zhang of the University of Saskatchewan in Saskatoon, marijuana's effect on neurogenesis has not been clear. He and his colleagues started investigating this mystery by searching cell surfaces in live, cultured slices of rat hippocampus for receptors that respond to marijuana and a few other similar drugs, called cannabinoids. They reasoned that if marijuana affected neurogenesis in the hippocampus, then cells in that area must have a way to recognize the drug. Sure enough, 95 percent of hippocampus cells responsible for neurogenesis showed evidence of cannabinoid 1 (CB1) receptors, one of two receptors that respond to cannabinoid drugs. ©2005 Science Service.

Keyword: Drug Abuse; Neurogenesis
Link ID: 8035 - Posted: 06.24.2010

By Marc Kaufman, Washington Post Staff Writer Pharmacies in black neighborhoods are much less likely to carry sufficient supplies of popular opioid painkillers than those in white neighborhoods, a new study has found, leading researchers to conclude that minorities are routinely undertreated for chronic pain. The study found that the disparity between what is available to patients in majority-black neighborhoods compared with majority-white areas had little to do with income levels, as pharmacies in wealthy black neighborhoods were no more likely to carry the prescription painkillers than those in poorer black neighborhoods. In wealthy white neighborhoods, however, pharmacies were far more likely to carry sufficient stock than in poor white communities. "The pharmacies in minority areas generally say they stock limited amounts of pain medication because the demand is not there," said Carmen R. Green, an associate professor at the University of Michigan Medical School, who led the research. "But the low-demand barrier does not ring true for me," she said. "We know that minorities are more at risk of suffering chronic pain, and maybe they don't come to local pharmacies because they've come to expect they won't carry the medicines they need." © 2005 The Washington Post Company

Keyword: Pain & Touch; Drug Abuse
Link ID: 8034 - Posted: 06.24.2010

By Christof Koch The brain is an amazingly dynamic organ. Millions of neurons in all corners of our gray matter send out an endless stream of signals. Many of the neurons appear to fire spontaneously, without any recognizable triggers. With the help of techniques such as electroencephalography (EEG) and microelectrode recordings, brain researchers are listening in on the polyphonic concert in our heads. Any mental activity is accompanied by a ceaseless crescendo and diminuendo of background processing. The underlying principle behind this seeming racket is not understood. Nevertheless, as everyone knows, the chaos creates our own unique, continuous stream of consciousness. And yet it is very difficult to focus our attention on a single object for any extended period. Our awareness jumps constantly from one input to another. No sooner have I written this sentence than my eyes move from the computer screen to the trees outside my window. I can hear a dog barking in the distance. Then I remember the deadline for this article--which isn't going to be extended again. Resolutely, I force myself to type the next line. How does this stream of impressions come to be? Is our perception really as continuous as it seems, or is it divided into discrete time parcels, similar to frames in a movie? These questions are among the most interesting being investigated by psychologists and neuroscientists. The answers will satisfy more than our curiosity--they will tell us if our experience of reality is accurate or a fiction and if my fiction is different from yours. © 1996-2005 Scientific American, Inc

Keyword: Vision
Link ID: 8033 - Posted: 06.24.2010

With around 64 percent of the population is either overweight or obese, health issues relating to being overweight have become almost epidemic in the U.S. Obesity causes "metabolic syndrome" — in which insulin-resistance leads to diabetes, heart disease and other aging diseases. Meanwhile, it's been observed that throughout the animal kingdom, animals from worms to mice to monkeys live longer, healthier lives when eating very low calorie diets. Anti-aging researchers say the evidence all shows that metabolic function is closely linked to the aging process. "Just reducing intake of calories has so many positive effects and we'd like to find the switches," says geneticist Stephen Spindler, professor of biochemistry at the University of California at Riverside. "There must be relatively few switches that that throws to cause us to change from a rapid aging, higher-disease state to a slower aging lower-disease state." As reported in Discover magazine, some biotech companies like Massachusetts-based Elixir Pharmaceuticals, want to design new drugs to mimic those effects. But Elixir researchers also predict that some already widely-used drugs may turn out to slow aging. "There are indeed medicines that are currently available that treat metabolic function that probably have a positive effect on lifespan," says Bill Heiden, Elixir President and CEO. © ScienCentral, 2000-2005

Keyword: Obesity
Link ID: 8032 - Posted: 06.24.2010

Andreas von Bubnoff The protein particles that cause illnesses such as mad cow disease can be found in the urine of infected mice, researchers report. Their study may solve the mystery of how such 'prion' diseases spread among animals such as sheep, elk and deer. But it also raises concerns that the urine of humans with new-variant Creutzfeldt-Jakob disease (vCJD) may contain dangerous proteins. Prions are primarily found in the brain, the spinal cord and the immune system. British cows are thought to have developed the prion disease bovine spongiform encephalopathy (BSE) by eating ground-up brains, spleens and similar material. Other body parts were thought to be relatively safe for consumption. Then, in 2003, Adriano Aguzzi's group at the University Hospital of Zurich, Switzerland, found prions in the muscle tissue of people who had died from a brain wasting disease. And this January, the team showed in mice that prions also spread to the pancreas, kidneys and liver if there is inflammation in these organs. Together, these findings suggested that the brain and lymphatic organs might not be the only dangerous ones. ©2005 Nature Publishing Group

Keyword: Prions
Link ID: 8031 - Posted: 06.24.2010

A synthetic chemical similar to the active ingredient in marijuana makes new cells grow in rat brains. What is more, in rats this cell growth appears to be linked with reducing anxiety and depression. The results suggest that marijuana, or its derivatives, could actually be good for the brain. In mammals, new nerve cells are constantly being produced in a part of the brain called the hippocampus, which is associated with learning, memory, anxiety and depression. Other recreational drugs, such as alcohol, nicotine and cocaine, have been shown to suppress this new growth. Xia Zhang of the University of Saskatchewan in Saskatoon, Canada, and colleagues decided to see what effects a synthetic cannabinoid called HU210 had on rats' brains. They found that giving rats high doses of HU210 twice a day for 10 days increased the rate of nerve cell formation, or neurogenesis, in the hippocampus by about 40%. A previous study showed that the antidepressant fluoxetine (Prozac) also increases new cell growth, and the results indicated that it was this cell growth that caused Prozac’s anti-anxiety effect. Zhang wondered whether this was also the case for the cannabinoid, and so he tested the rats for behavioural changes. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse; Neurogenesis
Link ID: 8030 - Posted: 06.24.2010

Researchers have identified the first gene mutation associated with Tourette syndrome - opening a new avenue for understanding the complex disorder that causes muscle and vocal tics. Until now, causes of Tourette syndrome (TS), which afflicts as many as 1 in 100 people, have eluded researchers because the disease appears to be caused by subtle mutations in many genes. The researchers published their findings in the October 14, 2005, issue of the journal Science. Matthew W. State of the Yale University School of Medicine was senior author of the paper. His research was supported by a Howard Hughes Medical Institute institutional award to Yale that was used to support early research by promising scientists at Yale. According to State, early theories suggesting that a single gene mutation causes TS have proven incorrect. “There has been an evolving hypothesis about Tourette syndrome being a much more complex disorder,” State said. “I think there is general consensus at this point that there are likely to be multiple genes, likely interacting, and probably different sets of genes in different people, that contribute to TS.” The notion of multiple genes is borne out by the complex phenotype of the syndrome, which is often associated with obsessive-compulsive disorder, attention deficit hyperactivity disorder, or depression, said State. © 2005 Howard Hughes Medical Institute.

Keyword: Tourettes
Link ID: 8029 - Posted: 06.24.2010

BY FRED BORTZ Even staunch supporters of Darwinian evolution understand why many people find that theory hard to accept. We see ourselves as endowed with an intellect and culture (and, some would say, a soul) that set us apart from all other creatures. We are rational beings, while apes behave like -- well -- animals. And if scientific evidence persuades us that we are indeed evolved from apes, then surely we are more highly evolved than orangutans, gorillas, chimpanzees, and bonobos. Frans de Waal, an Emory University primatologist, would not agree. Those species are as highly evolved as our own. Their evolution simply followed different tracks. If we really want to understand what makes us human, de Waal argues in Our Inner Ape, we should not focus on our differences from apes, but rather examine the "fascinating and frightening parallels between primate behavior and our own, with equal regard for the good, the bad, and the ugly." That is precisely what he does in this book, with a wealth of stories and an entertaining style that does not sacrifice scientific depth or objectivity. He focuses on chimpanzees and bonobos because they are closest to humans, sharing a common ancestor as recently as 5.5 million years ago. After humans branched off, ancestral chimps and bonobos remained a single species for 3 million more years. Genetic evidence indicates that humans are more closely related to bonobos than to chimps, but only slightly so. Copyright 2005, Digital Chicago Inc

Keyword: Evolution; Sexual Behavior
Link ID: 8028 - Posted: 10.13.2005

We all need shut-eye, but some of us sleep much more soundly than others. Now, researchers have found a gene that appears to determine how intensely we sleep. When it comes to getting a good night's rest, not all sleep is the same. The most important stage of the sleep cycle is deep sleep--also known as slow wave sleep--the slumber where the brain's electrical activity is at its slowest. Even after only a few nights deprived of these roughly hour-long plunges into nothingness, body temperature and immune functions become unstable. In spite of its importance, not everyone gets the same amount of deep sleep, and studies of twins indicate that some of this variation is genetic. In mice, differences in sleep quality have been linked to a collection of genes regulating the neurotransmitter adenosine. (Adenosine is part of the pathway that caffeine inhibits to keep us awake.) Researchers studying rats found that the amount of deep sleep could be increased by chemically interfering with one of these adenosine-regulating genes, called adenosine deaminase (ADA). To see whether ADA plays a role in human sleep quality, a team led by Hans-Peter Landolt, a sleep physiologist at the University of Zurich, Switzerland, sequenced the gene in 119 student volunteers and hosted them for three nights of sleep in the lab. A tiny difference in DNA translates to a big improvement in sleep quality. Ten percent of the volunteers, who had a mutation in ADA, enjoyed about half an hour more deep sleep, as measured by electrical activity in the brain, than volunteers without the mutation, the team reports online this week in Proceedings of the National Academies of Science. Copyright © 2005 by the American Association for the Advancement of Science.

Keyword: Sleep
Link ID: 8027 - Posted: 06.24.2010

EAST LANSING, Mich. – A Michigan State University researcher and his colleagues have shown that playing violent video games leads to brain activity pattern that may be characteristic for aggressive thoughts. In a functional magnetic resonance imaging (fMRI) study, 13 male research participants were observed playing a latest-generation violent video game. Each participant’s game play was recorded and content analyzed on a frame-by-frame basis. “There is a causal link between playing the first-person shooting game in our experiment and brain-activity pattern that are considered as characteristic for aggressive cognitions and affects,” said René Weber, assistant professor of communication and telecommunication at MSU and a researcher on the project. “There is a neurological link and there is a short-term causal relationship. “Violent video games frequently have been criticized for enhancing aggressive reactions such as aggressive cognitions, aggressive affects or aggressive behavior. On a neurobiological level we have shown the link exists.” Weber conducted the research with his colleagues Klaus Mathiak of RWTH Aachen University (Germany) and Ute Ritterfeld of the University of Southern California. © 2005 Michigan State University Division of University Relations

Keyword: Aggression
Link ID: 8026 - Posted: 06.24.2010

Infants born with oxygen loss who are given an innovative therapy that lowers their entire body temperature by four degrees within the first six hours of life, have a better chance of survival and lower incidence of brain injury, according to a report in the October 13 issue of the New England Journal of Medicine. "We speculate that this therapy lowers the brain temperature as well as body temperature and slows down the injury process caused by birth asphyxia, which results in loss of oxygen to the brain," said Yale researcher Richard A. Ehrenkranz, M.D., professor of pediatric neonatology and obstetrics and gynecology at Yale School of Medicine and Yale-New Haven Hospital. "Less injury means a better outcome and fewer cases of cerebral palsy and other complications." Ehrenkranz co-authored the study with colleagues at 14 other institutions in the National Institute of Child Health and Human Development Neonatal Research Network. Hypoxic ischemic encephalopathy (HIE) occurs when an infant's brain fails to receive sufficient oxygen or blood before birth. The condition may occur hours before birth or during labor and delivery. It can be caused by complications such as compression or tearing of the placenta or the umbilical cord and rupture of the uterus. Many infants who survive HIE experience brain disability.

Keyword: Development of the Brain
Link ID: 8025 - Posted: 10.13.2005

Psychological stress early in life may lead to memory loss and mental decline in middle age, research suggests. A study on rats suggests infant stress has a negative impact on the way brain cells communicate with each other. The researchers believe parental loss, abuse or neglect may contribute to a type of memory loss in middle age more normally seen in the elderly. The study, by the University of California, Irvine, features in the Journal of Neuroscience. The California team highlighted problems in the signalling mechanism between cells in an area of the brain called the hippocampus, which is known to play a key role in learning and memory. Lead researcher Dr Tallie Baram said: "The loss of cognitive function later in life is probably a result of both genetic and environmental factors. While it is not yet possible to change a person's genetic background, it may be feasible to block the environmental effects, particularly of early life stress, on learning and memory later in life. These studies point to the development of new, more effective ways to prevent cognitive impairment later in life." The researchers induced stress in rats by limiting the nesting material in cages containing females and their new-born young. The young rats appeared to overcome their initial feelings of stress but during middle age started to show signs of memory lapses. (C)BBC

Keyword: Learning & Memory; Stress
Link ID: 8024 - Posted: 10.12.2005

ANN ARBOR, Mich. -- Smokers often say that smoking a cigarette helps them concentrate and feel more alert. But years of tobacco use may have the opposite effect, dimming the speed and accuracy of a person's thinking ability and bringing down their IQ, according to a new study led by University of Michigan researchers. The association between long-term smoking and diminished mental proficiency in 172 alcoholic and non-alcoholic men was a surprising finding from a study that set out to examine alcoholism's long-term effect on the brain and thinking skills. While the researchers confirmed previous findings that alcoholism is associated with thinking problems and lower IQ, their analysis also revealed that long-term smoking is too. The effect on memory, problem-solving and IQ was most pronounced among those who had smoked for years. Among the alcoholic men, smoking was associated with diminished thinking ability even after alcohol and drug use were accounted for. The findings are the first to suggest a direct relationship between smoking and neurocognitive function among men with alcoholism. And, the results suggest that smoking is associated with diminished thinking ability even among men without alcohol problems.

Keyword: Drug Abuse; Intelligence
Link ID: 8023 - Posted: 10.12.2005

Lewis Wolpert All plants and animals, including humans, are essentially societies of cells that vary in configuration and complexity. As Darwin's theory made clear, these multitudinous forms developed as a result of small changes in offspring and natural selection of those that were better adapted to their environment. Such variation is brought about by alterations in genes that control how cells in the developing embryo behave. Thus one cannot understand evolution without understanding its fundamental relation to development of the embryo. Yet "evo devo," as evolutionary developmental biology is affectionately called, is a relatively new and growing field. Sean B. Carroll, as a leading expert both in how animals develop and in how they have evolved, is ideally placed to explain evo devo. His new book on the subject, Endless Forms Most Beautiful: The New Science of Evo Devo and the Making of the Animal Kingdom (the title borrows a phrase from Darwin's On the Origin of Species), was written, he says, with several types of readers in mind—anyone interested in natural history, those in the physical sciences who are interested in the origins of complexity, students and educators (of course), and anyone who has wondered "Where did I come from?" Carroll has brilliantly achieved what he set out to do. One of the most striking discoveries of the last half-century has been that, despite the fact that animals differ greatly in appearance, common principles control their development from a single fertilized egg. © Sigma Xi, The Scientific Research Society

Keyword: Development of the Brain; Evolution
Link ID: 8022 - Posted: 06.24.2010

The unfolding story of how a common version of a gene shapes the efficiency of the brain’s prefrontal cortex — hub of “executive” functions like reasoning, planning and impulse control — and increases risk for mental illness will be told by Daniel R. Weinberger, M.D., at this year’s G. Burroughs Mider Lecture, “Complex Genetics in the Human Brain: Lessons from COMT.” Weinberger will explain why such psychiatric genetics has proven to be a daunting challenge, using as an example the gene that codes for catecho-O-methyltransferase (COMT), the enzyme that breaks down the chemical messenger dopamine. A tiny variation in its sequence results in different versions of the gene. One leads to more efficient functioning of the prefrontal cortex, the other to less efficient prefrontal functioning and slightly increased risk for schizophrenia. New studies are revealing complex interactions between the tiny glitch and other variations within the gene, and with environmental events, such as teenage marijuana use, that may bias the brain toward psychosis. Weinberger is Director of the Genes, Cognition and Psychosis Program at the NIH’s National Institute of Mental Health. The program uses brain imaging, post-mortem analysis and molecular approaches to understand how genes work in the brain to produce schizophrenia. See: http://calendar.nih.gov/app/MCalInfoView.aspx?EvtID=11488

Keyword: ADHD; Schizophrenia
Link ID: 8021 - Posted: 06.24.2010

Eating fish at least once a week slows the toll aging takes on the brain, while obesity at midlife doubles the risk of dementia, a pair of studies concluded on Monday. Omega-3 fatty acids contained in fish have been shown to boost brain functioning as well as cutting the risk of stroke, and eating fish regularly appears to protect the brain as people age, the six-year study of Chicago residents said. "The rate of (mental) decline was reduced by 10 percent to 13 percent per year among persons who consumed one or more fish meals per week compared with those with less than weekly consumption," wrote Martha Clare Morris of Rush University Medical Center in Chicago. "The rate reduction is the equivalent of being three to four years younger in age," she added in the report published online by the Archives of Neurology. The protective effect from eating fish was evident even after researchers adjusted for consumption of fruits and vegetables. Alzheimer's disease and other causes of dementia are growing problems around the world, particularly in developed countries with aging populations. Copyright © 2005 Yahoo! Inc.

Keyword: Alzheimers
Link ID: 8020 - Posted: 06.24.2010

A potential new treatment for stroke has taken a major step forward following promising results from the first clinical trial. Researchers at The University of Manchester have shown in laboratory studies that a naturally occurring protein called IL-1ra protects brain cells from injury and death. The team, led by Professor Nancy Rothwell and Dr Pippa Tyrrell, have now reported the results of the first small trial of IL-1ra in patients, which are published in the Journal of Neurology and Neuropsychiatry. "The study was designed to test if IL-1ra is safe in stroke patients and showed promising results," said Professor Rothwell, a world-renowned neuroscientist based in the University's Faculty of Life Sciences. "The trial was a definite step in the right direction and may lead to a full trial to test its effectiveness next year." Stroke is the UK's third biggest killer and the biggest cause of disability, affecting 100,000 people each year. It accounts for 6.5% of total NHS and social services expenditure and there are currently no treatments available. Stroke occurs when vessels supplying blood to the brain become blocked and the brain is starved of oxygen. A core area of the brain dies within minutes but it is the threatened area around this core that the treatment may help to salvage.

Keyword: Stroke; Neuroimmunology
Link ID: 8019 - Posted: 10.11.2005

ATLANTA - While changing sex from female to male, the highly social bluebanded goby becomes more aggressive. At the same time, the conversion of testosterone to estrogen slows in the brain, but is unaffected in the changing gonads, according to a Center for Behavioral Neuroscience (CBN) study in the current on-line edition of Proceedings of the Royal Society B. The finding, which suggests the initial stages of sex change in fish are regulated in the brain, could help better explain the biological basis of human sexual identity. Like many fish species, the bluebanded goby switches sex in response to changes in its social environment. In a socially stable group, removal of the dominant male typically results in the dominant female changing sex to fill the void. During this process, the female experiences an array of behavioral changes and the transformation of her sex organs to male. In the study, CBN researcher and Georgia State University biology professor Matthew Grober, PhD, CBN and Georgia State post-doctoral fellow Michael Black, PhD, and researchers Jacques Balthazart, PhD, and Michelle Baillien, PhD, of the Center for Cellular and Molecular Neurobiology at the University of Liege in Belgium, attempted to determine the correlation between behavior and sex hormone conversion in four groups of gobies: a control group of females; a control group of males; dominant females who were beginning to change to males; dominant females who recently changed sex to males.

Keyword: Sexual Behavior
Link ID: 8018 - Posted: 10.11.2005

St. Paul, Minn. – Looking into our eyes may help doctors predict who is at risk for stroke. A new study found that people with changes in the small blood vessels in their eyes are more likely to later suffer a stroke than people without these signs. The results held true even after researchers took into account traditional risk factors for stroke such as smoking and high blood pressure, according to the study published in the October 11, 2005 issue of Neurology, the scientific journal of the American Academy of Neurology. The study involved 3,654 Australians age 49 and older. Researchers took special photographs of the retina of the eyes of the participants and examined them for changes suggestive of small blood vessel damage, or retinopathy. These small vessel changes can be seen in the early stages of the condition, well before eyesight is affected. “The blood vessels in the eyes share similar anatomical characteristics and other characteristics with the blood vessels in the brain,” said Paul Mitchell, MD, PhD, of the University of Sydney in Australia. “More research needs to be done to confirm these results, but it’s exciting to think that this fairly simple procedure could help us predict whether someone will be more likely to have a stroke several years later.”

Keyword: Stroke; Vision
Link ID: 8017 - Posted: 06.24.2010

A brain area presumed to be involved only in co-ordinating movement also controls higher functions, such as vision, mounting evidence suggests. Traditionally, higher mental processing has been seen as the cerebrum's job - the evolutionary newest and largest part of the brain. The cerebellum or "little brain", which sits below the cerebrum, was thought to control balance and movement. A study of brain-injured infants shows this view is too simplistic. The research in Pediatrics looked at 74 babies born prematurely who had varying degrees of brain damage. The Harvard team from the Children's Hospital in Boston used magnetic resonance imaging (MRI) brain scans to look at the injuries in detail. When there was injury to the cerebrum, the cerebellum also failed to grow to a normal size. When the cerebral injury was confined to one side, it was the opposite half of the cerebellum that failed to grow normally. Similarly, when injury occurred in one cerebellar hemisphere, the opposite side of the cerebrum was smaller than normal, which the researchers said suggested there was an important developmental link between the two parts of the brain. Other work by Dr Catherine Limperopoulos and her colleagues suggests in addition to motor problems, children born with cerebellar injuries have problems with higher cognitive processes such as communication, social behaviour and visual perception. (C)BBC

Keyword: Movement Disorders
Link ID: 8016 - Posted: 10.10.2005