Electrodes placed deep in the brains of severely depressed patients alleviate their misery when no other treatments can, according to new research. Deep brain stimulation is a relatively new approach to treating brain disease. Unlike electroconvulsive or "shock" therapy, which involves placing electrodes on the scalp, deep brain stimulation delivers small jolts of electricity directly to specific parts of the brain. The technique has been used with some success to alleviate the symptoms of Parkinson’s disease, but no one had tried it for depression. Researchers led by Helen Mayberg of the Emory University School of Medicine in Atlanta, Georgia, targeted the subgenual cingulate, a part of the emotional brain that has been shown to be hyperactive in depression. The team implanted electrodes in the brains of six patients, all of whom had failed to benefit from a variety of therapies, including shock treatments. The electrodes were attached to generators implanted under their collarbones that continuously delivered high-frequency, low-voltage pulses of electricity. All patients experienced immediate effects from the stimulation--reporting such impressions as a "disappearance of the void" and feelings of "connectedness." After 6 months with the implants, four of the six said their depression had mostly lifted. In one woman, the experimenters tried turning off the stimulator and found that depressive symptoms gradually returned after a few weeks. But she cheered up soon after the current was turned on again, the scientists report today in Neuron. Mayberg believes that the longer the treatment period, the more durable the effects will be. --CONSTANCE HOLDEN Copyright © 2005 by the American Association for the Advancement of Science.

Keyword: Depression
Link ID: 6969 - Posted: 06.24.2010

Certain genetic diseases affect children's educational abilities in a distinctive pattern: impairing their numerical abilities more than their verbal skills. New research sheds light on this split in abilities by investigating how differences in brain structures may influence how the mind works. Researchers at The Children's Hospital of Philadelphia, studying a common chromosome disorder, have used high-tech imaging tools to identify abnormal brain tissue associated with problems in perceiving spatial relationships and thinking about numbers. Understanding the links between brain structure and brain function may offer clues to improving methods to help children with specific learning disabilities. By pinpointing specific sites in the brain associated with impaired mental functions, scientists hope to eventually help children retrain their brains to follow alternative pathways and work around their cognitive weaknesses. Cognitive neuroscientist Tony J. Simon, Ph.D., led the studies of children with chromosome 22q11.2 deletion syndrome, the most common genetic deletion syndrome. In this disorder, a tiny portion of chromosome 22 is missing, causing symptoms such as heart defects, cleft palate, abnormal immune responses and cognitive impairments. Children's Hospital is a world center for research and treatment of the syndrome.

Keyword: Intelligence; Development of the Brain
Link ID: 6968 - Posted: 03.04.2005

Rex Dalton A computer-generated model of the skull of Homo floresiensis, our diminutive human relative, confirms that the controversial specimens from Indonesia do indeed represent a new species. The study of the creature's brainpan shows that it was neither a pygmy nor an individual with a malformed skull and brain, as some critics contend. This lends support to the discovery team's assertion that the metre-tall specimen belongs to a species distinct from Homo erectus. A skull and bones from eight H. floresiensis individuals were unearthed in a cave on Indonesia's island of Flores over 2003 and 2004 by a team of Indonesian and Australian researchers. The new species, which may have been alive as recently as 18,000 years ago, was reported in Nature1,2 last October. It generated huge fanfare among scientists and anthropology buffs. But a handful of critics have questioned the scientific description, contending that the specimens represent a tribe of pygmies, with at least one member having a deformed skull and brain, a condition called microcephaly. ©2005 Nature Publishing Group

Keyword: Evolution
Link ID: 6967 - Posted: 06.24.2010

By Patrik Jonsson | Correspondent of The Christian Science Monitor RALEIGH, N.C. – Hardly articulate, the tiny strangleweed, a pale parasitic plant, can sense the presence of friends, foes, and food, and make adroit decisions on how to approach them. Mustard weed, a common plant with a six-week life cycle, can't find its way in the world if its root-tip statolith - a starchy "brain" that communicates with the rest of the plant - is cut off. The ground-hugging mayapple plans its growth two years into the future, based on computations of weather patterns. And many who visit the redwoods of the Northwest come away awed by the trees' survival for millenniums - a journey that, for some trees, precedes the Parthenon. As trowel-wielding scientists dig up a trove of new findings, even those skeptical of the evolving paradigm of "plant intelligence" acknowledge that, down to the simplest magnolia or fern, flora have the smarts of the forest. Some scientists say they carefully consider their environment, speculate on the future, conquer territory and enemies, and are often capable of forethought - revelations that could affect everyone from gardeners to philosophers. Indeed, extraordinary new findings on how plants investigate and respond to their environments are part of a sprouting debate over the nature of intelligence itself. Copyright © 2005 The Christian Science Monitor.

Keyword: Intelligence; Evolution
Link ID: 6966 - Posted: 06.24.2010

The first experimental evidence that birds can be deceived by camouflage in the same way that humans are deceived, is published today in Nature The first experimental evidence that birds can be deceived by camouflage in the same way that humans are deceived, is published today in Nature [3 March 2005]. The idea that bold contrasting colours help to break-up the body's outline was rapidly adopted by many armies as long ago as the First World War. And in biology this idea of 'disruptive colouration' has long been used to explain how insects such as moths conceal themselves from predators, shaping the evolution of protective coloration in insects. Innovative research from the University of Bristol provides the strongest evidence to date that disruptive patterns do indeed protect insects from detection by birds, the predator most likely to have shaped the evolution of protective coloration in insects. Professor Innes Cuthill and his team pinned artificial 'moths' to trees in a field with a dead mealworm attached. The 'moths' were triangular pieces of waterproof card with specific patterns printed on them. By varying the colours, size and location of patterns on the moths the team were able to mimic real tree characteristics and identify which pattern combinations were the most successful.

Keyword: Vision
Link ID: 6965 - Posted: 03.03.2005

MINNEAPOLIS / ST. PAUL--Mistakes made by human subjects in identifying the facing direction of faces, cars or meaningless objects have yielded evidence that the brain contains nerve cells, or neurons, whose job is to encode the viewing angle of objects. It is well known that certain neurons respond to color, motion, edges and other aspects of our environment. Now, University of Minnesota researchers have found that our visual cortex contains neurons that tell us, for example, whether a face is turned in our direction or not. The work adds to knowledge of how the brain collects and processes visual information leading to the recognition of objects, and it may inform the design of machine vision. The study will be published in the March 3 issue of the journal Neuron. The brain relies on millions of neurons to report the visual elements of our environment. But, for example, if every neuron geared to motion fired in response to any motion whatsoever, then we couldn't tell whether a train was chugging into the distance or bearing down on us. Instead, to gain a complete picture of the world, our brains appear to contain separate, but physically intertwined, populations of neurons that respond to only one small aspect of our environment. The brain then bases its interpretation of images largely on which neurons fire. "The issue is, what is the underlying neural mechanism that supports the ability to recognize objects viewed from different angles?" said Sheng He, associate professor of psychology, who directed the study. "This study supports the idea that we have explicit representations in our brains for specific views of objects." The study was carried out jointly with Fang Fang, a graduate student in He's laboratory.

Keyword: Vision
Link ID: 6964 - Posted: 03.03.2005

JOHN HALPERN clearly remembers what made him change his mind about psychedelic drugs. It was the early 1990s and the young medical student at a hospital in Brooklyn, New York, was getting frustrated that he could not do more to help the alcoholics and addicts in his care. He sounded off to an older psychiatrist, who mentioned that LSD and related drugs had once been considered promising treatments for addiction. "I was so fascinated that I did all this research," Halpern recalls. "I was reading all these papers from the 60s and going, whoa, wait a minute! How come nobody's talking about this?" More than a decade later, Halpern is now an associate director of substance abuse research at Harvard University's McLean Hospital and is at the forefront of a revival of research into psychedelic medicine. He recently received approval from the US Food and Drug Administration (FDA) to give late-stage cancer patients the psychedelic drug MDMA, also known as ecstasy. He is also laying the groundwork for testing LSD as a treatment for dreaded super-migraines known as cluster headaches. And Halpern is not alone. Clinical trials of psychedelic drugs are planned or under way at numerous centres around the world for conditions ranging from anxiety to alcoholism. It may not be long before doctors are legally prescribing hallucinogens for the first time in decades. "There are medicines here that have been overlooked, that are fundamentally valuable," says Halpern. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse
Link ID: 6963 - Posted: 06.24.2010

Long distance messengers star in many heroic tales, perhaps the most famous being the one about the runner who carried the news about the victory of the Greeks over the Persians in the fateful battle of Marathon. A team of researchers at the Weizmann Institute of Science has now discovered how molecular messengers perform a crucial role in the ability of injured nerve cells to heal themselves. A nerve cell has a cell body and a long extension, called an axon, which in humans can reach up to one meter in length. Nerve cells belonging to the peripheral nervous system can regrow when their axons are damaged. But how does the damaged axon inform the cell body that it must start producing vital proteins for the healing? That's precisely where the molecular messengers, proteins called Erk-1 and Erk-2, enter the picture. When the axon is injured, these proteins bind to molecules of phosphorus. In this phosphorylated state, they can communicate to command centers in the cell, transmitting a message that activates certain genes in the cell body, which then manufactures proteins that are vital for the healing of the injured axon. The problem is that the messengers must transmit their phosphorus message over a great distance along the axon, and in the course of this arduous journey can easily lose their phosphorus en route.

Keyword: Regeneration
Link ID: 6962 - Posted: 03.03.2005

The first evidence for a possible treatment for Fragile X syndrome, one of the leading inherited causes of mental retardation, has emerged from experiments with a mutant fruit fly that exhibits characteristics of the disorder. The disorder affects one in 6000 births and also causes accompanying sleep disorders, attention deficit disorder, hyperactivity, aggression, and autistic behavior. Researchers Sean M.J. McBride from Albert Einstein College of Medicine, Thomas A. Jongens from University of Pennsylvania School of Medicine, and their colleagues studied a mutant strain of the fruit fly Drosophila that lacks the fly version of the same gene that is mutated in humans with Fragile X syndrome. The gene, FMRP, codes for a protein that binds specific messenger RNAs--carriers of genetic information in the cell--and enables them to function properly. The mutant flies lack the ability of normal flies to adjust courtship behavior that is dependent on learning and memory. In such conditioned courtship, a male fly learns to modify his courtship behavior--including following the female, vibrating a wing, tapping the female, and attempting to copulate--according to the response of the female. Studies of a mouse lacking the Fragile X gene had revealed that it showed increased activity of the metabotropic glutamate receptor (mGluR) on the surface of neurons.

Keyword: Genes & Behavior; Development of the Brain
Link ID: 6961 - Posted: 03.03.2005

Clearance of beta amyloid accumulation within neurons stops memory decline in mice Researchers at UC Irvine have identified a trigger at the molecular level that marks the onset of memory decline in mice genetically engineered to develop brain lesions – in the form of plaques and tangles – associated with Alzheimer's disease. The trigger is a protein called "beta amyloid" that accumulates within neurons in the mice's brains. Although several researchers have studied the association between beta amyloid and memory, the UCI research team is the first to identify that early beta amyloid accumulation within neurons is the trigger for the onset of memory decline in Alzheimer's. "This finding has important and useful implications for the pharmaceutical industry in terms of developing drugs that can target beta amyloid as soon as it accumulates within the neurons," said Frank LaFerla, principal investigator of the research project, associate professor of neurobiology and behavior, and co-director of the UCI Institute for Brain Aging and Dementia. "Once the plaques and tangles form, it is too late." The researchers report their findings in the March 3 issue of Neuron.

Keyword: Alzheimers
Link ID: 6960 - Posted: 06.24.2010

Dr. Peter Hurd initially thought the idea was "a pile of hooey", but he changed his mind when he saw the data. Hurd and his graduate student Allison Bailey have shown that a man's index finger length relative to ring finger length can predict how inclined that man is to be physically aggressive. Women do not show a similar effect. A psychologist at the University of Alberta, Hurd said that it has been known for more than a century that the length of the index finger relative to the ring finger differs between men and women. More recently, researchers have found a direct correlation between finger lengths and the amount of testosterone that a fetus is exposed to in the womb. The shorter the index finger relative to the ring finger, the higher the amount of prenatal testosterone, and--as Hurd and Bailey have now shown--the more likely he will be physically aggressive throughout his life. "More than anything, I think the findings reinforce and underline that a large part of our personalities and our traits are determined while we're still in the womb," said Hurd. Hurd and Bailey's research, published this March in Biological Psychology, was determined from surveys and hand measurements of 300 U of A undergraduates.

Keyword: Aggression; Hormones & Behavior
Link ID: 6959 - Posted: 03.03.2005

Parents need have no more fears about the triple vaccine against measles, mumps and rubella. A study of more than 30,000 children in Japan should put the final nail in the coffin of the claim that the MMR vaccine is responsible for the apparent rise in autism in recent years. The study shows that in the city of Yokohama the number of children with autism continued to rise after the MMR vaccine was replaced with single vaccines. "The findings are resoundingly negative," says Hideo Honda of the Yokohama Rehabilitation Center. In the UK, parents panicked and vaccination rates plummeted after gastroenterologist Andrew Wakefield claimed in a 1998 study that MMR might trigger autism, although the study was based on just 12 children and later retracted by most of its co authors. Soon the vaccine was being blamed for the apparent rise in autism, with Wakefield citing data from California, US (see graph). In some parts of the UK, the proportion of children receiving both doses of the MMR vaccine has dropped to 60%. This has led to a rise in measles outbreaks and fears of an epidemic. © Copyright Reed Business Information Ltd.

Keyword: Autism
Link ID: 6958 - Posted: 06.24.2010

Ruth Francis A recorder player has fascinated neuroscientists with her ability to taste differences in the intervals between notes. The condition in which the brain links two or more of the senses is known as synaesthesia, and some sense combinations are relatively common. But this is the first time that the ability has been found to help in performing a mental task, such as identifying a major third. Elizabeth Sulston was at school when she first noticed that she saw colours while hearing music. She realized that the same was not true of her peers, although linkage of tone and colour is a known synaesthetic combination. As she began to learn music more formally, she found that when hearing particular tone intervals she experienced a characteristic taste on her tongue. For example, a minor third tasted salty to her, whereas a minor sixth tasted like cream. She started to use the tastes to help her recognize different chords. Talking to news@nature.com, she says: "I always had the synaesthesia, but really became conscious of it at 16. Then I started to use it for the tone-interval identification. I could first check it by counting the space between the notes, and second by 'feeling' my tongue." ©2005 Nature Publishing Group

Keyword: Hearing
Link ID: 6957 - Posted: 06.24.2010

Passive smoking kills more than 11,000 a year in the UK - much higher than previously thought, a study shows. The British Medical Journal study also gives a figure for people dying from second-hand smoke in the workplace - 600 a year - for the first time. Leading doctors said the findings proved a complete ban on smoking in public places was needed. But smoking lobby group Forest said there was still little hard evidence of the effect of passive smoking. November's Public Health White Paper proposed a ban on smoking in public places with the exception of pubs which do not serve food. At the time much of the medical establishment criticised the proposals for not going far enough. But doctors have thrown their support behind Liverpool's bid to introduce a complete ban in all workplaces, which is due before the House of Lords later this month. Researchers at University of Queensland in Australia compiled the report from UK databases of causes of death, employment, structure of households and levels of active smoking and exposure to passive smoking. They found 2,700 deaths among people aged 20 to 64 could be attributed to second-hand smoke and 8,000 in 65-year-olds and over. A further 617 deaths were caused by workplace passive smoking, including 54 in the hospitality industry. Report author Konrad Jamrozik said: "It is clear that adoption of smoke free policies in all workplaces in the UK might prevent several hundred premature deaths each year." Previous studies have put the figure much lower. The British Medical Association estimated it was 1,000 a year three years ago but said the latest study was a much more comprehensive guide to the problem. (C)BBC

Keyword: Drug Abuse
Link ID: 6956 - Posted: 03.02.2005

Shares in Elan and Biogen Idec plunged on Monday as the firms suspended sales of new multiple sclerosis drug Tysabri after a patient's death in the US. On the New York Stock Exchange, shares in Ireland-based Elan lost 70% while US partner Biogen Idec shed 43%. The firms took action after the death from a central nervous system disease and a suspected case of the condition. The cases cited involved the use of both Tysabri and Avonex, Biogen Idec's existing multiple sclerosis drug. The companies said they have no reports of the rare condition - progressive multifocal leukoencephalopathy (PML) - in patients taking either Tysabri or Avonex alone. Tysabri was approved for use in the US last November and was widely tipped to become the world's leading multiple sclerosis treatment. "The companies will work with clinical investigators to evaluate Tysabri-treated patients and will consult with leading experts to better understand the possible risk of PML," the two firms said in a statement. "The outcome of these evaluations will be used to determine possible re-initiation of dosing in clinical trials and future commercial availability." The decision to suspend sales of the drug was welcomed by Christine Jones, chief executive of the UK MS Trust. She said: "Clearly, it is vital to protect the interests and safety of patients at all times and we are pleased that such prompt action has been taken. (C)BBC

Keyword: Multiple Sclerosis
Link ID: 6955 - Posted: 03.02.2005

(Embargoed) CHAPEL HILL -- Scientists at the University of North Carolina at Chapel Hill may have identified the genetic basis underlying essential tremor disease, the most common human movement disorder. The discovery comes from studies involving a strain of genetically altered mice that show the same types of tremor and similar lack of coordination as people affected by essential tremor. This animal model of the disease might prove useful for screening potential treatments, said Dr. A. Leslie Morrow, associate director of UNC's Bowles Center for Alcohol Studies and professor of psychiatry and pharmacology in UNC's School of Medicine. "We believe that these mice could explain one etiology, or origin, of essential tremor disease in humans because of the marked similarities between the mouse model and the human disease," said Morrow, who led the study team. A report of the findings will appear in the March issue of the Journal of Clinical Investigation. An estimated 5 million Americans are affected by essential tremor, a neurological disease characterized by an uncontrollable shaking of the limbs, in particular the arms and head. Unlike resting tremor associated with Parkinson's disease, symptoms of essential tremor are noticeable during movement, such as lifting a cup of coffee.

Keyword: Movement Disorders
Link ID: 6954 - Posted: 03.02.2005

Posted by Carl Zimmer Earlier this month I wrote two posts about the evolution of the eye, a classic example of complexity in nature. (Parts one and two.) I'd like to write now about another case study in complexity that has fascinated me for some time now, and one that has sparked a fascinating debate that has been playing out for over fifteen years. The subject is language, and how it evolved. In 1990, Steven Pinker (now at Harvard) and Paul Bloom (now at Yale) published a paper called "Natural Selection and Natural Language." They laid out a powerful argument for language as being an adaptation produced by natural selection. In the 1980s some pretty prominent scientists, such as Stephen Jay Gould, had claimed that the opposite was the case--namely, that language was merely a side effect of other evolutionary forces, such as an increase in brain size. Pinker and Bloom argued that the features of language show that Gould must be wrong. Instead, they maintained, language shows all the classic hallmarks of an adaptation produced by natural selection. Despite the superficial diversity of languages, they all share a basic underlying structure, which had first been identified by Noam Chomsky of MIT in the 1960s. Babies have no trouble developing this structure, which you'd expect if it was an in-born capacity rather than a cultural artefact. Copyright © 2004 Corante.

Keyword: Language; Evolution
Link ID: 6953 - Posted: 06.24.2010

RICHMOND, Va. – Virginia Commonwealth University researchers have identified several genetic changes in the brains of mice caused by ethanol, which may help researchers better understand how and why people become addicted to alcohol. In the March issue of the Journal of Neuroscience, researchers reported significant differences in the gene expression patterns regulated by alcohol in two mouse strains known as B6 and D2. The two mouse strains differ in a number of behavioral responses to acute alcohol and in their predisposition to drink alcohol. Researchers isolated tissue from three different regions of the brain that are all known to play a role in responses to alcohol and other drugs of abuse. Using DNA microarrays, which measure the activity of more than 10,000 genes simultaneously, together with large databases of other biological information, researchers were able to identify several genes regulated by alcohol that may play a role in determining genetic differences in behavioral responses to alcohol. "These findings help us to better understand the molecular basis for genetic differences in behavioral response to alcohol and may eventually lead to new therapeutic approaches for alcoholism," said Michael Miles, M.D., Ph.D., a professor in pharmacology, toxicology and neurology, who also has an appointment in VCU Life Sciences' Center for the Study of Biological Complexity.

Keyword: Drug Abuse
Link ID: 6952 - Posted: 06.24.2010

New Haven, Conn.--A family of proteins that help build the cytoskeleton, or the bones of the cell, also play an important role in learning and memory, according to a study published this month in The Journal of Neuroscience. Marina Picciotto, associate professor of psychiatry, pharmacology and neurobiology at Yale School of Medicine, and the senior author of the study, studied mice missing one of these proteins--â-adducin--and found the cytoskeleton developed normally. However, the mice were impaired during fear conditioning and memory exercises. "We were hoping to find a mechanism that cells use to make short term changes in nerve cell communication permanent, but we were surprised that losing â-adducin made such a big change in both the nerve cell communication and in behavioral measures of memory," Picciotto said. The focus of the study is long-term potentiation, which is a form of neuronal plasticity and may form the biological basis for some kinds of memory. Long-term potentiation refers to the fact that if two neurons in the hippocampus are active at the same time, the connection between them can be strengthened. This change, or potentiation, can last for hours to days. This may serve to lay a foundation for more permanent changes, such as the construction of new connections, or synapses, between the neurons.

Keyword: Learning & Memory
Link ID: 6951 - Posted: 03.02.2005

Roxanne Khamsi When snakes evolved venom, they co-opted proteins from all over their bodies, says an analysis of 24 different toxins. Surprisingly, very tiny tweaks were enough to transform harmless proteins into deadly poison, and this may help drug designers to create proteins with precise biological effects. Venomous snakes developed glands for the storage and dispersal of their saliva about 60-70 million years ago. Since then, various species have built up an arsenal of toxins to attack their victims. Different venoms attack different types of cell in the body, for example muscle cells or blood cells. This dramatic specificity has led scientists to speculate that the venoms originate from proteins produced in different organs throughout the body, which already interact with these cell types. But champions of this theory lacked hard evidence from more than a few toxins. Despite the incredible changes in bioactivity that occur, the proteins' basic shapes don't change notably. ©2005 Nature Publishing Group

Keyword: Neurotoxins
Link ID: 6950 - Posted: 06.24.2010