Scottish researchers studied adults whose cognitive abilities were first tested in 1932, when they were 11 WASHINGTON - Age-related changes in the brain -- the appearance, starting around age 60, of "white-matter lesions" among the brain's message-carrying axons -- significantly affect cognitive function in old age. White-matter lesions are small bright patches that show up on magnetic resonance imaging (MRI) of the brain. What's more, hypertension may account for some of this cognitive impact. A full report on these relationships appears in the March issue of Psychology and Aging, which is published by the American Psychological Association (APA). Psychologists want to find the factors that contribute to individual differences in cognitive functioning among the elderly, because, says lead researcher Ian Deary, Ph.D., "People who retain their cognitive function in old age tend to have higher quality of life and live longer." However, researchers have been stymied by the lack of data on the childhood cognitive performance of elderly individuals. Without that data, it is hard to tell whether individual differences are due to aging or existed all along. Luckily, Deary, from the University of Edinburgh, and his colleagues at the University of Aberdeen, discovered that on June 1, 1932, Scotland gave its 11-year-olds a validated cognitive test. With its results, the authors gained a measure of early-life cognitive ability for people who were in their late 70s at the time of the study. © 2003 American Psychological Association

Keyword: Alzheimers
Link ID: 3600 - Posted: 06.24.2010

Milestones reached in understanding how BCL-2 family members control the apoptotic process By Ricki Lewis Apoptosis is about as complex a cellular choreography as one can imagine. Death signals impinge, chromatin cleaves, mitochondria release cell-destroying contents, and membranes undulate and form blebs, eventually shrink-wrapping the shattered cell into neat packages destined for the innards of a phagocyte. Many research groups are deciphering the cascades of proteins that orchestrate the program. Stanley Korsmeyer, a Howard Hughes Medical Institute researcher at the Dana-Farber Cancer Center in Boston, is one of them. In experiments spanning more than a decade, his group has clarified the roles of certain key proteins that regulate the mitochondrial arm of apoptosis. This issues' Hot Papers1,2 "represent milestones in the research on how BCL-2 family members control the process of cell death," says Luca Scorrano, an assistant scientist at the Dulbecco Telethon Institute at Padova University in Italy and a recent member of the Korsmeyer team. ©2003, The Scientist Inc.

Keyword: Apoptosis; Development of the Brain
Link ID: 3599 - Posted: 06.24.2010

Understanding how specific genes work could keep smokers from coveting that next hit or lighting up in the first place By Mignon Fogarty Faster than an injection, more reinforcing than crack cocaine: Smoking a cigarette speeds nicotine to the brain faster than any other delivery method, giving smokers precise control over their exact nicotine dose with each puff they take. It turns out that those two attributes--speed and control--greatly enhance nicotine's addictive effect on the brain. "It's not just the drug, but how you take it," says Timothy Baker, associate director, University of Wisconsin Center for Tobacco Research and Intervention. "Cigarette smoking introduces nicotine to the pulmonary beds of the lungs, which means it gets to the brain in seconds, without achieving general venous circulation." Nicotine mimics the neurotransmitter acetylcholine, binding to and activating a subset of receptors (the nicotinic acetylcholine receptors). Nicotine affects the brain in much the same way as cocaine, opiates, and amphetamines do; it is hard to say which drugs are more addictive. Animals can be trained to self-administer nicotine, just as they do other drugs; yet even though nicotine can be fatal, animals will not dose themselves to death, as they will with cocaine. ©2003, The Scientist Inc.

Keyword: Drug Abuse
Link ID: 3598 - Posted: 06.24.2010

Researchers have found a way to breach the body's natural defences and deliver genes and drugs into the brain. The method shows promise for treating a host of brain disorders such as Parkinson's disease. The brain is protected by a membrane formed by tight connections between the cells that line the blood vessels that supply it. This is known as the blood-brain barrier, and is designed to ensure that the brain is immune from attack from foreign substances circulating in the blood stream. Only a few molecules that are recognised by the cell receptors are allowed to pass through. However, it also means that it has proved virtually impossible to deliver genes or drugs into the brain, unless they are injected directly into its tissue. (C) BBC

Keyword: Miscellaneous
Link ID: 3597 - Posted: 03.22.2003

Trick your brain into seeing a spectrum that isn't there By Eric Haseltine In an art class I learned that black and white aren't colors in the strictest sense: They consist of a complete lack of color on the one hand and an equal combination of all colors on the other. I never found this explanation very satisfying. If black and white aren't colors, I wondered, then what precisely are they? And what about gray? Can you really get something (gray) by mixing equal amounts of nothing (black) and everything (white)? It turns out the answer is yes, but the something you get needn't be gray. It can be a bona fide color, as you'll discover by doing the following experiments. © Copyright 2003 The Walt Disney Company.

Keyword: Vision
Link ID: 3596 - Posted: 06.24.2010

By Discovery News — Chimpanzees in a remote Central African rainforest may have had little or no contact with humans until recently, said a report in the April 2003 issue of the International Journal of Primatology. The so-called naïve chimpanzees were discovered in Goualougo Triangle in the northern Democratic Republic of Congo. The 100-square-mile rainforest area is a 34-mile hike through dense forests and swampland from the nearest village. Dave Morgan, a field researcher with the Wildlife Conservation Society, and Crickette Sanz, a doctoral candidate in Anthropology at Washington University in St. Louis, described their findings in a report entitled "Naïve Encounters With Chimpanzees in the Goualougo Triangle." Copyright © 2003 Discovery Communications Inc.

Keyword: Evolution
Link ID: 3595 - Posted: 06.24.2010

Molecules behind left-right generator might help spinal cord treatments. HELEN PEARSON Thanks to a mouse that jumps like a kangaroo, researchers have discovered two molecules that drive the ability to walk. They hope that similar results might eventually help people to recover from spinal-cord injuries. Many animals' spinal cords house a circuit called the central pattern generator (CPG), which triggers legs to perform a left-right gait. Some therapies for partially paralysed patients attempt to stimulate the CPG by supporting them over a treadmill and sending electrical pulses to the spine. But exactly which nerves are involved, and how they work, has been unclear. For Klas Kullander, of Gothenburg University in Sweden, and his colleagues, the clue came from mice genetically engineered to lack two molecules called ephrinB3 and EphA4. © Nature News Service / Macmillan Magazines Ltd 2003

Keyword: Regeneration; Movement Disorders
Link ID: 3594 - Posted: 06.24.2010

In a new approach to research on minor depression, the National Institutes of Health (NIH) has launched a four-year study to determine the safety and effectiveness of St. John's wort, a common herbal supplement, and citalopram, a standard antidepressant, compared to placebo. The trial is being conducted at three sites. A total of 300 participants with minor depression will be randomly assigned a standardized extract of St. John's wort (Hypericum perforatum), citalopram, or placebo in a twelve-week double-blind trial. Researchers will assess changes in patients' symptoms, functioning, and quality of life. Those who show no improvement will receive the active treatment they hadn't been assigned before, while patients with improved symptoms will take their assigned treatment for another 14 weeks for a total of 26 weeks. The more than $4 million collaborative study is funded by the National Institute of Mental Health (NIMH), the National Center for Complementary and Alternative Medicine (NCCAM), and the Office of Dietary Supplements (ODS).

Keyword: Depression
Link ID: 3593 - Posted: 03.22.2003

Different genetic causes for obesity have been identified, raising the possibility of tailored treatments for patients. US researchers found different genes were responsible for obesity in different groups of mice. This could allow scientists to tailor different treatments for people who perhaps have a metabolic problem, and those whose bodies have flawed hunger message signals, meaning they eat too much. Scientists from US companies Rosetta Inpharmatics and Merck and the University College of Los Angeles, examined obesity in genetically altered mice. They used sophisticated techniques to discover which genes were turned on and off and which parts of the mice's genetic make-up were different. All mice were on high-fat diets, but some did not put on weight, while others did. It was found that overweight mice could be divided into two distinct genetic types. (C) BBC

Keyword: Obesity
Link ID: 3592 - Posted: 03.21.2003

An ordinary drug found in your medicine cabinet could actually help lessen the severity of, and maybe even prevent, Alzheimer’s disease. Scientists at the University of California, Los Angeles (UCLA) have discovered that common pain-killers, such as ibuprofen and naproxen, may actually help dissolve amyloid plaques, lumps of protein that form lesions in the brains of patients with this disease. What causes Alzheimer’s disease is still unknown. Dr. Gary Small, Parlow-Solomon Professor of Aging and professor of psychiatry and biobehavioral sciences at UCLA’s Neuropsychiatric Institute, describes its devastating effects: “Initially it affects your memory. Short-term memory goes first. As the disease gradually progresses, it affects all areas of cognitive function. People have personality changes. They get depressed, and they get agitated. Eventually they need total care; they can’t even feed themselves. It’s devastating to families. Care-givers themselves get depressed and overwhelmed.” All patients with Alzheimer’s disease have amyloid plaques in their brains. The plaques disrupt cell function and actually kill off brain cells, which leads to the disorientation and progressive memory loss. Dr. Jorge R. Barrio, professor of molecular and medical pharmacology at the David Geffen School of Medicine at UCLA, used a chemical marker he developed in his lab called FDDNP, which works by highlighting the amyloid plaques with a fluorescent glow. This helps him visually zero-in on the plaques. When both anti-inflammatory drugs and the chemical marker were added to diseased brain fibers, it was discovered that the drugs actually bind to the plaques. Further chemical tests indicate that the drugs may not only help dissolve existing plaques, but also prevent new ones from forming. © ScienCentral, 2000-2003.

Keyword: Alzheimers
Link ID: 3591 - Posted: 06.24.2010

By JOHN O'NEIL Some studies have indicated that people who take over-the-counter drugs like ibuprofen for several years are at lower risk for developing Alzheimer's disease. Now, a new report suggests why that may be the case. Writing in the March 31 issue of Neuroscience, researchers from the University of California at Los Angeles said it appeared that ibuprofen and other nonsteroidal anti-inflammatory drugs, including naproxen, might dissolve the brain lesions that occur in Alzheimer's. The lesions are caused by a plaque buildup. The drugs bind to the plaque, possibly preventing new lesions and dissolving existing ones, wrote the lead author, Dr. Jorge R. Barrio, and his colleagues. Copyright 2003 The New York Times Company

Keyword: Alzheimers
Link ID: 3590 - Posted: 03.21.2003

A MICROCHIP that uses chemicals instead of pulses of electricity to stimulate neurons has been created. It could open the way to implants that interact with our nervous system in a far more subtle way than is possible now. While electrical pulses convey impulses along neurons, the cells communicate with each other and with other cells such as muscles by releasing chemical messengers. These neurotransmitters are released from one side of a cell junction, or synapse, and picked up by receptors on the other side, triggering another electrical pulse. Since synapses are typically around 50 nanometres across, and each chemical puff contains just a few thousand molecules, building an artificial synapse is a huge challenge. But Mark Peterman and Harvey Fishman at Stanford University in California are getting close. They told a biophysics conference in Texas earlier this month that they have created four "artificial synapses" on a silicon chip one centimetre square.

Keyword: Robotics
Link ID: 3589 - Posted: 03.21.2003

Exclusive from New Scientist Print Edition A molecular Trojan horse that can slip past the brain's defences has proved to be very effective at delivering genes to the brains of primates. It could be used to treat a host of brain disorders, from Parkinson's to epilepsy. Treating the brain is very difficult because of the "blood-brain barrier" created by the tight junctions between the cells lining the capillaries. Only molecules recognised by the cell receptors can get in, unless they are very small. The viruses most gene therapists use to deliver genes are too big, and have to be injected directly instead. Even then, the genes are not expressed widely and evenly throughout the brain. © Copyright Reed Business Information Ltd.

Keyword: Genes & Behavior
Link ID: 3588 - Posted: 06.24.2010

ST. PAUL, MN -- Women who consume little or no caffeine, but who take hormone replacement therapy, may reduce their risk of developing Parkinson’s disease, according to a study published in the March 11 issue of Neurology, the scientific journal of the American Academy of Neurology. However, HRT may increase disease risk in women who drink the equivalent of more than five cups of coffee per day. Two large studies have previously shown that increased caffeine intake is associated with a lower risk of Parkinson’s disease in men. Studies in women, which to date have not factored in use of hormone replacement therapy, have been contradictory and inconclusive. Parkinson’s disease is less common in women, and some evidence suggests that estrogen may help protect the neurons that degenerate in this disease. Estrogen is the principal hormone in HRT, a common therapy in post-menopausal women.

Keyword: Parkinsons; Hormones & Behavior
Link ID: 3587 - Posted: 06.24.2010

By THE ASSOCIATED PRESS BOSTON, — Binge eaters who say they cannot help it may have a point. A study suggests a gene may contribute to the cause of binge eating in some people. Researchers said they hoped the finding would point the way to a pill that could bring appetites under control. The Swiss-German-American study makes the strongest case yet that a genetic mutation can cause an eating disorder, the researchers say. Researchers generally believe that eating behavior is complex and cultural in its causes. Copyright 2003 The New York Times Company

Keyword: Anorexia & Bulimia; Genes & Behavior
Link ID: 3586 - Posted: 06.24.2010

Many parasites have life cycles that involve hopping between hosts. A Toxoplasma parasite, for example, can make an infected rat unafraid of cat odors, making it easier to get to its final feline host. Now researchers think they’ve figured out how another parasite leaps from a shrimp to a bird. The sand shrimp, Gammarus insensibilis, is one host of a parasitic fluke, Microphallus papillorobustus . Normally, the crustacean tries to evade predatory birds by turning away from the sun and diving into the water, note parasitologists Frédéric Thomas of the University of Marseilles in France and Simone Helluy of Wellesley College in Massachusetts. But in parasitized shrimp, the escape reflex appears to be reversed, sending it toward the light, where birds can see it more easily. To understand how the parasite short-circuits the shrimp’s behavior, the researchers used a dye that binds to the neurotransmitter serotonin. In the 22 March issue of the Proceedings of the Royal Society of London, they report that serotonin-producing neurons in parasitized shrimp were damaged. And serotonin levels in their brains’ visual centers were 62% lower than in healthy shrimp. Thomas hypothesizes that changing serotonin levels in this part of the brain may reverse the shrimp's normal escape reflex. Copyright © 2003 by the American Association for the Advancement of Science.

Keyword: Miscellaneous
Link ID: 3585 - Posted: 06.24.2010

La Jolla, Calif.--In the developing brain, nerve cells make connections with one another by extending processes, often over long distances. The growing tips of these nerve cell processes are guided to their ultimate connection sites by molecular cues in the environment. A Salk Institute research team has discovered a receptor-protein interaction that guides nerve cells along specific pathways.

Keyword: Development of the Brain; Genes & Behavior
Link ID: 3584 - Posted: 03.20.2003

By JANE SPENCER, Staff Reporter of THE WALL STREET JOURNAL Cathy Carr, a 42-year-old Indianapolis obstetrician, is a typical American stress case. She starts her day dashing on eyeliner, nuking oatmeal for her three kids, and dishing out their attention-deficit medication. By 7:30, she is rushing around the hospital, facing circumcisions and miscarriages. Evenings are no better: "My purse isn't off my shoulder when I hear, 'What's for dinner?' she says. On top of all of it, there is a war to worry about. Her sons recently lined up toy army tanks in their bedroom in case Osama bin Laden invades the house. Dr. Carr's remedy for her mounting stress? Every few months, she checks into a hotel with her best friend and spends the weekend sopping up pink cosmopolitans and sesame-oil massages. "It's just what I need to recharge," she says. © 2003 Dow Jones & Company, Inc.

Keyword: Stress
Link ID: 3583 - Posted: 06.24.2010

By Richard Black, BBC science correspondent Doctors in Japan are developing a new way to repair damaged eyes using cells taken from the mouth. These cells are so-called stem cells which, when cultured under the right conditions in the laboratory, have the ability to grow into different types of tissue. So far, the treatment is only in the early stages of human trials. Nevertheless, it is showing a promising rate of success. The research, performed at the Kyoto Prefectural University of Medicine, has been presented at a medical meeting in Japan. Tens of thousands of people each year suffer damage, either from disease or accident, to the front part of their eyes - the cornea. This can only be repaired by grafting on new corneal tissue taken from someone else. Now doctors in Japan have come up with another approach. This involves growing a new segment of cornea using cells taken from the patient's mouth. (C) BBC

Keyword: Vision; Stem Cells
Link ID: 3582 - Posted: 03.19.2003

Drugs to protect against a nerve-gas attack are a distant goal A possible "achilles heel" for chemical weapons has been found. Scientists have discovered how organophosphate chemicals act on nerves, raising new possibilities for developing antidotes. The research adds weight to the argument that genetics may play a role in human susceptibility to organophosphates. The class of chemicals includes household pesticides as well as deadly nerve gases like sarin. Experiments in mice show organophosphate nerve agents target a key enzyme. Genetically-altered rodents with low levels of the enzyme were more sensitive to the chemical. The mice were more likely to die or show symptoms such as hyperactivity when exposed to high doses of organophosphates. (C) BBC

Keyword: Neurotoxins
Link ID: 3581 - Posted: 03.19.2003