THE secret of an African herb that helps drug addicts and alcoholics kick the habit has been discovered. The finding could lead to safer and more effective medications for treating addiction. Since the 1960s, many addicts have reported that even a single dose of ibogaine, a hallucinogenic alkaloid extracted from the root of an African shrub, helps them kick their habit by reducing their cravings for drugs. And there is hard evidence to back these claims, as well. However, troubling side effects - including heart problems and several deaths - have kept ibogaine from being widely accepted as a medical treatment. Instead, a few researchers have begun searching for ways to deliver ibogaine's benefits without its risks (New Scientist, 26 April 2003, p 34). A few previous studies have suggested that becoming addicted to a substance lowers the production of a nerve growth factor called glial cell-line derived neurotrophic factor, or GDNF. So Dorit Ron's team at the University of California, San Francisco, decided to test whether ibogaine affects GDNF levels in the brain. In rats injected with ibogaine, the researchers found that production of GDNF increased in a region of the brain called the ventral tegmental area. What's more, injecting either ibogaine or GDNF itself directly into this brain area decreased alcohol cravings in addicted rats, whereas injecting anti-GDNF antibodies eliminated any beneficial effect of ibogaine. The results appear in The Journal of Neuroscience. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse
Link ID: 6767 - Posted: 06.24.2010

Blasts of bitter cold air to the face, mountains of snow and sneaky black ice put few people in a sunny mood. But surprisingly, the weather has little affect on people's overall state of mind, according to research that will be published in an upcoming issue of the journal Psychological Science. Three years ago, Matthew Keller, the lead author of the article, found himself in the doldrums of a Michigan winter. He was completing his graduate degree in psychology and spending most of his time working indoors. Any time he was able to escape, Old Man Winter offered a chilling embrace. Finally Keller chased away his winter blues with a trip to Mexico. "When I left Michigan to go to Mexico, I just felt like there was color in life again," he says. When Keller returned that spring, he decided to test how the weather really affects people's mood and cognitive ability. He and his colleagues conducted three separate studies evaluating people's moods, memories and openness to new information. In the first of the three studies, nearly 100 volunteers filled out questionnaires reporting their general mood, the amount of time they spent outside that day, and their general activity level. The study's participants were also asked to perform two cognitive tests. The first tested volunteers' ability to listen to a string of numbers and accurately repeat them, while the second evaluated their willingness to change pre-established opinions after receiving new information regarding an issue or person. In all cases, higher scores indicated better moods and cognitive ability. Keller correlated this survey information with local weather data collected from the National Climatic Data Center. © ScienCentral, 2000- 2005.

Keyword: Depression; Biological Rhythms
Link ID: 6766 - Posted: 06.24.2010

Scientists have discovered how to make cells sensitive to light in what may lead to a new approach to treating certain forms of blindness. The research, published today (January 27) in the science journal Nature, shows that a gene called melanopsin causes nerve cells to become photoreceptive. The team of experts from The University of Manchester and Imperial College London found that activating melanopsin in cells that don't normally use the gene makes them sensitive to light. "The melanopsin made the cells photoreceptive which tells us that this protein is able to absorb light," said Dr Rob Lucas, who led the team in Manchester. "This discovery might provide food for thought for scientists looking for ways of treating visual loss." Dr Lucas, whose research concerns the effect light has on our daily rhythms, said the classical view of how the eye sees is through photoreceptive cells in the retina called rods and cones. But Dr Lucas and Professor Hankins were part of a team that recently discovered a third type of photoreceptor, although the mechanisms of how it worked had not been fully understood – until now. "Over the last few years it has become increasingly accepted that we have a third system that uses melanopsin and has lain undetected during years of vigorous scientific investigation," said Dr Lucas.

Keyword: Vision; Biological Rhythms
Link ID: 6765 - Posted: 06.24.2010

A mystery chemical that young women deploy as a sex attractant pheromone seems to work for post-menopausal women too. Joan Friebely of Harvard University, US, and Susan Rako, a private physician in Newton, Massachusetts, US, have studied 44 post-menopausal women. Half added Athena Pheromone 10:13, originally isolated from a woman's armpit sweat, to their perfume while half added a dummy compound. Neither the women nor the researchers knew who was in each group until the results were in. In diaries kept by the women for six weeks, 41% of pheromone users reported more petting, kissing and affection with partners compared with 14% receiving the placebo. Overall, 68% of pheromone users reported increases in at least one of four "intimate socio-sexual behaviours" such as formal dates and sex, as against 41% on the placebo. But the pheromone's discoverer, biologist Winnifred Cutler, is keeping its identity secret until patents have been granted to Cutler's Athena Institute for Women's Wellness Research in Chester Springs, Pennsylvania, US. "It's still a mystery substance being applied to individuals at unknown concentrations," says George Preti of the Monell Chemical Senses Centre in Philadelphia, Pennsylvania. Friebely and Rako say they have no financial interest in the product. Journal reference: The Journal of Sex Research (vol 41, p 372) © Copyright Reed Business Information Ltd.

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 6764 - Posted: 06.24.2010

BLOOMINGTON, Ind. -- Meeting a friend you haven't seen in years brings on a sudden surge of pleasant memories. You might even call it an avalanche. Recent studies suggest that avalanches in your brain could actually help you to store memories. Last year, scientists at the National Institutes of Health placed slices of rat brain tissue on a microelectrode array and found that the brain cells activated each other in cascades called "neuronal avalanches." New computer models now suggest that these brain avalanches may be optimal for information storage. If so, certain neurochemical treatments might someday improve life for people with memory problems. A report of this work will be published Feb. 4 in the journal Physical Review Letters. "When most people think of an avalanche, they imagine something huge," said biophysicist John Beggs, now a professor in the Biocomplexity Institute at Indiana University Bloomington, who helped perform the NIH experiments. "But avalanches come in all sizes, and the smaller ones are most common. That's just what we found in the brain cells." Copyright 2004, The Trustees of Indiana University

Keyword: Learning & Memory
Link ID: 6763 - Posted: 01.27.2005

By ANDREA LU How the nose knows remains one of the biggest puzzles in science. In an effort to better understand our olfaction, or smell, system, a team of UC Berkeley scientists led by psychology professor Noam Sobel discovered a mechanism in the brain that controls odor detection. “We live in a world in which we’re constantly surrounded by odors. We were trying to find out how it is that we’re not constantly overwhelmed by these odors around us, or how it is that we can tune then out and focus on other things,” said Christina Zelano, biophysics graduate student and lead author of the study. In the study published in December on Nature Neuroscience online, the scientists reported that a region in the primary olfactory cortex of the brain stops an individual from noticing surrounding scents unless the level of odor is high or the person is intentionally trying to smell something. “We ended up identifying a novel brain mechanism that functions as a gate, allowing our brain to focus on what our nose is telling us when we want it to, and more importantly, to tune it out when we’re working on other things,” Zelano said. Zelano says the paper is the first to demonstrate attention in olfaction. “In our study, we found that a frontal sub-region of primary olfactory cortex became more active when subjects were preparing for an olfactory task compared to when they were preparing for an auditory task. This is a very strong demonstration of the fact that sensory processing is an active, rather than a passive process—mammals have evolved to actively seek out the stimuli around them rather than to sit still and have stimuli thrown at them,” Zelano said.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 6762 - Posted: 06.24.2010

By Jennifer Warner -- Despite the famous link between ALS and baseball great Lou Gehrig, a new study shows that there's no medical link between the disease and physical activity. Researchers found no association between increased physical activity and the risk of developing ALS (amyotrophic lateral sclerosis). Those results contradict several previous studies that have shown that slim, athletic individuals may be more likely to develop ALS. ALS is also sometimes called "Lou Gehrig's disease," after the famous baseball player whose career was cut short by the disease, which gradually erodes muscle strength. Although ALS is often very disabling, many people live for years with the disease. The average life expectancy is only two to five years. In the study, researchers compared the amount of physical activity reported by 219 people with ALS with 254 healthy people. All of the participants were asked whether they engaged in sports as youngsters or as an adult or whether they performed extreme physical activity. They reported total physical activity levels as well as activity levels in three different phases of their lives: before age 25, the last 10 years before symptoms of the disease emerged, and one year before the start of the disease. ©1996-2005 WebMD Inc.

Keyword: ALS-Lou Gehrig's Disease
Link ID: 6761 - Posted: 06.24.2010

By WILLIAM GRIMES In the summer of 1849, Walt Whitman walked into an office on Nassau Street in Manhattan to have his head read. Lorenzo Niles Fowler, a phrenologist, palpated 35 areas on both sides of the skull corresponding to emotional or intellectual capacities in the brain. Fowler rated each one on a scale of 1 to 7, with 6 representing the ideal (7 meant dangerous excess). Whitman received a perfect score in nearly every one of Fowler's categories, which bore such fanciful names as "amativeness," "adhesiveness" and "combativeness." Thrilled with his report card, he became an instant convert to phrenology, defined by Ambrose Bierce as "the science of picking a man's pocket through the scalp." Later he donated his magnificent brain to the American Anthropometric Society, which collected it on his death in 1892 and added it to its collection of elite brains. There are quite a few such collections, scattered around the globe, and Brian Burrell visits all of them in his offbeat scientific tour in "Postcards From the Brain Museum." His wanderings take him from the Musée de l'Homme in Paris and the Wistar Institute of Anatomy and Biology in Philadelphia to the impressively stocked Institute of the Brain in Moscow, where the brains of Lenin, Stalin, Eisenstein and Pavlov lie in state, or states, having been sliced into thousands of paper-thin slices and stained for scientific study. Copyright 2005 The New York Times Company

Keyword: Miscellaneous
Link ID: 6760 - Posted: 01.26.2005

By JAN HOFFMAN When Janet Golden was kicking around in utero 53 years ago, pregnant women of her mother's generation were encouraged to enjoy their 5 o'clock cocktails. A martini calmed nerves; a glass of wine helped a woman to sleep. But don't drink too much, obstetricians cautioned: all those empty calories! By the mid-1960's, many obstetricians even believed that alcohol could halt premature labor. As noted by Dr. Golden, now a medical historian at Rutgers University in Camden, N.J., when women arrived at the hospital in premature labor, they were often handed a vodka and orange juice or given alcohol intravenously. But in 1973, a new diagnosis, fetal alcohol syndrome, had been identified in the children of women who drank heavily during pregnancy. The symptoms included diminished I.Q., small stature, flat face and drooping eyelids. In her new book, "Message in a Bottle: The Making of Fetal Alcohol Syndrome" (Harvard University Press), Dr. Golden argues that the political, legal, medical and social response to fetal alcohol syndrome has been inconsistent, often illogical and frequently volatile. If alcoholism has been acknowledged as a disease, she observes, then why have pregnant women who drink been charged with child abuse? Copyright 2005 The New York Times Company

Keyword: Drug Abuse; Development of the Brain
Link ID: 6759 - Posted: 01.26.2005

Scientists say they have found the brain regions that help us to decide whether to look someone in the eye or look away. Using brain imaging, the Imperial College London team pinpointed specific areas deep within the frontal cortex. One region works when we decide to look at something, while another works if we change our mind at the last minute. It might help doctors better understand certain brain diseases, they told the journal, Current Biology. Where we choose to look is fundamental to how we interact with other people. On some occasions we might want to look someone straight in the eye, but at other times we might decide to avert our gaze and look away. It has been thought that the frontal lobe is involved in helping a person select between conflicting voluntary actions such as this. It is also known that people who have damage to their frontal lobe have difficulties in spontaneously initiating voluntary actions. To investigate further, Dr Masud Husain and colleagues asked volunteers to perform a visual task while undergoing a brain scan. The volunteers were shown an image and asked to either choose which part they looked at and fixate on that, or change their minds and look elsewhere. (C)BBC

Keyword: Vision
Link ID: 6758 - Posted: 01.26.2005

A study by New York University researchers reveals a new function for the nerve cells that regulate circadian rhythms of behavior in fruit flies. The nerve cells, called pacemaker neurons, contain a molecular clock that controls a 24-hour circadian rhythm in activity similar to the rhythms in sleep/wake cycles found in humans and many other organisms. It was previously known that pacemaker neurons receive visual signals to reset their molecular clocks, but scientists did not have any evidence that they transmitted information to their target cells, as most other neurons do. The current study shows that pacemaker neurons do in fact transmit signals and are required for a rapid behavior, according to the paper, published in the January 20th issue of Neuron. The study was conducted by Esteban O. Mazzoni, a graduate student in NYU's Biology Department, Biology Professor Claude Desplan, and Assistant Biology Professor Justin Blau. The finding suggests it may be possible to identify genes that can be used to treat problems such as sleep disorders and jet lag. The researchers examined the role that pacemaker neurons play in helping Drosophila larvae avoid light. Drosophila is a species of fruit fly commonly used in biological research. Fruit fly larvae foraging for food avoid light, presumably to keep away from predators. Unlike adult Drosophila, the larvae only have one structure for gathering visual cues, called Bolwig's Organ. This organ senses the amount of light in the environment and transmits that information to the pacemaker neurons to reset their molecular clocks.

Keyword: Biological Rhythms
Link ID: 6757 - Posted: 01.26.2005

There’s a reason why we listen to music on the FM dial of our radios – it just sounds better than it does on AM. And this reason also holds true for cochlear implants and hearing aids. UC Irvine School of Medicine researchers have found that improving frequency modulation, or FM, reception on cochlear implants and hearing aids may increase the quality of life for the millions of Americans who use these devices. Dr. Fan-Gang Zeng and his colleagues at UCI and the Peking Union Medical College Hospital in Beijing discovered that enhancing the detection of frequency modulation may significantly boost the performance of many hearing aids and automatic speech recognition devices by separating and blocking out background noise and increasing tonal recognition, which is essential to hearing music and certain spoken languages. Study results appear this week in the early online edition of Proceedings of the National Academy of Sciences. Some 30 million Americans have some form of hearing loss, and some 4 million of these people benefit from using hearing aids or cochlear implants. But limitation on sound quality and overamplification of background sound can hinder their uses. © Copyright 2002-2005 UC Regents

Keyword: Hearing
Link ID: 6756 - Posted: 06.24.2010

Children who live with younger siblings during the first six years of childhood are much less likely to develop multiple sclerosis later in life, a new study suggests. The finding backs the so-called "hygiene hypothesis" which proposes that exposure to infectious bugs early in life - lurking in household dirt or carried by younger siblings - reduces the risk of allergic and autoimmune diseases by stimulating the immune system. Multiple sclerosis (MS) is an autoimmune disease in which the body's immune system is thought to attack the fatty coat which insulates nerve cells. Damage to this sheath stops the nerves conducting electrical signals properly. The study showed that living with a toddler sibling for over five years could reduce the risk of developing MS by almost 90%. "This possibly occurs by altering childhood infection patterns and related immune responses," says Anne-Louise Ponsonby at the Australian National University in Canberra, who led the study. © Copyright Reed Business Information Ltd.

Keyword: Multiple Sclerosis
Link ID: 6755 - Posted: 06.24.2010

Monitoring the change in specific brain waves could be the first quantitative method for measuring libido, new research suggests. The technique measures attention, rather than sexual desire specifically, but Yoram Vardi, at Rambam Hospital and the Technion, both in Haifa, Israel told NewScientist: "We found that sexual stimuli are the most potent." So far 30 people with normal sexual function have been tested, but if further tests are successful, Vardi hopes his method will have many applications. These could include quantitatively analysing the libido-lowering (or enhancing) side effects of medication or even supporting legal claims of a reduction in sex drive after an accident. But he cautions that it is too early to say for sure whether it will be possible to establish an absolute measurement scale for libido. David Ralph, chairman of the British Society for Sexual Medicine, says the technique is "an interesting concept and the first of its kind - there has never been any quantitative measurement of libido". © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior
Link ID: 6754 - Posted: 06.24.2010

WEST LAFAYETTE, Ind. – Parts of the human brain think about the same word differently, at least when it comes to prepositions, according to new language research in stroke patients conducted by scientists at Purdue University and the University of Iowa. People who speak English often use the same prepositions, words such as "on," "in," "around" and "through," to indicate time as well as location. For example, compare "I will meet you 'at' the store," to "I will meet you 'at' 3 p.m." These examples show how time may be thought of metaphorically in terms of space. Just because it's the same word, however, doesn't mean the brain thinks about it the same way, said David Kemmerer, an assistant professor of psychological sciences and linguistics at Purdue's College of Liberal Arts. "There has been a lot of cognitive neuroscience research about how the brain processes language pertaining to concrete things, such as animals or tools," said Kemmerer, who also is an adjunct faculty member at the University of Iowa's Department of Neurology, where this research was conducted. "This is the first cognitive neuroscience study to investigate brain regions for spatial and temporal relations – those involving time – used in language.

Keyword: Language
Link ID: 6753 - Posted: 06.24.2010

Jessica Ebert Chimpanzees will tolerate unfair treatment, as long as it benefits someone they know well, say US researchers. This is the first time such behaviour has been demonstrated outside the human race. Sarah Brosnan and Frans de Waal, primatologists at Emory University in Atlanta, gave chimpanzees a piece of plastic and rewarded them for giving it back. If a subject is given a paltry payoff, such as a cucumber slice or celery stick, and it can see another getting a grape, the short-changed ape refuses to cooperate. But the strength of each chimpanzee's response depends on its social life. Those that had lived together for more than 30 years ignored the unequal treatment; whereas animals from a group formed eight years ago and pairs of chimpanzees reacted strongly, the researchers report in the Proceedings of the Royal Society B1. ©2005 Nature Publishing Group

Keyword: Evolution
Link ID: 6752 - Posted: 06.24.2010

Roxanne Khamsi Blind people have been shown to recruit visual areas of the brain to pinpoint the direction of sounds. The finding, published this week in PLoS Biology1, gives the first clear link between superior hearing abilities in blind people and increased activity in the visual centres of their brains. "These results tell us about the plasticity of the brain," says neuroscientist Franco Lepore of the University of Montreal, Canada. He believes that when people who were born blind, or went blind at a young age, use noise to navigate their environment, their mental processing adapts. Previous experiments have shown that people who lose their sight at an early age often excel at non-visual tasks, such as speech perception, verbal memory and musical ability. Some scientists have claimed that blind people can pinpoint sound in space better than the sighted. But other researchers have failed to find this advantage. Lepore and his colleagues decided to investigate why only some blind people are better at locating noises. ©2005 Nature Publishing Group

Keyword: Hearing; Vision
Link ID: 6751 - Posted: 06.24.2010

Map reading and parking may prove difficult for some women because they were exposed to too little testosterone in the womb, researchers suggest. The study, in the journal Intelligence, fuels the age-old male myth that women are deficient in these skills. Scientists from the University of Giessen, Germany, found a lack of the hormone affects spatial ability. Low testosterone levels are also linked to shorter wedding ring fingers, they say. The research looked at the spatial, numerical and verbal skills of 40 student volunteers. Spatial skill is the ability to assess and orientate shapes and spaces. Map reading and parking are spatial skills which men often say women lack. Women tend to disagree. The researchers also looked at the length of the students' wedding and index fingers. In women, the two fingers are usually almost equal in length, as measured from the crease nearest the palm to the fingertip. In men, the ring finger tends to be much longer than the index. For one of the spatial tests, volunteers had to tell which of five drawings could not be rotated so it looked like the other four. The other test involved the ability to think in 3D by mentally "unfolding" a complex shape. Overall, men achieved higher scores in the tests than women. But women with the male pattern of finger length did better than those whose wedding finger was shorter. They also scored better on the numerical tests. (C)BBC

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 6750 - Posted: 01.25.2005

By JONATHAN KOLATCH My introduction to floaters came on a sunny September afternoon in the orchard. I was high on a ladder picking Jonagold apples when I felt a pop in my left eye, followed by blurriness. I thought that maybe a branch had slapped across my glasses, dirtying the lens, and I went inside to clean it. But the blurriness - a sort of floating haze - persisted overnight. After hearing the symptoms, my ophthalmologist, Dr. William Kirber, diagnosed a posterior vitreous detachment, one of several causes of floaters, sensations that many people describe as specks, bugs or cobwebs floating in their fields of vision. In 85 percent of cases, the floaters caused by posterior detachment are mere annoyances, but when they occur suddenly, immediate medical examination is essential. The most common type of floater is caused by aging. Sitting directly between the lens and the retina is a cavity known as the vitreous or vitreous humor. Its outer boundary is defined by a crust like the skin of Jell-O. The function of the vitreous, which makes up four-fifths of the volume of the eye, is to give it its shape, to be a shock absorber in younger eyes and, some argue, to nourish the inner eye. Copyright 2005 The New York Times Company

Keyword: Vision
Link ID: 6749 - Posted: 01.25.2005

By NICHOLAS BAKALAR Old beagles, like old humans, act younger and smarter when they get the right diet and plenty of intellectual stimulation. A report published in the January issue of Neurobiology of Aging found that a diet rich in antioxidants combined with a stimulating environment slowed the canine aging process. The scientists divided the 48 beagles, ages 8 to 11, into four groups, giving them an enriched diet, an enriched environment, neither or both. The diet was fortified with vitamin E, vitamin C and other antioxidants. The dogs in the enriched environment group were housed with kennel mates, exercised twice a week for 15 minutes and challenged with tasks like learning to distinguish between a white box and a black box. By the end of the two-year trial, it was clear that the enriched diet alone and the enriched environment alone were each helpful in preventing decline. But the mental functioning of the dogs given a combination of enriched diet and stimulating environment was considerably higher than that of the dogs in the other three groups, the researchers found. One author of the paper works for the company that sells the dog food used in the study. Dr. William Milgram, the paper's lead author and a professor of psychology at the University of Toronto, said that one of the dogs, Scamps, "was basically a stupid dog." Copyright 2005 The New York Times Company

Keyword: Learning & Memory; Alzheimers
Link ID: 6748 - Posted: 01.25.2005