Infrared light probes tissue a slice at a time. GEOFF BRUMFIEL A new technique for probing tissue samples with lasers could give researchers easy access to three-dimensional images of brain samples and pieces of other organs. The system could replace the current methods of imaging soft tissue, says one of its developers Jeff Squier, a physicist at the Colorado School of Mines. Typically, samples are frozen, sliced and dyed, before being examined under the microscope. This process can distort key details. Squier's team places a fresh, dice-sized sample of rat brain tissue in front of a high-powered laser. The laser emits short, bright pulses of infrared light that stimulate fluorescent dyes that are either genetically engineered or manually brushed into the sample. The dye then emits light at a different wavelength that is picked up by detectors around the tissue. © Nature News Service / Macmillan Magazines Ltd 2003

Keyword: Brain imaging
Link ID: 3908 - Posted: 06.24.2010

Rodent study raises concerns about effect of cannabis on concentration. MICHAEL HOPKIN Cannabis makes rats lose track of time, a new study shows1. It robs rodents of the ability to discriminate between short and long periods. The discovery lends support to the suggestion that human cannabis users may be less adept at tasks that require sustained concentration. Most countries penalize possession of the drug, but there have been calls for tougher measures against driving while under its influence. "Any task that requires prolonged attention could be affected," says Jonathon Crystal of the University of Georgia, Athens, who led the study. Somebody driving after smoking marijuana, for example, could be perfectly capable of executing the required manoeuvres, but could be prone to disastrous lapses in concentration, he warns. © Nature News Service / Macmillan Magazines Ltd 2003

Keyword: Drug Abuse
Link ID: 3907 - Posted: 06.24.2010

ST. PAUL, MN – People with high levels of iron in their diet are more likely to develop Parkinson's disease, according to a study in the June 10 issue of Neurology, the scientific journal of the American Academy of Neurology. People with both high levels of iron and manganese were nearly two times more likely to develop the disease than those with the lowest levels of the minerals in their diets. The study compared 250 people who were newly diagnosed with Parkinson's to 388 people without the disease. Interviews were conducted to determine how often participants ate certain foods during their adult life. Those who had the highest level of iron in their diets – in the top 25 percent – were 1.7 times more likely to be Parkinson's patients than those in the lowest 25 percent of iron intake. Those whose level of both iron and manganese was higher than average were 1.9 times more likely to be Parkinson's patients than those with lower than average intake of the minerals.

Keyword: Parkinsons
Link ID: 3906 - Posted: 06.24.2010

MADISON - Scientists working with cells that may someday be used to replace diseased or damaged cells in the brain have taken neural stem cell technology a key step closer to the clinic. Writing in the current online edition (June 2003) of the Journal of Neurochemistry, scientists from the University of Wisconsin-Madison's Waisman Center describe the first molecular profile for human fetal neural stem cell lines that have been coaxed to thrive in culture for more than a year. The work is an in-depth analysis of global gene expression in human neural stem cells and demonstrates a method for prolonging the shelf life of cultured fetal stem cells, making it possible to generate enough cells to use to treat disease, says Lynda Wright, the lead author of the paper. Copyright © 2003 The Board of Regents of the University of Wisconsin System.

Keyword: Stem Cells; Regeneration
Link ID: 3905 - Posted: 06.24.2010

Researchers have identified a mechanism by which the eight amino acid peptide NAP, an active fragment of a neuroprotective brain protein, protects against alcohol-induced embryo toxicity and growth retardation in mice. Their findings bring alcohol researchers a critical step closer to developing pharmacologic agents to prevent alcohol-induced fetal damage. The study, funded by the National Institutes of Health’s National Institute on Alcohol Abuse and Alcoholism (NIAAA), the National Institute of Child Health and Human Development (NICHD), and the Medical Research Service, Department of Veterans Affairs, appears in the current issue of the Proceedings of the National Academy of Sciences.* The researchers produced NAP derivatives with specific substitutions and screened the compounds in cultured rat neurons for their protection against cell toxins and in whole mouse embryos for their protection against alcohol. By manipulating NAP’s structure and thereby altering its activity, the researchers were able to examine the ability of the different NAP derivatives to block alcohol inhibition of the L1 cell adhesion molecule. Their results indicate that NAP protects mouse embryos from alcohol toxicity by blocking alcohol effects on L1 rather than by its broad neuroprotective actions. "This elegant study demonstrates that the protective effect of NAP against alcohol damage differs from that of NAP against neurotoxins, said Ting-Kai Li, M.D., Director, National Institute on Alcohol Abuse and Alcoholism. "Ethanol inhibition of L1 is now strongly implicated in the pathogenesis of fetal alcohol damage and a foremost target of medication development."

Keyword: Drug Abuse; Development of the Brain
Link ID: 3904 - Posted: 06.24.2010

Many researchers have blamed the brain chemical, dopamine, as the major molecular underpinning of cocaine addiction. Cocaine increases the amount of dopamine available to send messages in the brain. Now increasing studies in animals show that another brain chemical, termed glutamate, which is known to aid memory, may be an equally or more important factor. The process of addiction is complex, but on a simple level, the findings may mean that glutamate oversees memories and learning tied to "cocaine-seeking." This new insight makes glutamate a prime target for drug development. The white powder may look as harmless as the sugar dusting on a donut, but friends and family of cocaine addicts know otherwise. People who try this drug often want to try it again. And again. With continued use they may become addicted. By definition, addicts have lost control of their drug use even in the face of negative physical, personal or social consequences. They devote every ounce of their being to finding and doing cocaine. Friends, family, work and school are no longer important. Copyright © 2003 Society for Neuroscience

Keyword: Drug Abuse
Link ID: 3903 - Posted: 06.24.2010

By DIANE CARDWELL Abby Bah, whose son Omar had high levels of lead in his blood, found out that the dust on the windowsills of her Brooklyn apartment had more than five times the amount of lead the Environmental Protection Agency deems safe. Cheri Lewis-Fontanez and her husband, David, learned that their 15-month-old son might be at an even greater risk, since the amount of lead discovered near the windows of their apartment nearby was more than 28 times greater than the safety threshold. The families live in two of the 59 apartments that were tested for lead in a three-month study in Bedford-Stuyvesant, where lead poisoning rates have remained high despite a steady citywide decline. The study, conducted by the Pratt Area Community Council using high school students trained in an E.P.A.-certified course, concludes that one of three children in the area lives in dangerous conditions. "The results of our study are shocking," said Gabriel Thompson, an author of the report, who is on the staff at the Community Council. "Our findings also have significance for residents of other Brooklyn neighborhoods, many of which have similar housing stock." Copyright 2003 The New York Times Company

Keyword: Development of the Brain
Link ID: 3902 - Posted: 06.10.2003

How facial muscles reveal--and hide--emotion By Carol Tavris Chelsea Thomas was born with Möbius syndrome, in which a nerve that transmits commands from the brain to the facial muscles is missing. As a result, for her first seven years Chelsea looked perpetually grumpy. Then surgeons transplanted nerves from Chelsea's leg to both sides of her mouth, and today Chelsea can do what most people in the world take for granted. She can smile. Meanwhile, thousands of adults are botoxing the nerves that allow them to frown. Actors who do so cannot convey anger or fear, and some botoxed mothers complain that their children no longer take their admonitions seriously, accompanied as they are by the mothers' bland expressions. Paul Ekman would not be surprised. He has been studying facial expression of emotions for some 30 years, in the noble tradition of Aristotle, who first observed the characteristic facial expressions of anger, fear "and all the other passions," and Charles Darwin, who added an evolutionary explanation. Darwin's theory of the universality of emotional expression was unpopular in the 1960s, when Ekman began his research. It was the era of the tabula rasa in social science; Ekman was to emotion what Harry Harlow was to love, swimming against the academic tides. As a graduate student at the time, I was in that tide up to my neck, and I remember how vehemently psychologists protested the idea that any aspect of human behavior might have a hardwired element. Facial expressions? Clearly cultural. Don't the Japanese coolly suppress any sign of emotion, and don't the Italians exuberantly reveal theirs? © 1996-2003 Scientific American, Inc.

Keyword: Emotions
Link ID: 3901 - Posted: 06.24.2010

By Mari Kane, AlterNet For eons, cannabis has been ingested for the treatment of common and chronic ailments, but now, the march of technology is propelling wacky tobaccy into a brave new century of pharmaceutical development. Scientists around the world are studying not only whole, smoked marijuana, but also pure extracts that would make Louis Armstrong blush. The fruits of their labors could hit European pharmacies as soon as next year. The leading-edge cannabis pharmaceutical company is the publicly-owned British firm, GW Pharmaceuticals. Their Cannabis Based Medical Extracts (CBME) have proven extraordinarily safe and effective in relieving medical conditions such as neuropathic pain and muscle spasms with effects occurring after 15-45 minutes depending on the patient's condition. The active ingredients in cannabis are Cannabinoids and the most potent ones are Tetrahydrocannabinol (THC) and Cannabinadiol (CBD). GWP has separated various Cannabinoids to determine which work best for specific ailments. Clinical trials have shown, for instance, that appetite was most improved with pure THC, but CBD also had an effect. They found the THC/CBD mix to work especially well for sleep improvement. © 2003 Independent Media Institute.

Keyword: Drug Abuse
Link ID: 3900 - Posted: 06.24.2010

Research Explains Why Most People Are Happy With Their Lives WASHINGTON — Surveys conducted in the United States and around the world consistently show that people are generally happy with their lives, even for those with physical and mental disabilities and people without much money. Researchers reviewing several studies on autobiographical memory and happiness have found that human memory is biased toward happiness and that mild depression can disrupt this bias for good over bad. The findings are published in the June issue of Review of General Psychology, a journal of the American Psychological Association (APA). In their article, W. Richard Walker, Ph.D., of Winston-Salem State University and colleagues find two causes for people’s recollection of the past to be positively biased. The first cause, according to their review of the research, seems to be due to the simple fact that pleasant events do in fact outnumber unpleasant events because people seek out positive experiences and avoid negative ones. Across 12 studies conducted by five different research teams, people of different racial and ethnic backgrounds and participants who ranged in age from late teens to early 50’s consistently reported experiencing more positive events in their lives than negative events. The other process at work involves our memory system treating pleasant emotions differently from unpleasant emotions. Seven studies reviewed by the researchers provide support for a fading affect for negative emotions. Pleasant emotions have been found to fade more slowly from our memory than unpleasant emotions. One mechanism for this uneven fading may involve a process known as minimization. In order to return to our normal level of happiness, we try to minimize the impact of life events. This minimization process – which occurs biologically, cognitively and socially -- is usually stronger for negative events than for positive events. © 2003 American Psychological Association

Keyword: Learning & Memory; Depression
Link ID: 3899 - Posted: 06.24.2010

John Travis Whether it's the whisper of a lover or the shouts of rapper Eminem, the hearing process works the same. Sound waves bend lashlike projections on cells within the inner ear, and these so-called hair cells respond by sending electrical impulses to the brain. Conventional wisdom holds that once damaged, hair cells in people and other mammals don't regenerate. But by using a virus to deliver a gene into the inner ear, scientists have now coaxed the ears of adult guinea pigs to sprout new hair cells. "It's the first time anyone has shown new hair cells can be grown in a mature mammalian ear," says Yehoash Raphael of the University of Michigan in Ann Arbor, who led the study. Copyright ©2003 Science Service.

Keyword: Hearing; Regeneration
Link ID: 3898 - Posted: 06.24.2010

By Jennifer Viegas, Discovery News — Human infants babble more precisely and baby birds sing better when they are engaged in positive social interaction with someone who cheers them on, according to a recent study. Previously it was thought that baby birds and humans only imitated their vocal cheerleaders, but the study suggests infants are also learning from non-vocal reactions to their sounds. The paper, published in the current Proceedings of the National Academy of Sciences, mentions baby birds sing a so-called plastic subsong, which is the equivalent of human baby gibberish. Copyright © 2003 Discovery Communications Inc.

Keyword: Language
Link ID: 3897 - Posted: 06.24.2010

By KATIE HAFNER ALBANY, Calif. The tumor, a subcutaneous growth the size of a Ping-Pong ball, must be removed. Dr. Tom Reed, the surgeon, puts on his gloves. His assistants have administered the anesthesia and shaved the patient's chest. Precise and efficient, Dr. Reed makes a cut no longer than three-quarters of an inch and gets to work. The mass he extracts is almost perfectly round and self-contained. The operation, which took less than four minutes, produces remarkably little blood. "He's so quick there's no time for blood," said Steve Gardner, a colleague of Dr. Reed's who has entered the operating room. Copyright 2003 The New York Times Company

Keyword: Miscellaneous
Link ID: 3896 - Posted: 06.08.2003

HANOVER, NH – Whether someone is looking directly at you or not when they are angry or afraid has an effect on how your brain interprets those expressions, says a group of Dartmouth researchers. In their study, the researchers found that the direction of another's gaze influences how your brain responds to fear and anger expressed by that person, specifically in your amygdala, which is the area in the brain that regulates emotions, detects potential threats and directs emotional behavior. Published in the June 6 issue of Science, the study reports that when viewing pictures of angry expressions, people exhibit more amygdala activity when the angry person in the picture is looking away. When viewing expressions of fear, the amygdala is more active when there is direct eye contact. This study is the first to demonstrate that gaze direction is an important signal in how we perceive facial expressions, according to the authors. "Some people may be surprised to learn that the amygdala actually responded most when threat cues were ambiguous," said Reginald Adams, a former Dartmouth graduate student and the lead author on the paper. "This may indicate that the amygdala perceives heightened threat in uncertainty, or that the amygdala has to work harder to make sense of the ambiguity surrounding the threat."

Keyword: Emotions
Link ID: 3895 - Posted: 06.24.2010

Neuroscientists at NYU and Harvard identify cells in the hippocampus that signal new memory formation Neuroscientists at NYU and Harvard have identified how the brain’s hippocampus helps us learn and remember the sights, sounds and smells that make up our long-term memory for the facts and events, termed declarative memory. By studying the activity of neurons of the hippocampus, the scientists have illuminated how the brain signals the formation of new associative memories, a form of declarative memory. These results provide some of the strongest direct evidence to date for learning-related plasticity in the hippocampus. The research findings are reported in the June 6 issue of the publication Science in a paper entitled “Single Neurons in the Monkey Hippocampus and the Learning of New Associations.” Since the 1950s, scientists have been aware of the link between the hippocampus and memory, but knew little of how this association manifested itself in neural activity. The NYU research team, led by NYU post-doctoral fellow Sylvia Wirth, NYU professor Wendy Suzuki and graduate student Marianna Yanike, examined the neural correlates of associative memory formation by using electrodes to monitor the electrical activity of individual neurons in the brains of monkeys performing an associative learning task. The neural and behavioral data was analyzed using dynamic estimation algorithms developed by post-doctoral fellows Loren Frank, Anne Smith and professor Emery Brown at Harvard University.

Keyword: Learning & Memory
Link ID: 3894 - Posted: 06.24.2010

For decades, scientists have disagreed about the way the brain gathers memories, developing two apparently contradictory concepts. But newly published research by a team of scientists at Rutgers-Newark's Center for Molecular and Behavioral Neuroscience (CMBN) indicates that both models of memory may be partially correct – and that resolving this conflict could lead to new approaches for the treatment of memory disorders such as Alzheimer's Disease. The dispute has centered on how the hippocampus – a structure deep inside the brain – processes new information from the senses and stores it. Some researchers – such as Mark Gluck and Catherine Myers, co-directors of the Memory Disorders Project at the CMBN – have been proponents of "incremental memory," viewing the acquisition of memory as a learning process that occurs over time. "If you see thunder and lightning occur together once, that may be seen as a coincidence," Myers observed. "But the more often you see them happen at the same time, the more likely you are to remember them as related parts of one event."

Keyword: Learning & Memory
Link ID: 3893 - Posted: 06.24.2010

Scientists have discovered a drug which can help people with a potentially life-threatening sleep disorder - and which could even help heavy snorers. Sleep apnoea causes a person to stop breathing for up to a minute when airflow from the nose and mouth to the lungs is restricted during sleep. It can happen hundreds of times in a night. Sleep apnoea affects around 1% of middle-aged men in the UK. It is linked with an increased risk of high blood pressure, heart attack, stroke and adult-onset diabetes. It can also be linked to behavioural problems and learning difficulties because people do not get enough rest. Sleep apnoea can only currently be managed using often uncomfortable devices such as masks or nasal prongs. But US researchers have found that an antidepressant called mirtazapine can significantly reduce the symptoms of sleep apnoea. (C) BBC

Keyword: Sleep; Depression
Link ID: 3892 - Posted: 06.05.2003

About one in one thousand babies born in the U.S. each year is completely deaf. Another two or three per thousand have some hearing loss. As this ScienCentral News video reports, researchers at the University of Colorado have found that the earlier hearing loss is discovered the better. When Elise Nowicki was about 7 months old, her parents, Brenda and Lee, started to suspect that she couldn’t hear. © ScienCentral, 2000-2003.

Keyword: Hearing
Link ID: 3891 - Posted: 06.24.2010

La Jolla, Calif.—Manufacturing motor nerve cells may someday be possible to help restore function in victims of spinal cord injury or such diseases of motion as Parkinson’s and Lou Gehrig’s disease or post-polio syndrome, a Salk Institute research study has found. Salk Associate Professor Sam Pfaff and postdoctoral fellow Soo-Kyung Lee reported in a paper in the June 5 issue of Neuron that they constructed a detailed model of how stem cells are prodded, regulated and otherwise encouraged to become not only nerve cells, but specifically motor neurons that the body relies on to move muscles and limbs throughout the body. The study provides the first blueprint for the cellular factory that produces motor neurons from embryonic stem cells. It could eventually result in new treatments for spinal cord injury, and other diseases that affect motor nerve cells.

Keyword: ALS-Lou Gehrig's Disease ; Stem Cells
Link ID: 3890 - Posted: 06.24.2010

Eating methylmercury contaminated fish causes problems in adults Warnings about methylmercury contaminated fish are not just for young children and expectant mothers, according to new research published today in Environmental Health: A Global Access Science Source. Adults who regularly eat contaminated fish could find that their concentration, dexterity and verbal memory are impaired. The major source of methylmercury is diet, particularly large fish like shark and swordfish. The authors of this new research concluded: "methylmercury exposure at levels often encountered by adults in North America may be inducing adverse effects on neurobehavioral performance." Methylmercury damages or destroys nerve tissue. It affects the visual cortex and the cerebellum, the part of the brain responsible for controlling complex movements and maintaining balance. This new research challenges the assumption that adults are much less sensitive to its toxic effects than children.

Keyword: Development of the Brain; Intelligence
Link ID: 3889 - Posted: 06.05.2003