Drawing on experiments with blue jays, a team of University of Minnesota researchers has found what may be the evolutionary basis for impulsive behavior. Such behavior may have evolved because in the wild, snatching up small rewards like food morsels rather than waiting for something bigger and better to come along can lead to getting more rewards in the long run. The work may help explain why many modern-day humans find it so hard to turn down an immediate reward--for example, food, money, sex or euphoria--rather than investing and waiting for a bigger reward later. The work will be published in the Dec. 7 issue of the Proceedings of the Royal Society (London). In experiments with blue jays, David Stephens, a professor of ecology, evolution and behavior in the university's College of Biological Sciences, found that birds presented with a choice of getting a small food reward immediately or waiting a short time for a bigger one could not be trained to wait, even after a thousand repetitions. Many researchers have explained such impulsiveness as the result of the bird "discounting" the value of a delayed reward--that is, instinctively realizing that a reward delayed may be a reward denied because conditions can change while the bird is waiting. But the birds' impulsiveness was simply too strong to explain that way, Stephens said. "I think we were asking them the wrong question," he explained. "In nature, they don't often encounter a situation where they must give up a better, but delayed, food morsel when they grab a quick meal. So we designed an experiment that better modeled real life in the wild."

Keyword: Evolution; Drug Abuse
Link ID: 6545 - Posted: 12.07.2004

By MARY DUENWALD The women in the television commercial pull up their shirts to display the words "abdominal pain," "bloating" or "constipation" scrawled in black marker on their abdomens. Some viewers probably respond by reaching for the remote control. But others may be prompted to ask their doctors whether Zelnorm, the Novartis drug in the advertisement, can actually ease the symptoms of irritable bowel syndrome. The answer, experts say, is, "It depends." Zelnorm is one of two drugs - the other is Lotronex from GlaxoSmithKline - approved by the Food and Drug Administration for the treatment of irritable bowel syndrome, or I.B.S., a disorder that is estimated to affect about 45 million Americans. Twice as many women as men suffer from it. Their search for relief is often frustrating, because it has no single cause and no cure, and doctors are sometimes dismissive of patients' complaints. The symptoms vary. About a third of sufferers have constipation, another third have diarrhea and the rest alternate between the two. Bloating after meals and lower abdominal pain are also common, as are severe fatigue, sleep difficulties, low interest in sex, hopelessness and tension, a recent study in The Archives of Internal Medicine says. Copyright 2004 The New York Times Company

Keyword: Pain & Touch
Link ID: 6544 - Posted: 12.07.2004

By LAURIE TARKAN By listening intently to movements and heartbeats, researchers are finding that the fetuses of mothers who are stressed or depressed respond differently from those of emotionally healthy women. After birth, studies indicate, these infants have a significantly increased risk of developing learning and behavioral problems, and may themselves be more vulnerable to depression or anxiety as they age. The studies, researchers caution, are preliminary. Stress or depression during a mother's pregnancy is only one among many influences that affect an infant's development. Even among mothers who are depressed or highly stressed, the rate of emotional and behavioral problems in children is still very low. "The last thing pregnant women need is to have something else to worry about," said Dr. Janet DiPietro, a developmental psychologist at the Johns Hopkins University Bloomberg School of Public Health. The studies reflect growing evidence that stress and depression can have early and lasting effects on a child's life. Copyright 2004 The New York Times Company

Keyword: Depression; Development of the Brain
Link ID: 6543 - Posted: 12.07.2004

Not getting enough shut-eye could be interfering with your ability to shed unwanted pounds. Previous research has shown that sleep could be a key regulator of body weight and metabolism. New findings link changes in two important appetite-regulating hormones to the amount of sleep people regularly get. Shahrad Taheri, now at the University of Bristol, and colleagues analyzed data collected on 1,024 volunteers as part of the Wisconsin Sleep Cohort Study. Starting in 1989, the subjects filled out questionnaires and kept diaries that logged their sleep habits. In addition, once every four years they had their blood sampled and underwent tests that measured physiological variables while they slept. The researchers report today in the journal Public Library of Science: Medicine that people who consistently slept less than five fours a night had significant differences in the hormones leptin and ghrelin as compared with people who slept an average of eight hours a night. Leptin is produced by fat cells. Low levels of it are a signal of starvation and a need for a bigger appetite. Ghrelin, meanwhile, is produced by the stomach and is an appetite stimulant--the more ghrelin you have, the more you want to eat. The study subjects suffering a lack of sleep had 16 percent less leptin and nearly 15 percent more ghrelin than those who were well rested did. "In Western societies, where chronic sleep restriction is common and food is widely available, changes in appetite regulatory hormones with sleep curtailment may contribute to obesity," the team reports. © 1996-2004 Scientific American, Inc.

Keyword: Sleep; Obesity
Link ID: 6542 - Posted: 06.24.2010

More than fifteen thousand people in the U.S. die each year in alcohol-related motor vehicle crashes, accounting for around 40 percent of all traffic-related deaths. In 2003, a quarter of drivers aged 15 to 20 who died in traffic accidents had been drinking. As part of the on-going Seattle Social Development Project, sociologist Sabrina Oesterle and her colleagues at Social Development Research Group at the University of Washington in Seattle looked at the long-term health effects of adolescent binge drinking. "We already know that binge drinking in adolescence has immediate health consequences for teenagers," says Oesterle. "So we were especially interested in whether drinking, especially heavy drinking in adolescence, has long-term health consequences that we could see in young adulthood." They also found that about a quarter of the children fell into a group who were more likely to drive drunk or under the influence of drugs. Conducting a series of interviews on alcohol, tobacco and drug use, the study followed more than 800 children in 18 elementary schools from the 5th grade through to the age of 24. Oesterle defined bingeing, or heavy episodic drinking, as five or more alcoholic drinks on one occasion in a month. "Our findings show that a history of binge drinking in adolescence has long-term health outcomes in young adulthood at age 24," she says. © ScienCentral, 2000- 2004.

Keyword: Drug Abuse
Link ID: 6541 - Posted: 06.24.2010

Roxanne Khamsi The inhabitants of China appreciated a tipple as much as 9,000 years ago, according to an analysis of pottery shards from the period. Chemical residues reveal that the pots were used to hold a drink made with rice, honey and fruit, and are the earliest direct evidence for brewed beverages. Throughout history, human societies have used the process of fermentation to create alcoholic drinks. But how this practice first evolved has remained elusive. In some areas, ancient texts provide clues. The oldest surviving recipe in the world comes from a 3,800-year-old clay tablet of Sumer, a civilization from the area that is now southern Iraq. Part of a hymn to the goddess of brewing gives details about how to make beer. Oracle inscriptions dating back China's late Shang dynasty (about 1200-1046 BC) also describe alcoholic beverages. Experts believe that fermented drinks probably existed in China and elsewhere much more than 3,000 years ago. But until now they have relied only on the shape and styles of pottery vessels to support this idea. ©2004 Nature Publishing Group

Keyword: Drug Abuse
Link ID: 6540 - Posted: 06.24.2010

Monkeys may visualise a predator or food in response to calls from other monkeys, US researchers say. Alex Martin and colleagues at the National Institute of Mental Health in Maryland, US, played coos and screams recorded in the wild to captive rhesus monkeys - held stationary - and used a positron emission tomography (PET) scanner to monitor their brain activity. The calls elicited increased activity in areas of the brain associated with vision, visual memory and movement in humans - the posterior visual-processing regions and the middle temporal and medial superior temporal areas. Screams also activated parts of the brain which in humans are linked to emotion. Although it is not certain this mental activity corresponds to images flashing through a monkey's mind, Martin says it shows both rhesus monkeys and humans have a similar basic framework for responding to calls. So rhesus monkeys could perhaps provide insight into the evolution of conceptual thought - and even language - in the human brain, he adds. © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 6539 - Posted: 06.24.2010

By Molly Masland As concern over Alzheimer’s disease grows, more Americans are turning to expensive and potentially unsafe supplements that claim to enhance memory. But prevention of age-related memory loss may be no further away than your refrigerator, and no more expensive than a bag of groceries, experts say. With the aging population of baby boomers in the United States, more research is being done than ever before on diseases such as Alzheimer’s and other forms of dementia. Scientists are developing a better understanding of why memories fade, and along the way they are finding new ways to combat the decline. For one thing, research increasingly suggests that diet may be important in preventing Alzheimer's. As the brain ages, it loses the ability to protect itself from the barrage of commonplace dangers it faces every day, particularly inflammation and oxidation, a process which allows damaging free radicals to attach themselves to cells. While it's not entirely clear what causes Alzheimer's disease, amyloid plaque — a goopy, fibrous substance akin to fur balls in the brain — plays a key role. As the plaque builds up, it causes more oxidation and inflammation, and begins to kill off brain cells. © 2004 MSNBC Interactive

Keyword: Learning & Memory; Alzheimers
Link ID: 6538 - Posted: 06.24.2010

Doctors have been issued with new guidance on the prescribing of antidepressants. The National Institute for Clinical Excellence guidelines say doctors should exercise more caution in prescribing the drugs. Separate advice from the Medicines and Healthcare Products Regulatory Authority calls for stronger warnings on drugs such as Prozac and Seroxat. It says advice on potential withdrawal symptoms should be reinforced. One woman in 15 and one man in 30 are affected by depression each year. And around 44 adults in every thousand are estimated to have an anxiety disorder. The NICE guidelines say no type of antidepressant should be used in the initial treatment of mild depression. But for patients with moderate to severe depression who are deemed to need antidepressants, drugs such as Prozac and Seroxat should be favoured above other types because they are less likely to be discontinued due to side-effects. Both belong to a family of drugs known as Selective Serotonin Reuptake Inhibitors (SSRIs). Around 13 million prescriptions are written for SSRIs in Britain annually. They have become increasingly popular over the last decade, as doctors considered them safer than the older tricyclic drugs which carried a high risk of overdose. However, last year the MHRA banned the prescription of all SSRIs except Prozac to under 18s after concerns the drugs could make some suicidal. People who are on SSRIs are advised not to stop taking them, or reduce their dose, without speaking to their GP. (C)BBC

Keyword: Depression
Link ID: 6537 - Posted: 12.06.2004

An antibiotic used to treat leprosy and tuberculosis is showing promise as a therapy for Parkinson's disease. In laboratory tests, rifampicin was found to prevent the formation of protein fibrils associated with the death of brain cells in Parkinson's. Researchers from the University of California, Santa Cruz, also found the drug dissolved existing fibrils. The research, which is still at an early stage, is published in the journal Chemistry and Biology. The researchers studied the effects of rifampicin in test-tube experiments and are currently doing studies with cell cultures and mice to see if the same effects occur in living cells. Researcher Professor Anthony Fink said: "Clearly more work is needed to determine if this would work therapeutically, but if it does it would probably be most useful as a prophylactic therapy used in the early stages of the disease, before there is general neurological damage. "The disaggregation of existing fibrils is probably the most interesting and novel finding in this study. "If it works in people, that would really open up the possibility of stopping the progression of Parkinson's disease when it is first diagnosed." Parkinson's is a progressive movement disorder resulting from the death of nerve cells in the brain which produce a key chemical called dopamine. It is thought a critical step in the development of the condition is the collection of a protein, known as alpha-synuclein, into insoluble fibrils. Certainly, deposits called Lewy bodies, composed mostly of alpha-synuclein fibrils, appear in affected nerve cells. Some people believe the fibrils themselves are toxic and cause brain cells to die, others that the toxic agents are smaller component parts formed earlier in the process. Previous research has found that rifampicin may also prevent the formation of the protein deposits associated with Alzheimer's disease. (C)BBC

Keyword: Parkinsons
Link ID: 6536 - Posted: 12.06.2004

Scientists believe they have worked out exactly how we recognise a face when we see it. Experts have known for some time that there is something special about faces that draws us to look at them, even after the first few hours of birth. A brain region called the fusiform face area (FFA) has been pinpointed as key. Now a team at Massachusetts Institute of Technology say in the journal Neuron that they have figured out how the FFA processes this visual information. To find out what was going on in the brain, the researchers asked volunteers to take part in an experiment. The volunteers were asked to look at pictures of different faces and also pictures of an inanimate object - a house. At the same time, the volunteers' brains were scanned using functional magnetic resonance imaging (fMRI), which shows up which areas of the brain are active at any given time. Some of the faces that the volunteers looked at were completely normal, while others had features that were spaced differently or had features that were replaced by those of different faces, such as a different nose or mouth. (C)BBC

Keyword: Vision
Link ID: 6535 - Posted: 12.06.2004

By CATHRYN JAKOBSON RAMIN A few months ago, as I trudged down the stairs of my office building, deep in my thoughts, I noticed a dark-haired woman waving to me from the window of her car. She looked vaguely familiar, but I couldn't place her. Like quite a few others, she had slipped out of my mental Rolodex. In my brain, the synaptic traces that connected us had frayed. Yet again, I had misplaced an entire human being. ''So wonderful to see you,'' she said, inquiring by name after every member of my family, including the two dogs. Apparently she was not a casual acquaintance. Fending off panic, I proceeded through a mental list: Work? School? Synagogue? I couldn't visualize her in these places. I was about to cut and run with a quick ''nice to see you, too'' when the rear window slid down, revealing a toothy grin. ''We've been to the orthodontist,'' she said. The minute I saw Sam's freckled face, the mystery was solved. Our sons were best pals in nursery school and kindergarten. I had sat in her kitchen, discussing birthday parties. I remembered her backyard dotted with Little Tikes plastic play furniture. I knew what she did for work, and the name of her Portuguese nanny. ''Lisa,'' I said, as if her identity had never eluded me, ''it's terrific to see you.'' Copyright 2004 The New York Times Company

Keyword: Learning & Memory; Alzheimers
Link ID: 6534 - Posted: 12.06.2004

Mark Peplow A preservative commonly found in cosmetics such as shampoo and moisturizers harms developing nerve cells, according to a controversial study. But claims that the compound may therefore pose a risk to unborn babies have provoked concern from other scientists, who are worried that such assertions may create unnecessary panic. Methylisothiazolinone (MIT) is widely used in hand creams, shampoos and other cosmetics. It kills bacteria, making it easier to store the lotions for longer periods of time without colonies of microbes developing. Safety tests have previously found that the chemical may cause slight skin irritation in susceptible people1. But Elias Aizenman, a neurobiologist at the University of Pittsburgh, Pennsylvania, says that he could not find any information about the chemical's impact on developing nerve cells. So his research team has been studying how the chemical affects neurons taken from the brains of rat embryos. Preliminary research published in 2002 found that relatively large doses of MIT killed most of the neurons within ten minutes2. Many chemicals are toxic in high enough doses, however, so Aizenman's group went on to test much lower doses over longer periods of time. This mimics the occupational exposure of people who work with MIT every day, for example in factories that make cosmetic products. ©2004 Nature Publishing Group

Keyword: Development of the Brain; Neurotoxins
Link ID: 6533 - Posted: 06.24.2010

WASHINGTON -- New MRI-based studies present more evidence that the brains of chimpanzees are human-like in terms of the relationships among brain asymmetry, handedness and language, according to research undertaken at the Yerkes National Primate Research Center in Atlanta. Understanding our evolutionary cousins helps us to understand what makes us human. Two related reports appear in the December issue of Behavioral Neuroscience, which is published by the American Psychological Association (APA). In the first study, Hani Freeman, BA, Claudio Catalupo, PhD (also with Georgia State University), and William Hopkins, PhD (also with Berry College), took magnetic resonance images of 60 chimpanzees to measure the anatomy of two key structures in their brains' limbic systems, an early-evolving central region that includes the hippocampus and amygdala. In the MRI pictures, the hippocampus (which regulates learning and consolidation of spatial memory, mood, appetite and sleep) was asymmetrical, its right half significantly larger than its left. This asymmetry was bigger in males. These findings are consistent with studies of human hippocampi, which are also asymmetrical. At the same time, just as in humans, the amygdalas of the chimps were symmetrical. Studies such as this confirm that human and chimp brains are not only asymmetrical, but asymmetrical in the same way. The findings echo previous looks at the non-limbic parts of chimpanzee brains, which also appear human-like in their patterns of asymmetry. This fact, especially if studied in the context of functional behaviors that reflect asymmetries, may help scientists get a better fix on the evolution of the limbic system in all primates, including humans.

Keyword: Laterality
Link ID: 6532 - Posted: 12.06.2004

Heather Tomlinson A multiple sclerosis treatment made from cannabis has been rejected by UK regulators, outraging patient groups who say it has benefits for sufferers. The news that Sativex cannot go on sale sent the shares of GW Pharmaceuticals, the company developing the drug, down 25% to close at 106.5p. The news precedes a meeting between Home Office and Department of Health ministers next week. The meeting was prompted by MPs' concerns that MS sufferers are having to buy cannabis off the street to relieve their symptoms. The meeting had planned to look at ways of getting the treatment out more quickly. "The [regulator] has failed to listen to those with MS who reported positive and sustained benefit from Sativex, in a properly designed and statistically significant trial," said Christine Jones, the chief executive of the MS Trust. "I hope the [regulator] will reconsider their position and give some thought to the impact of this decision on the lives of those with painful, chronic disease." The MS Society said the news was "extremely disappointing". Sativex is a nasal spray made from extracts of cannabis plants, which the Home Office allows GW to farm for medical purposes. It contains THC - the compound in cannabis that causes the "high". © Guardian Newspapers Limited 2004

Keyword: Multiple Sclerosis; Drug Abuse
Link ID: 6531 - Posted: 06.24.2010

Cost and Risk Questions Mount in Face Of Overall Surge in Prescription Drugs By Shankar Vedantam, Washington Post Staff Writer One in 10 American women takes an antidepressant drug such as Prozac, Paxil or Zoloft, and the use of such drugs by all adults has nearly tripled in the last decade, according to the latest figures on American health released yesterday by the federal government. Those numbers are among a broad array of changes in health and health care use in the United States identified in the report. It confirmed that prescription drug costs are soaring faster than any other area of medical care as ever-increasing numbers of Americans take drugs for psychiatric conditions, to lower their cholesterol, to control asthma and for a wide range of other reasons. In 2002, the latest year for which data were available, the total tab for health care soared to $1.6 trillion -- of which prescription drugs accounted for $162 billion, the report found. Drug costs rose by 15 percent over the year before, driven by a combination of more expensive medicines and increased use. The report comes at a time when questions are growing about the costs and safety of many prescription drugs. The Food and Drug Administration recently concluded that antidepressants can increase the risk of suicidal behavior among children, and the manufacturer of Vioxx abruptly recalled the popular painkiller for safety reasons. A senior FDA official testified in Congress last month that he believes five other approved drugs are dangerous and should be taken off the market. © Copyright 1996-2004 The Washington Post Company

Keyword: Depression
Link ID: 6530 - Posted: 06.24.2010

Salvation Army bells, the blare of shopping mall carols, restaurants roaring with holiday cheer. These aren't sounds likely to send nerves into an irritated frenzy. But the days following gift giving might, as a dazzling display of the latest electronics enters some homes, decibels blazing, adding to a cacophony that researchers say is only getting worse. "Just about everything is making extra noise nowadays," says Purvis Hobson Bedenbaugh, a neuroscientist at the McKnight Brain Institute at the University of Florida. "Just all kinds of things like refrigerators, electric razors, hairdryers, bigger cars with bigger engines, more cars on the freeway." Bedenbaugh conducted research on how background noise effects lab rats and believes that a bombardment of sound might not only disturb the peace, it may also scramble some people's brain signals. To reveal how, his team wired rats' auditory thalamus, the part of the brain that helps process sound. As rats listened to a strong foreground noise they also heard three types of background noise—one similar to static, one to the murmur of conversation and one akin to the whir of a rewinding tape recorder. Bedenbaugh recorded the rats' brain responses and compared them with the response of the same rats when they weren't listening to background noise. The process went awry in rats that listened to background noise. © ScienCentral, 2000- 2004

Keyword: Hearing; Stress
Link ID: 6529 - Posted: 06.24.2010

Susan Milius After more than 10 years of searching, researchers have identified a compound produced by the senior workers in a honeybee colony that prolongs the time that teenage bees stay home babysitting. Honeybee workers spend their first few weeks as young adults tending the colony's brood and then shift jobs to foraging for food outside the colony. Studies had predicted that established foragers pass along a pheromone that slows their younger sisters' career change, according to Gene E. Robinson of the University of Illinois at Urbana-Champaign. That pheromone turns out to include ethyl oleate, possibly conveyed to the teens during mouth-to-mouth food transfer, Robinson and an international team of colleagues report in an upcoming Proceedings of the National Academy of Sciences. The pheromone guides the division of labor. "When we think about this with a human bias, it seems like a problem that requires centralized control. But it's decentralized," says Robinson. Should the colony run low on mature foragers, the supply of grow-slow pheromone dwindles, and young bees mature rapidly to fill in the ranks. When foragers abound, an abundance of the pheromone slows the replacement process. Copyright ©2004 Science Service.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 6528 - Posted: 06.24.2010

Christen Brownlee A new study puts evidence behind the old adage that stressful experiences can give a person gray hairs. Scientific data now indicate that prolonged psychological stress might cause a person's cells to age, and possibly die, significantly faster than normal. Previous research had shown that protein-DNA complexes called telomeres serve as a cell's timekeeper, telling it how long to live. Telomeres protect the ends of chromosomes, much as plastic tips protect shoelaces. Each time a cell divides, enzymes chew off a tiny portion of its telomeres. When the caps are whittled down to nubs, cells cease dividing and soon die. Scientists have long known that stress can harm a person's health by, for instance, lowering immunity or raising blood pressure. "We wanted to look at some of the molecular underpinnings of why that might be true. No one actually has clear ideas," says Elizabeth Blackburn of the University of California, San Francisco. Blackburn and her colleagues examined whether telomeres might play a role. Her team recruited 58 healthy women between the ages of 20 and 50. While all the women were mothers of at least one child, 39 members of the group were primary caregivers for a child who was chronically ill with a disease such as cerebral palsy. Copyright ©2004 Science Service.

Keyword: Stress
Link ID: 6527 - Posted: 06.24.2010

Paralysed dogs given an unusual treatment for spinal cord injury have shown some success in being able to walk again, a new study reveals. Dogs rendered paraplegic by severe spinal cord injuries regained significant neurological function after treatment with a polymer called polyethylene glycol, or PEG, say researchers at Purdue University in Indiana, US. Dogs admitted to two veterinary hospitals with paraplegia - caused by naturally occurring mishaps leading to “explosive” ruptures of spinal discs - were initially treated with intravenous injections of PEG. This was followed by standard treatments, such as surgery to relieve pressure on the spinal cord and remove stray bone fragments, and steroids to reduce inflammation. The team, led by Richard Borgens of Purdue’s Center for Paralysis Research, reports that the PEG-treated animals showed marked improvement compared to “historical controls” - paraplegic dogs whose progress had been documented at the hospitals following standard treatments in the 1990s. Within 48 hours, the PEG-treated dogs scored far better than the historical controls on neurological and behavioural tests designed to measure early functional recovery. And by six weeks after treatment 68% of the PEG-treated dogs were able to walk, compared with only 24% of the historical controls. © Copyright Reed Business Information Ltd.

Keyword: Regeneration
Link ID: 6526 - Posted: 06.24.2010