By Maggie Fox, Health and Science Correspondent WASHINGTON (Reuters) - A study of the brains of primates ranging from tiny bush babies to humans and apes shows that size really may matter, researchers said on Monday. All primates have an unusually large frontal cortex, a part of the brain used by humans for higher thought and reasoning, they found. From lemurs to chimpanzees, that part of the brain is especially large compared with overall brain size, the California Institute of Technology team found. "In primates, having a bigger brain means you have a disproportionately larger frontal cortex," said Eliot Bush, a PhD candidate at Caltech who worked on the study. Copyright © 2004 Yahoo! Inc.

Keyword: Evolution
Link ID: 5111 - Posted: 06.24.2010

By LAWRENCE K. ALTMAN — Among teenagers who pledged not to have sex before marriage, a majority did not live up to their vows, according to a national study reported here on Tuesday. The teenagers also developed sexually transmitted diseases at about the same rate as adolescents who had not made such pledges. But a pledge to refrain from premarital sex, the researchers found, did tend to delay the start of sexual intercourse by 18 months. The adolescents who took virginity pledges also married earlier and had fewer sexual partners than the other teenagers surveyed, said Dr. Peter Bearman, the chairman of the sociology department at Columbia University and the lead author of the study. Of the 12,000 teenagers included in the federal study, 88 percent of those who pledged chastity reported having had sexual intercourse before they married, Dr. Bearman said at a scientific meeting in Philadelphia on preventing sexually transmitted diseases. Copyright 2004 The New York Times Company

Keyword: Sexual Behavior
Link ID: 5110 - Posted: 06.24.2010

Scientists are developing a pill that helps people quit smoking and slim down at the same time. The drug, rimonabant, works by blocking the circuits in the brain that control the urge to eat and smoke. Obesity and smoking have become two of the world's biggest killers, and are being targeted for action in the UK. The makers, French firm Sanofi-Synthelabo, hope to market the drug next year. In one trial the drug helped people to shed an average of 9kg (20lbs) in a year. And in a second, it was found to double the chances of smokers successfully quitting - at least in the short term. Dr Robert Anthenelli, of the University of Cincinnati, who directed the smoking study, said: "We think this might be the ideal compound for people who are overweight and smoke." (C)BBC

Keyword: Drug Abuse; Obesity
Link ID: 5109 - Posted: 03.10.2004

Scientists decode a critical gene that may have led to the evolution of our big brains By Zach Zorich Scientists have long suspected that humans evolved large brains because our hominid ancestors had to outwit and elude predators, learn to use fire, and develop complex social structures. The smart hominids survived, while the stupid ones were more likely to get eaten or freeze to death. Over millions of years, the result of this game of survival of the fittest was the appearance of big-brained, peculiarly intelligent modern humans. Now Bruce Lahn, a biomedical researcher at the University of Chicago, has found the first clear indication of the genetic changes that led to the rapid expansion of our brain. Lahn and his colleagues looked at the abnormal spindle-like microcephaly associated (ASPM) gene, which scientists had previously identified as a key player in brain development. He grew intrigued by ASPM after other researchers discovered that serious defects in the gene cause microcephaly—a drastic reduction in the size of the brain’s cerebral cortex, the region responsible for such higher brain functions as abstract thought and planning. Lahn wondered: Could changes in this gene, favored by the pressures of natural selection, have directed the development of the big, modern human brain? © 2003 The Walt Disney Company.

Keyword: Evolution; Development of the Brain
Link ID: 5108 - Posted: 06.24.2010

Newborns whose mothers drank alcohol heavily during pregnancy had damage to the nerves in the arms and legs, according to a study by researchers at the National Institute of Child Health and Human Development, one of the National Institutes of Health. The study was conducted in collaboration with researchers at the University of Chile. The nerve damage was still present when the children were reexamined at one year of age. The study is the first to examine whether exposure to alcohol before birth affects the developing peripheral nervous system — the nerves in the arms and legs, rather than in the brain or spinal cord. The study appears in the March issue of the Journal of Pediatrics. "Infants born to mothers who drink heavily during pregnancy are known to be at risk for mental retardation and birth defects, said Duane Alexander, M.D., director of the NICHD. "This is the first study to show that these infants may suffer peripheral nerve damage as well."

Keyword: Development of the Brain; Drug Abuse
Link ID: 5107 - Posted: 06.24.2010

Scientists have identified a gene in mice that is necessary for normal brain development and may contribute to the most common form of primary brain tumors in children. Dr. Valeri Vasioukhin and colleagues at the Fred Hutchinson Cancer Research Center have discovered that a gene known as "lethal giant larvae 1" (a.k.a. Lgl1) plays a critical role in shaping cell behavior during embryonic brain development. Lgl1 was initially identified in the fruit fly Drosophila, where it regulates cell polarity (the overall directionality of a cell) as well as cell proliferation. Dr. Vasioukhin and colleagues now show a similarly important role for Lgl1 in the mammalian brain. To gain insight into Lgl1 function in mammals, Dr. Vasioukhin and colleagues generated mice specifically lacking the Lgl1 gene. These Lgl1-knockout mice – as they are known – developed normally at first, but by day 12.5 of gestation exhibited dramatic abnormalities. Lgl1-mutant pups have a dome-shaped head, severe hydrocephaly and die within 24 hours after birth. Internally, there is an expansion of the striatum region of the brain, along with the formation of abnormal cell groupings called rosettes.

Keyword: Development of the Brain; Genes & Behavior
Link ID: 5106 - Posted: 06.24.2010

Scientists have been studying cannabinoids, substances that are chemically related to the ingredients found in marijuana, for more than two decades, hoping to learn more about how the drug produces its effects--both therapeutic and harmful. Marijuana has been reported effective in the treatment of multiple sclerosis, glaucoma, nausea caused by chemotherapy and wasting caused by AIDS. However, like all drugs, it also causes numerous unwanted side effects, including hypothermia, sedation, memory impairment, motor impairment and anxiety. Research on cannabinoids could someday yield new, more effective drugs or drug combinations. At Temple University's School of Pharmacy and Center for Substance Abuse Research (CSAR), one of only a few centers in the nation focused on the basic science of substance abuse, several researchers are investigating how cannabinoids produce pharmacological effects in rats. One such study, "L-NAME, a nitric oxide synthase inhibitor, and WIN 55212-2, a cannabinoid agonist, interact to evoke synergistic hypothermia," published in the February issue of the Journal of Pharmacology and Experimental Therapeutics, reveals how cannabinoids produce one of the drug's most robust actions, hypothermia, or decreased body temperature. © 2004 Temple University, News and Media Relations.

Keyword: Drug Abuse
Link ID: 5105 - Posted: 06.24.2010

By JANE E. BRODY How sweet it is. I'm referring to the American diet, replete with sweet foods and drinks, commercially sweetened cereals, sodas, fruit drinks and "ades," ice cream, cake, muffins, cookies and candy, as well as naturally sweet fruits and fruit juices. We are all born liking a sweet taste, perhaps to stimulate a desire for breast milk, which is naturally sweet, or ripe edible fruit. These foods are excellent sources of nutrients that support growth and good health. Indeed, as the American Dietetic Association points out in a new position paper on sweeteners, "By increasing palatability of nutrient-dense foods/beverages, sweeteners can promote diet healthfulness." For example, for a child who refuses to drink milk, the addition of sweet chocolate powder can enhance consumption of this health-promoting food. Likewise, a little sugar added to a high-fiber cereal can encourage the consumption of a food that lowers cholesterol and promotes good digestion. Copyright 2004 The New York Times Company

Keyword: Obesity
Link ID: 5104 - Posted: 03.09.2004

Bar Harbor, Maine--Ears do more than hear; they also control balance and our perception of gravity and motion. An international team of scientists including David E. Bergstrom and John C. Schimenti, at The Jackson Laboratory in Bar Harbor; and Rainer Paffenholz and Gabriele Stumm at Ingenium Pharmaceuticals AG in Martinsried, Germany, identified for the first time a protein whose enzymatic function is indispensable for development of this balance system. The scientists had known that mice with the head tilt mutation known as het hear perfectly well, but carry their head at an angle and lack coordination. Mice and humans sense motion in the same way. When our heads move, a cluster of crystalline structures known as otoconia in the inner ear moves somewhat independently. This shearing motion stimulates underlying nerve endings to create the sensation of motion. The scientists found the head-tilt mice have no otoconia, but otherwise exhibit perfect inner ear formation. "Because animals use otoconia to sense their orientation in space and to monitor posture and movements, the behavior and motor coordination deficits of [the mice] can be conclusively explained by the lack of otoconia," the researchers note in the paper.

Keyword: Hearing
Link ID: 5103 - Posted: 03.09.2004

By ERICA GOODE They have been called assassins and parasites. They receive hate mail from the proponents of a variety of popular psychotherapies. The president-elect of the American Psychological Association has accused them of being overly devoted to the scientific method. But the ire of their colleagues has not prevented a small, loosely organized band of academic psychologists from rooting out and publicly debunking mental health practices that they view as faddish, unproved or in some cases potentially harmful. In journal articles and public presentations, the psychologists, from Emory, Harvard, the University of Texas and other institutions, have challenged the validity of widely used diagnostic tools like the Rorschach inkblot test. They have questioned the existence of repressed memories of child sexual abuse and of multiple personality disorder. They have attacked the wide use of labels like codependency and sexual addiction. Copyright 2004 The New York Times Company |

Keyword: Learning & Memory
Link ID: 5102 - Posted: 03.09.2004

OHSU researchers show brain anatomy, hormone production may be cause PORTLAND, Ore. – Researchers in the Oregon Health & Science University School of Medicine have confirmed that a male sheep's preference for same-sex partners has biological underpinnings. A study published in the February issue of the journal Endocrinology demonstrates that not only are certain groups of cells different between genders in a part of the sheep brain controlling sexual behavior, but brain anatomy and hormone production may determine whether adult rams prefer other rams over ewes. "This particular study, along with others, strongly suggests that sexual preference is biologically determined in animals, and possibly in humans," said the study's lead author, Charles E. Roselli, Ph.D., professor in the Department of Physiology and Pharmacology, OHSU School of Medicine. "The hope is that the study of these brain differences will provide clues to the processes involved in the development and regulation of heterosexual, as well as homosexual, behavior."

Keyword: Sexual Behavior
Link ID: 5101 - Posted: 06.24.2010

WASHINGTON, DC – Staying physically or mentally active can slow down chemical changes in the brain that lead to the neurodegeneration of Huntington’s disease, researchers show in a mouse model of the disorder. Levels of brain-derived neurotrophic factor (BDNF) stop declining when Huntington’s disease transgenic mice are housed in an enriched environment, the scientists say. BDNF promotes neuron growth and survival and can also regulate communication between neurons. “The finding that environmental enrichment increases BDNF, and that this slows disease progression, provides a potential mechanism for the effects of environmental enrichment on Huntington’s disease,” says M. Flint Beal, chair of neurology at Cornell University Medical College in New York. Copyright © 2004 Society for Neuroscience

Keyword: Huntingtons
Link ID: 5100 - Posted: 06.24.2010

Viewers who tapped out a pattern while watching a disturbing Viewers who tapped out a pattern while watching a disturbing Viewers who tapped out a pattern while watching a disturbing video suffered fewer intrusions during the following week. During the French Revolution, tricoteurs knitted away while watching hundreds lose their heads to the guillotine. Did their knitting make it less traumatic? In three experiments, University College London researchers found that viewers who performed a visuospatial task while they watched a distressing video suffered fewer intrusive memories in the following week than viewers who performed a verbal task. Spontaneously occurring intrusive memories of a traumatic event – flashbacks -- are a hallmark of posttraumatic stress disorder (PTSD). The research appears in the March issue of the Journal of Experimental Psychology: General, which is published by the American Psychological Association (APA). Participants (212 in all) viewed a 12.5-minute trauma video with five scenes of horrific content – footage of the aftermath of actual car accidents, including injured victims screaming, workers moving dead bodies, and body parts amid the wreckage. Viewers were assigned to either an experimental group (which varied by task type during viewing) or a control (no task) group. For the next seven days, they recorded any intrusive memories of the video in a diary, noting the content of each intrusion.

Keyword: Learning & Memory; Stress
Link ID: 5099 - Posted: 06.24.2010

Could muesli really boost sex drive? A muesli firm has seen a surge in sales - after its cereal was linked to claims it increased sexual prowess. Young men in Jamaica are buying the Super High Fibre muesli to mix it with milk and Guinness for an energy-boosting recipe. Now Dorset Cereals, based in Prince Charles' model village Poundbury, is gearing up to meet increased demand. The firm only found out about the story after its exporters were asked to explain the soaring sales. Business for the firm has increased by 10% on the island over the past year. Terry Crabb, Dorset Cereals' managing director, said: "We couldn't believe it when we heard the reason behind the sales increase. "Obviously the theory has spread across the island. (C)BBC

Keyword: Sexual Behavior
Link ID: 5098 - Posted: 03.07.2004

Doctors prescribing methadone for pain relief may inadvertently be the cause of an alarming rise in deaths related to the drug in the US. Forensic science experts fear that a huge increase in methadone prescriptions is feeding the black market and encouraging abuse. In 2001, the Food and Drug Administration's MedWatch programme recorded 61 methadone-related deaths in the US. That is more than occurred in the whole of the 1990s, and by 2002 the number had doubled to 123. The figures confirm reports from Maine, Florida, Oklahoma, North Carolina, West Virginia and Maryland that methadone-related deaths are rising. Methadone is often used to wean addicts off heroin, and the recent spate of deaths has led to calls for heroin-treatment programmes to be curtailed. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse; Pain & Touch
Link ID: 5097 - Posted: 06.24.2010

By JAMES DAO WASHINGTON, — High levels of lead in the city's drinking water, a problem disclosed last month, prompted several members of Congress to say on Friday that three agencies had misled residents and could have begun correcting the problem last year or even earlier. In a sometimes heated hearing on Capitol Hill, lawmakers said the agencies had failed to tell thousands of residents promptly that elevated, in some cases dangerously high, lead levels had been discovered in their houses last year. The agencies seemed disconcertingly uncertain about the problem's causes, scope and solutions, the lawmakers and expert witnesses said. "Mistakes in judgment and procedure were apparently made at every important juncture, as those involved now concede," Eleanor Holmes Norton, the delegate from the District of Columbia to Congress, said. "Any one of those three agencies could have caught the problem much earlier." Copyright 2004 The New York Times Company

Keyword: Neurotoxins; Development of the Brain
Link ID: 5096 - Posted: 06.24.2010

CHICAGO () – A study published today describes a promising new primate model for testing a potential Alzheimer's disease vaccine. This may enable scientists to study the vaccine in an animal model of Alzheimer's that is very similar to humans. The goal is to discover the cause of serious side effects that halted an earlier study of the vaccine in people, according to the Alzheimer's Association. "The animal model described in this study expands the way we might evaluate new vaccine products," said William Thies, Ph.D., Alzheimer's Association vice president for medical and scientific affairs. "Vaccination against amyloid is a reasonable strategy for preventing and possibly treating Alzheimer's and this study brings us one step closer. Having more model systems that are closer to humans increases the likelihood that we can avoid the kind of side effects that we saw in the first human trial." "Tremendous progress has been made by the National Institute on Aging, the Alzheimer's Disease Centers, universities, pharmaceutical companies and the Alzheimer's Association in understanding Alzheimer's disease. The Association's goal of delaying the disabling symptoms and eventually preventing Alzheimer's appears to be a feasible objective that the research community can achieve in the next decade," Thies added.

Keyword: Alzheimers
Link ID: 5095 - Posted: 06.24.2010

By DINITIA SMITH When David Williams, a psychologist at the University of Westminster in London, was deciding how to construct a pain machine, he realized a kitchen scale would do the trick. He attached a guillotinelike device to it, though he hastens to point out that the edge was "really blunt, not as sharp as a razor." It was designed to hit at the fingernail's half moon, where one can inflict pain without doing serious bodily harm. He was trying to figure out what influences the perception of pain. What he discovered was that both men and women were willing to take more pain from a woman than from a man. "A person's perception of pain doesn't necessarily depend on the intensity of the stimulus," Mr. Williams said in a telephone interview from his home in Stevenage, 30 miles north of London. It depends on environmental factors, like who is inflicting it. The 40 people who were tested waited longer to say "stop" when a woman was causing the pain than when a man was. Copyright 2004 The New York Times Company

Keyword: Pain & Touch
Link ID: 5094 - Posted: 03.07.2004

Scientists have come up with a theory for why time flies when you are having fun - and drags when you are bored. Scans have shown that patterns of activity in the brain change depending on how we focus on a task. Concentrating on time passing, as we do when bored, will trigger brain activity which will make it seem as though the clock is ticking more slowly. The research, by the French Laboratory of Neurobiology and Cognition, is published in the magazine Science. In the study, 12 volunteers watched an image while researchers monitored their brain activity using MRI scans. Volunteers were given a variety of tasks. In one they were told to concentrate simply on the duration of an image, in another they were asked to focus on the colour, and in a third they were asked to concentrate on both duration and colour. The results showed that a network of brain regions called the cortico-striatal loop was activated the more subjects paid attention to duration. (C) BBC

Keyword: Attention
Link ID: 5093 - Posted: 03.07.2004

Researchers say new species may be oldest ancestor Keay Davidson, Chronicle Science Writer Scientists from Berkeley, Cleveland and Japan may have finally identified the first complete species of hominids, or human ancestors, that emerged almost 6 million years ago, after the evolutionary split that led to today's chimps and humans. Key clues to its existence are six fossil teeth found in the Ethiopian desert that have forced researchers to reclassify a type of hominid previously regarded as a "subspecies," they announced in today's issue of Science. Ardipithecus kadabba is the new species' name. Besides being a separate species, Ardipithecus kadabba also may have been the first big step on the long evolutionary road from the African jungle to modern humans. ©2004 San Francisco Chronicle

Keyword: Evolution
Link ID: 5092 - Posted: 06.24.2010