It made room for larger brain, researchers theorize David Perlman, Chronicle Science Editor A tiny genetic change in the muscles of prehumans millions of years ago may have played a major role in endowing modern Homo sapiens with the larger brains and the capacity for thought, language and tool-making that distinguishes us from apes, researchers are reporting today. The novel theory, advanced by a team of biologists and surgeons, suggests that a mutation in a single gene some 2.4 million years ago was largely responsible for a crucial change in the shape of our ancestors' jaws and allowed for skulls with room for brains far larger than earlier members of the hominid line. The discovery of the gene by scientists at the University of Pennsylvania and the Children's Hospital of Philadelphia is being reported today in the journal Nature. It has already evoked surprise, excitement and also some controversy among anthropologists who study the fossil history of humanity. ©2004 San Francisco Chronicle |

Keyword: Evolution
Link ID: 5231 - Posted: 06.24.2010

By GINA KOLATA New studies in mice suggest that the hormone leptin can fundamentally change the brain's circuitry in areas that control appetite. Leptin acts during a critical period early in life, possibly influencing how much animals eat as adults. And later in life, responding to how much fat is on an animal's body, it can again alter brain circuitry that controls how much is eaten. Researchers say the findings, published today in the journal Science, are a surprise and add new clues to why weight control is so difficult in some humans. Scientists knew that leptin is released by fat cells and tells the brain how much fat is on the body. They knew that animals lacking leptin become incredibly obese, as do a few humans who because of genetic mutations did not make the hormone. Leptin injections immediately made animals, and the patients with leptin deficiencies, lose their appetites. Their weight returned to normal. Copyright 2004 The New York Times Company

Keyword: Obesity
Link ID: 5230 - Posted: 04.02.2004

The Accidental Addict Clearing away the myths surrounding the OxyContin "epidemic." By Maia Szalavitz Posted Thursday, March 25, 2004, at 11:01 AM PT In a recent five-part series (Oct. 19-23), the Orlando Sentinel painted a stark picture of the opiate drug OxyContin: Prescribed for mild pain by a clueless doctor, the drug had destroyed a former policeman's life. Apparently, this story was typical: Thousands had been derailed by the deadly drug. Within weeks, however, the drug's manufacturer, Purdue Pharmaceutical, and the ex-cop's mother-in-law revealed that the man—called an "accidental addict" by the writer, Doris Bloodsworth—was a former cocaine abuser with a federal trafficking conviction. This was not the only error the Sentinel had to account for in a 2,000-word correction: The paper had also omitted that an overdose victim profiled in the series had actually taken multiple drugs, along with OxyContin, and had previously overdosed on different medications. Even now, the Sentinel still hasn't clarified that most of the overdose deaths cited in the "investigations"— about 90 percent according to other research—were not, in fact, caused by OxyContin alone but by deadly combinations of drugs (OxyContin along with alcohol and/or other depressants like benzodiazepines). If the Orlando Sentinel were the only news organization to run massively misleading stories on OxyContin, the misinformation could be chalked up to error. But the first substantive column by the New York Times' ombudsman Daniel Okrent also dealt with OxyContin bias, albeit of a different sort—Okrent wrote that the paper shouldn't have allowed Times writer Barry Meier, author of the anti-OxyContin book Pain Killer, to cover the drug in an article in its "Science" section. Meier's article claimed that researchers now believe that "accidental" addiction is more common than previously thought—never mind the fact that there has been no new research suggesting this since OxyContin was introduced in 1995, only increased pressure from law-enforcement agents.

Keyword: Drug Abuse
Link ID: 5229 - Posted: 06.24.2010

(Philadelphia, PA) - Researchers at the University of Pennsylvania School of Medicine have found that the neurotransmitter norepinephrine is essential in retrieving certain types of memories. This represents the first description of a molecule implicated in recalling memories as opposed to laying down new memories. Teasing apart different components of this pathway may help physicians better understand post-traumatic stress disorder (PTSD) and depression -- both of which involve alterations in memory retrieval, says lead author Steven A. Thomas, MD, PhD, Assistant Professor of Pharmacology. The findings of this research appear in the April 2 issue of Cell. Using mutant mice lacking norepinephrine and rats treated with drugs that block some norepinephrine receptors (beta blockers), the research team found that this neurotransmitter is critical for retrieving intermediate-term contextual and spatial memories, but not for the formation or long-term consolidation of emotional memories, as previously hypothesized by others. Mice and rats went through learning tasks that employ different brain regions: the hippocampus, which governs spatial and contextual memories; and the amygdala, which is important for emotional learning and memory in general.

Keyword: Learning & Memory
Link ID: 5228 - Posted: 04.02.2004

ST. LOUIS, – The use of paroxetine and other antidepressant medications continues to grow by about 10% annually among children and adolescents, according to a study published in the April issue of Psychiatric Services. The study profiles trends of prescription antidepressant use in children and adolescents using prescription claim information from a random, nationwide sample. The study by Express Scripts examined antidepressant use among approximately two million commercially-insured, pediatric beneficiaries 18 years and younger from 1998 to 2002. The fastest growing segment of users were found to be preschoolers aged 0-5 years, with use among girls doubling and use among boys growing by 64%. For the entire sample, antidepressant use increased from 1.6% in 1998 to 2.4% in 2002, a 49% increase. Over the course of the study, the growth in use was greater among girls (68%) than boys (34%) and, for each gender respectively, growth was higher among younger boys and older girls.

Keyword: Depression; Development of the Brain
Link ID: 5227 - Posted: 06.24.2010

— New studies by Howard Hughes Medical Institute researchers at The Rockefeller University show that the appetite-regulating hormone leptin causes rewiring of neurons in areas of the brain that regulate feeding behavior. The discovery is another important clue about how leptin exerts its effects on the brain to cause decreased food intake and increased energy expenditure, said the researchers. The research also suggests that natural variability in the “wiring diagrams” of the neural feeding circuits of individuals may influence whether a person will be obese or lean. The research team, which was led by Howard Hughes Medical Institute investigator Jeffrey M. Friedman at Rockefeller and Tamas L. Horvath at Yale University School of Medicine, published its findings in the April 2, 2004, issue of the journal Science. Friedman and his colleagues discovered leptin in 1994. They also showed that it is produced by fat tissue and secreted into the bloodstream, where it travels to the brain and other tissues, causing fat loss and decreased appetite. In the brain, leptin affects food intake by acting on distinct classes of neurons in the hypothalamus that express the leptin receptor. ©2004 Howard Hughes Medical Institute

Keyword: Obesity
Link ID: 5226 - Posted: 06.24.2010

By RON TODT, Associated Press Writer PHILADELPHIA -- Cambridge University professor Simon Baron-Cohen thinks he knows why autism strikes four times as many boys as girls, but his theory of general differences between male and female brains has generated quite a bit of debate. Baron-Cohen theorizes that the female brain is predominantly hard-wired for empathy, and that the male brain is predominantly hard-wired for understanding and building systems -- although he is quick to note that the rule doesn't always hold true. According to his "empathizing-systemizing" theory, autism -- a neurological disorder that affects social interaction and communication -- and the possibly related Asperger syndrome are extreme male versions of the brain. "What seems to be core (to autism) is an empathy problem alongside a very strong drive to systemize," he told an audience of about 150 people Wednesday at an autism conference by the Bancroft Neuroscience Institute. Copyright © Newsday, Inc.

Keyword: Autism
Link ID: 5225 - Posted: 06.24.2010

Men who smoke cannabis could be damaging their fertility, research carried out by Queen's University Belfast has suggested. The study by the university's Reproductive Medicine Research Group examined the direct effects on sperm function of THC, the active ingredient in cannabis. The group found that THC made sperm less likely to reach the egg to fertilise it. They also discovered that the presence of cannabis impaired another crucial function of sperm - the ability to digest the egg's protective coat with enzymes to aid its penetration. The government reclassified cannabis to a class C drug in January, putting it on a par with tranquilisers. Dr Sheena Lewis, from the university's Department of Obstetrics and Gynaecology, said on Wednesday that the recent reclassification of cannabis made research on its effects more important. "The need to determine its effects on male fertility is even greater, so that men can make an informed choice about smoking the drug based on its risks to their health," she said. (C)BBC

Keyword: Dyslexia
Link ID: 5224 - Posted: 04.01.2004

Analysis Yields New Insights into Medical Model, Evolutionary Process Bethesda, Maryland — An international research team, supported by the National Institutes of Health (NIH), today announced it has completed a high-quality, draft sequence of the genome of the laboratory rat, and has used that data to explore how the rat's genetic blueprint stacks up against those of mice and humans. In a paper published in the April 1 issue of the journal Nature, the Rat Genome Sequencing Project Consortium describes its efforts to produce and analyze a draft sequence of the Brown Norway strain of the laboratory rat (Rattus norvegicus). The project, led by the Human Genome Sequencing Center at Baylor College of Medicine in Houston, was primarily funded by the National Heart, Lung and Blood Institute (NHLBI), $58.5 million, and the National Human Genome Research Institute (NHGRI), $60 million. "This is an investment that is destined to yield major payoffs in the fight against human disease," said NIH Director Elias A. Zerhouni, M.D. "For nearly 200 years, the laboratory rat has played a valuable role in efforts to understand human biology and to develop new and better drugs. Now, armed with this sequencing data, a new generation of researchers will be able to greatly improve the utility of rat models and thereby improve human health."

Keyword: Genes & Behavior
Link ID: 5223 - Posted: 06.24.2010

The use of photographs by psychotherapists as memory cues for the "recovery" of patients' possible childhood sexual abuse has been called into question by a Canadian study. It found that a "staggering" two-out-of-three participants accepted a concocted false grade-school event as having really happened to them when suggestions regarding the event were supplemented with a class photo. "I was flabbergasted to have attained such an exceptionally high rate of quite elaborate false memory reports," says University of Victoria psychology professor Dr. Stephen Lindsay. His NSERC-sponsored research is published in the March 2004 issue of Psychological Science. Forty-five first year psychology students were told three stories about their grade-school experiences and asked about their memories of them. Two of the accounts were of real grade three to six events recounted to the researchers by the participant's parents. The third event was fictitious, but also attributed to the parents. It related how, in grade one, the subject and a friend got into trouble for putting Slime (a colourful gelatinous goo-like toy made by Mattel that came in a garbage can) in their teacher's desk. The participants were encouraged to recall the events through a mix of guided imagery and "mental context re-instatement"--the mental equivalent of putting themselves back in their grade-school shoes. Half of the participants were also given their real grade one class photo, supplied by their parents.

Keyword: Learning & Memory
Link ID: 5222 - Posted: 04.01.2004

Researchers at Mount Sinai School of Medicine are first to strongly link a specific gene with autism. While earlier studies have found rare genetic mutations in single families, a study published in the April issue of the American Journal of Psychiatry is the first to identify a gene that increases susceptibility to autism in a broad population. Approximately 1 in 1,000 people have autism or autistic disorder. It appears to be the most highly genetic of all psychiatric disorders. If a family with one autistic child has another child the chance that this child would be autistic is 50 to 100 times more likely to than would be expected by chance. However, it's clear that no single gene produces the disorder. Rather, the commonly accepted model states that it is a result of the accumulation of between five to ten genetic mutations. "Identifying all or most of the genes involved will lead to new diagnostic tools and new approaches to treatment," said Joseph Buxbaum, PhD, Associate Professor of Psychiatry, Mount Sinai School of Medicine and lead author of the study.

Keyword: Autism; Genes & Behavior
Link ID: 5221 - Posted: 04.01.2004

By ROWAN HOOPER Things are never what they seem. Men certainly aren't, according to the American writer Marilyn French: "Whatever they may be in public life, whatever their relations with men, in their relations with women, all men are rapists, and that's all they are." French said that in 1977. It wasn't good PR for the feminist movement. Maybe some feminists did, as detractors claimed, have something against men -- but it was nothing compared to what a group called Wolbachia have against them. Wolbachia are male-killers, though sometimes they only castrate males. Yet they are not radical feminist guerrillas: They are bacteria. Wolbachia quietly infect at least a million species of insects, spiders and crustaceans, and for males with a dose, the outcome is bleak. Wolbachia are obligate symbionts, which means they can only live in the cells of a host animal. But they don't like males. In some species the bacteria kill the male outright (no males mean more resources for females), while in others Wolbachia hijack the male's reproductive apparatus and makes it female. In some insects Wolbachia cause parthenogenesis (egg development without sperm fertilization) and thus do away with the need for males altogether. The Japan Times (C) All rights reserved

Keyword: Sexual Behavior; Evolution
Link ID: 5220 - Posted: 03.31.2004

By TRACEY HARDEN WHY did Seattle's Woodland Park Zoo design its jaguar habitat so the big cats can creep into tree branches and lurk over the heads of visitors? For one thing, it is the kind of activity that jaguars enjoy. For another, getting that kind of thrill — at a safe distance — is something zoo visitors like. Call the exhibit an exemplar of "ecological psychology," a term used by zoo directors and planners to explain the increased focus not only on animal comfort but also on the needs of humans and the ways they interact with animals. "We're providing behavioral enrichment for our visitors as well as animals," said John Bierlein, the zoo's manager of planning and interpretive exhibits. "We recognize that most people have grown up in urban areas and we want to reconnect them with the natural world." Copyright 2004 The New York Times Company

Keyword: Animal Rights
Link ID: 5219 - Posted: 06.24.2010

By Jennifer Viegas, Discovery News — In late April, Chinese archivists will unveil a rare collection of items featuring Nushu, a mysterious ancient language created by, and exclusively for, women. The exhibition, to be held at the provincial archive of Guangxi Zhuang Autonomous Region in southern China, appears to be part of a growing effort within China to both recognize and preserve Nushu, which many scholars feared was on the verge of extinction. Nushu, meaning women's script, was held so securely by its speakers and writers that women used to burn manuscripts to keep them away from men, or they would bury items containing Nushu with female friends upon their deaths. The language's origins are unclear, but most scholars believe Nushu emerged in the third century during a time when the Chinese government prohibited education of women. Practices such as arranged marriages and foot binding also prevented many women from travelling far beyond their homelands. Copyright © 2004 Discovery Communications Inc.

Keyword: Language
Link ID: 5218 - Posted: 06.24.2010

DURHAM, N.C. -- A drug commonly prescribed to halt pre-term labor and stave off premature birth might leave the brains of children susceptible to other chemicals ubiquitously present in the environment, according to research conducted on laboratory animals by Duke University Medical Center pharmacologists. Their new study found that rats exposed to the pre-term labor drug terbutaline suffer greater brain cell damage than those not given the drug upon secondary exposure to the insecticide chlorpyrifos. The double exposure caused damage to brain regions known to play a role in learning and memory, the team reported in the March 2004 issue of Toxicology and Applied Pharmacology. The result might therefore help to explain earlier suggestions that children whose mothers are administered terbutaline suffer cognitive deficits. The National Institutes of Health supported the research. Premature labor occurs in approximately 20 percent of all pregnancies in the United States. Of those, an estimated 1 million women annually are treated with terbutaline or related drugs to halt the early contractions. The drugs administered to pregnant women also penetrate to the fetus where they affect brain development. © 2001-2004 Duke University Medical Center.

Keyword: Development of the Brain
Link ID: 5217 - Posted: 06.24.2010

A woman's face is most alluring at the height of her cycle. DAVID KRAMER Women who make the room light up with their good looks may have a secret up their sleeve - it may be down to their menstrual cycle. Both men and women consider a woman's face to be at its most attractive when she is at the peak of her fertility, according to new research. Craig Roberts from the University of Newcastle and colleagues looked at how female facial attractiveness varies during their menstrual cycle, to see if that might convey the level of their fertility. Other animals have more obvious ways of letting their mates know when they are fertile: for example, female chimps' genital areas swell and turn pink. Roberts and his team selected about 50 women aged between 19 and 33 years in both Newcastle and Prague, the hometowns of two of the group members. They took two pictures of each subject. The first picture showed them when they were fertile, 8 to 14 days after the first day of their last menstruation. The second was taken 14 days later. © Nature News Service / Macmillan Magazines Ltd 2004

Keyword: Sexual Behavior
Link ID: 5216 - Posted: 06.24.2010

Suggests people choose canines who resemble themselves Long the subject of speculation, a new study says that dogs DO resemble their owners. At least this is the case with purebred canines, according to new research conducted at the University of California, San Diego, by social psychologist Nicholas Christenfeld and his UCSD colleague, Michael Roy. The full study, Do Dogs Resemble Their Owners?, appears in the May issue of Psychological Science, the journal of the American Psychological Society that focuses on empirical research in psychology. The UCSD psychologists found that when people pick a dog, "they seek one that, at some level, resembles them, and, when they get a purebred, they get what they want." Forty-five dogs and their owners were separately photographed and judges were shown pictures of an owner, that owner's dog, and one other dog, with the task of picking out the true match. The proof of resemblance was that a majority of the purebred dogs and their owners could be identified by the 28 judges called upon to examine the photographs, with the results showing 16 matches out of the 25 purebreds. There was no evidence of resemblance between the mixed breed dogs and their owners.

Keyword: Miscellaneous
Link ID: 5215 - Posted: 03.31.2004

UCLA scientists report parallels between human speech and the song of a bird, findings that may contain clues to human speech disorders. The research by a team led by Stephanie White, UCLA assistant professor of physiological science, supports the theory that two genes shared by humans and songbirds, FoxP1 and FoxP2, may play a critical role in human speech, and speech disorders. The study is published March 31 in the Journal of Neuroscience. "We examined the expression of FoxP1 and FoxP2 in embryonic human brains and found a striking correspondence between bird and human expression," said White, a member of UCLA's Brain Research Institute. "The similar expression patterns suggest that songbirds can be studied to investigate neural mechanisms for vocal learning that may be parallel to those used by the human brain. "Our findings make it more likely that FoxP2 plays a critical role for learning speech and vocalization in both humans and the songbird," she said. "Understanding how FoxP1 and FoxP2 function in the songbird may reveal significant insights into human vocal learning and speech disorders."

Keyword: Language; Genes & Behavior
Link ID: 5214 - Posted: 06.24.2010

A drug once used to treat stomach ulcers may help to boost brainpower in old age, a study suggests. Researchers at the University of Edinburgh carried out tests on 22 men between the ages of 52 and 75. Some of the men were given a drug called carbenoxolone and others were given a dummy drug. Writing in the Proceedings of National Academy of Sciences, they said those on carbenoxolone had better memory and verbal skills after just six weeks. Carbenoxolone is derived from liquorice root. It used to be prescribed by doctors to treat stomach ulcers. However, it has since been replaced by more effective drugs. The drug is known to block a chemical called 11 beta-hydroxysteroid dehydrogenase type 1. (C) BBC

Keyword: Alzheimers
Link ID: 5213 - Posted: 03.30.2004

By DAVID TULLER That teenagers are often so sleep-deprived they can barely crawl out of bed in the morning is not news. But researchers have found that these days, even many babies no longer sleep like a baby. Infants average almost 90 minutes less sleep a day than the 14-hour minimum doctors recommend, according to a survey of more than 1,400 parents and others who care for children 10 and younger. The results are being released today. The poll, by the National Sleep Foundation, an organization that promotes education and research on sleep, also found that toddlers get on average at least two hours a week less and preschoolers more than four hours less than the minimum amount they need to function at their best. Sleep experts recommend 12 to 14 hours a day for children 12 to 35 months old and 11 to 13 hours for preschoolers. Copyright 2004 The New York Times Company

Keyword: Sleep
Link ID: 5212 - Posted: 03.30.2004