-- In the current issue of the Journal of Neuroscience, Johns Hopkins researchers report that injection of human stem cells into the fluid around the spinal cord of each of 15 paralyzed rats clearly improved the animals' ability to control their hind limbs -- but not at all in the way the scientists had expected. "Our first hypothesis was that functional recovery came from human cells reconstituting the nerve circuits destroyed by the paralysis-inducing virus we gave the rats," says first author Douglas Kerr, M.D., Ph.D., assistant professor of neurology at the Johns Hopkins School of Medicine. "Some of the tens of thousands of implanted primitive human stem cells did become nerve cells or the like, but not enough to account for the physical improvements. "Instead, these human embryonic germ cells create an environment that protects and helps existing rat neurons -- teetering on the brink of death -- to survive," he says. Copyright © 1992-2003 Bio Online, Inc.

Keyword: Stem Cells; Regeneration
Link ID: 3968 - Posted: 06.24.2010

Humans may have evolved a language skill from primate ancestors. HELEN R. PILCHER Rhesus monkeys can match up sounds and facial expressions, research suggests1. It hints that our capacity to do likewise may have evolved from our primate ancestors. "Some people had thought that the ability was unique to humans," says Asif Ghazanfar of the Max Planck Institute for Biological Cybernetics, Germany, who studied the monkeys. Other animals had simply not been tested. In captivity and the wild, rhesus monkeys (Macaca mulatta) produce a variety of noises. "Almost all have a unique facial expression," says Ghazanfar. © Nature News Service / Macmillan Magazines Ltd 2003

Keyword: Emotions; Language
Link ID: 3967 - Posted: 06.24.2010

Author Chris McManus wins £10,000 Aventis award for exploration of asymmetry. PHILIP BALL This year's winner of the world's most prestigious science book competition was announced in London last night. Psychologist Chris McManus was awarded the £10,000 Aventis Prize for his work Right Hand, Left Hand: The Origins of Asymmetry in Brains, Bodies, Atoms and Cultures. A panel chaired by British novelist Margaret Drabble picked Right Hand, Left Hand, published by Weidenfeld & Nicolson, from a shortlist of six entries on topics ranging from cosmology to risk perception. In it, McManus who works at University College in London, explores the phenomenon of handedness from the human to the subatomic level. He discusses why we are predominantly right-handed, why there is an imbalance in other animals too - parrots are southpaws, he reveals - and why amino acids, the building blocks of proteins and DNA exist in mirror image forms. © Nature News Service / Macmillan Magazines Ltd 2003

Keyword: Laterality
Link ID: 3966 - Posted: 06.24.2010

Tampa, FL -- The buildup of Alzheimer's-associated amyloid plaques in the brain dramatically inhibits several genes critical to memory and learning, University of South Florida College of Medicine researchers have found. The strong link between the decreases in select memory genes and amyloid accumulation was observed both in mice genetically engineered to develop memory loss and in the brains of deceased Alzheimer's patients. The results are reported in the June 15 issue of the Journal of Neuroscience published online today. "Blocking the ability of amyloid to inhibit, or down-regulate, these genes may improve memory in patients with early Alzheimer's disease," said principal investigator David Morgan, PhD, professor of pharmacology and therapeutics and director of the Alzheimer's Disease Research Laboratory at USF.

Keyword: Alzheimers; Learning & Memory
Link ID: 3965 - Posted: 06.30.2003

Madrid, Spain: Researchers have found the first evidence that a common cause of infertility in women is more prevalent amongst lesbians than heterosexuals[1], and they suggest that the biochemical disorder associated with the condition might contribute to the women's sexual orientation. Polycystic ovarian syndrome (PCOS) is the commonest cause of ovarian dysfunction in women and is caused by an imbalance of sex hormones. One of the main features of PCOS is hyperandrogenism[2], and now that the researchers have discovered the increased prevalence of PCOS amongst lesbian women they hypothesize that hyperandrogenism could be contributing to the women's sexual orientation. Dr. Rina Agrawal, deputy medical director at the London Women's Clinic and The Hallam Medical Centre, and her colleagues examined 618 women who attended the clinic for fertility treatment between November 2001 and January 2003. Of these, 254 were lesbian and 364 were heterosexual women.

Keyword: Sexual Behavior
Link ID: 3964 - Posted: 06.30.2003

Neurogenesis in the central nervous system can be the start of something huge By Ricki Lewis The brain and spinal cord were once considered mitotic dead ends, a division of neurons dwindling with toddlerhood, with memory and learning the consequence of synaptic plasticity, not new neurons. But the discovery of neural stem cells (NSCs) in the human adult central nervous system (CNS) has raised the possibility of reawakening neurogenesis in the adult to treat neurodegenerative diseases, such as Parkinson, Alzheimer, and Huntington diseases, and spinal cord injuries. "Does the human CNS self-repair? Of course it does! We live 90 years. It is unreasonable to think that there is no turnover, like in every other organ," says Fred Gage, of Salk Institute for Biological Studies, La Jolla, Calif., who led the team that discovered neural stem cells in the human brain in 1998. "Can we turn endogenous cells into neurons in a disease setting? Can we activate our own systems? We are beginning to unravel cell fates and choices, to distinguish intrinsic properties of cells versus local environment cues. For cells, it is not who you are, but where you are, that counts." ©2003, The Scientist Inc.

Keyword: Neurogenesis; Regeneration
Link ID: 3963 - Posted: 06.24.2010

An analysis of research studies with long-term, recreational users of marijuana has failed to reveal a substantial, systematic effect on the neurocognitive functioning of users. According to researchers at the University of California, San Diego (UCSD) School of Medicine, the only deleterious side effect found was a minimal malfunction in the domains of learning and forgetting. The findings were particularly significant considering the movement by several states to make cannabis (marijuana) available as a medicinal drug, and questions regarding its potential toxicity over long-term usage. Published in the July issue of the Journal of the International Neuropsychological Society, the study involved a quantitative synthesis of 15 previously published research studies on the non-acute (residual) effects of cannabis on the neurocognitive performance of adult human subjects.

Keyword: Drug Abuse
Link ID: 3962 - Posted: 06.30.2003

We all have a little stress in our lives. But after studying nerve cells in a banana-shaped area of the brain called the hippocampus, a hub for learning and memory, neuroscientists say chronic stress can have devastating effects on our brains. Bruce McEwen, professor and head of the neuroendocrinology laboratory at the Rockefeller University, explains more about the hippocampus: “It’s a structure that is very important for remembering where you were and what you were doing when something important happened; in other words, providing context. For example, remembering where we were and what we were doing on September 11, 2001—that’s a function of the hippocampus. The reason that we remember that horrible day is that another brain structure very close to the hippocampus, called the amygdala, is a structure that reacts strongly to emotionally-charged events, either very positive or very negative events.” McEwen and his team, who published their research in the February, 2003 issue of Nature Neuroscience, looked at the brain cells of both stressed and not-so-stressed mice, and found something interesting about the brains of stressed-out mice. “[Nerve cells] have these wonderful trees [with branches] that are called dendrites, places where other nerve cells make connections and transmit chemical signals,” says McEwen. These cells connect to each other at junctions called synapses. “When we look at these individual nerve cells from an animal that’s stressed or not stressed, we could see some very characteristic changes. For example, the branches become shorter and less branched, as a result of repeated stress. That means there are fewer synaptic connections, and it means these cells are not receiving as much information as they normally do. When you look at many of these cells you realize that many of the cells in this brain area called the hippocampus show this shrinkage after repeated stress.” © ScienCentral, 2000-2003.

Keyword: Stress
Link ID: 3961 - Posted: 06.24.2010

By MARY DUENWALD Did you know that it's Beautiful Women Month?" a frequently forwarded e-mail message asks, before making a few pertinent statements. Here's a sampling: "Marilyn Monroe wore a size 14"; "If Barbie was a real woman, she'd have to walk on all fours"; and "The average woman weighs 144 lb. and wears between a 12-14." There are more "facts on figures," not all of them are perfectly accurate. Ms. Monroe, who was 5 feet 5 1/2 inches and weighed between 118 to 135 pounds, may have been just busty enough to fill out a size 14, but partly because sizes were smaller in the 1950's. And Barbie is indeed disproportionate — a 1995 study found that for a woman with an average body type to attain Barbie's shape, she would need to grow 24 inches (making her more than 7 feet tall), take 6 inches off her waist and add 5 to her chest. But if she came to life, she could presumably still walk upright, the director of the study said. As for the average woman's weight today, it has jumped to 152 pounds in the 90's from 144 in the late 70's.

Keyword: Anorexia & Bulimia
Link ID: 3960 - Posted: 06.24.2010

Males self-destruct to keep their mates faithful. JOHN WHITFIELD The male orb-weaving spider self-destructs during mating. By dying while still joined to a female, his corpse forms a kind of chastity belt, say ecologists. Male spiders have two sex organs, called palps, which they insert into the female one after another. When the spider Argiope aurantia uses his second palp he suffers an irreversible seizure, say Matthias Foellmer and Daphne Fairbairn of the University of California, Riverside. "Immediately after, he becomes motionless," says Foellmer. "Males show the typical dead posture, with legs folded under the body. Their hearts stop within 15 minutes." © Nature News Service / Macmillan Magazines Ltd 2003

Keyword: Sexual Behavior
Link ID: 3959 - Posted: 06.24.2010

By NATALIE ANGIER Hail America, land of the speedy and home of the shaved, where the list of short things we love keeps getting longer. We love brief wars and abbreviated weapons, instant messaging and prescient gratification. A duchess said you can't be too trim; editors say the same about stories. But the one thing we don't like short and never have is our men. There is a harsh rule of thumb about male height, and it measures six feet and counting. As study after study has shown, tall men give nearly all the orders, win most elections, monopolize girls and monopolies, and disproportionately splay their elongated limbs across the cushy unconfines of first-class cabins. By the simple act of striding into a room, taller than average men are accorded a host of positive attributes having little or nothing to do with height: a high IQ, talent, competence, trustworthiness, even kindness. And men who are considerably shorter than the average American guy height of 5-foot-9 1/2? These poor little fellows are at elevated risk of dropping out of school, drinking heavily, dating sparsely, getting sick or depressed. They have a lower chance of marrying or fathering children than do taller men, and their salaries tend to be as modest as their stature. If they are out striving to make their mark, they are derided as "Little Napoleons." Call them whatever you please, and chances are you won't get called on it, for making fun of short men is one of the last acceptable prejudices. Copyright 2003 The New York Times Company

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 3958 - Posted: 06.24.2003

Nature, Nurture, and Early Brain Development It’s no surprise that children pick up many of the habits and behaviors from their parents. But as this ScienCentral News video reports, scientists may be getting closer to knowing why many traits get passed on from one generation to the next. Physical characteristics are easy to trace—we look like our parents because we inherit their genes. But what about qualities we can’t see, like personality traits? Do we inherit the way we handle stress? “Highly anxious mothers have been found to have offspring who inherit some of these anxious traits [like a] higher risk for depression and other problems,” says Frances Champagne, a doctoral student in neurology and neurosurgery at McGill University. By the same token, children of less stressed-out mothers grow up to be less anxious. But is this nature, something that’s passed on in our genes? Or is it nurture, something shaped by our environment? Researchers say it’s both—you have to have the gene first, and then the environment. © ScienCentral, 2000-2003.

Keyword: Development of the Brain
Link ID: 3957 - Posted: 06.24.2010

NewScientist.com news service Doctors and nurses have known for many years that some people are more sensitive to pain than others. Now brain scans of people experiencing the same painful stimulus have provided the first proof that this is so. But the scans also suggest that how much something hurts really is "all in the mind". "We saw a huge variation between responses to the same stimulus," says project leader Bob Coghill of the Wake Forest University School of Medicine in Winston-Salem, North Carolina. "The message is: trust what patients are telling you." Coghill tested the pain tolerance of 17 healthy volunteers by applying heat to the back of their calves. He varied the heat from around body temperature to 49 °C, the temperature of very hot washing-up water. © Copyright Reed Business Information Ltd.

Keyword: Pain & Touch
Link ID: 3956 - Posted: 06.24.2010

Active brain may delay Alzheimer's, doctors say Ulysses Torassa, Chronicle Health Writer As a child growing up in the East Bay, Wyman Hicks had an IQ of 185. After serving in World War II, he directed a major part of the rebuilding of war-torn Japan under Gen. Douglas MacArthur. As a businessman, he led research and development for the Crown Zellerbach Corp., where he came up with the idea of putting handles on paper grocery bags. Hicks later taught management at Sonoma State University and, after retiring, represented Sen. Barbara Boxer, D-Calif., at events in and around Marin County. He's already written his memoirs up through his business career and is piecing together a second installment that will take him up to the present. It's no easy task, especially for someone like Hicks, who has Alzheimer's disease. But while tests show that the 85-year-old Fairfax resident has reduced mental functioning, he isn't the typical Alzheimer's patient, doctors say. In person, he demonstrates a remarkable vocabulary and recall. And although his physician notified the Department of Motor Vehicles of his diagnosis, he had no trouble passing both the written and driving test to keep his license. ©2003 San Francisco Chronicle

Keyword: Alzheimers
Link ID: 3955 - Posted: 06.24.2010

By JOHN O'NEIL A new study from Yale suggests that drug addiction should be thought of as a developmental disorder, because the changing circuitry of teenagers' brains appears to leave them especially vulnerable to the effects of drugs and alcohol. Dr. R. Andrew Chambers of the Yale School of Medicine, lead author of the article, said addictive drugs worked by stimulating parts of the brain that are changing rapidly in adolescence. In particular, Dr. Chambers said, the drugs tap into a neural imbalance that may underlie teenagers' affinity for impulsive and risky behavior. The circuitry that releases chemicals that associate novel experiences with the motivation to repeat them develops far more quickly in adolescence than the mechanisms that inhibit urges and impulses. Copyright 2003 The New York Times Company

Keyword: Drug Abuse; Development of the Brain
Link ID: 3954 - Posted: 06.24.2003

Insulin, the hormone that escorts fuel into cells, keeps the brain functioning properly. But a growing body of evidence suggests that too much insulin could foster the buildup of [name] -amyloid, a peptide that contributes to Alzheimer's disease. A new study is the first to illuminate that link in elderly people. Insulin can improve short-term memory function, in addition to the hormone's other duties such as regulating blood sugar levels. But high levels of insulin can be too much of a good thing, neuroscientists have found in tests on animals and cells (ScienceNOW, 19 November 2001 ). An enzyme called insulin-degrading enzyme (IDE) clears both insulin and [name] -amyloid. Excess insulin might divert the enzyme from its dual responsibilities, allowing [name] -amyloid to build up and eventually clump into plaques in the brain--a key development in Alzheimer's disease. Copyright © 2003 by the American Association for the Advancement of Science.

Keyword: Alzheimers
Link ID: 3953 - Posted: 06.24.2010

It's been something of a mystery to scientists - how are blind mice able to synchronize their biological rhythms to day and night? New research by a team of scientists, including one from the University of Toronto, seems to have uncovered the answer. Rods and cones in the outer retina are the eyes' main photoreceptors, explains Nicholas Mrosovsky, professor emeritus in zoology at U of T. When these rods and cones degenerate, mammals and animals become blind. Despite this, however, some animals can synchronize their biological clocks to the day/night cycle, a problem that has perplexed scientists for the past decade. "We believed there must be some other specialized receptor for detecting night and day. We now have evidence that this long sought-after photoreceptor is a layer of cells, located in the inner retina, that contain melanopsin, a pigment chemically related to other opsins [a type of protein] found in the rods and cones of the outer retina."

Keyword: Biological Rhythms; Vision
Link ID: 3952 - Posted: 06.24.2003

The more education, the better memory and learning ability Researchers at Rush-Presbyterian-St. Luke's Medical Center in Chicago have found that the more formal education a person has, the better his or her memory and learning ability, even in the presence of brain abnormalities characteristic of Alzheimer's disease (AD). New findings from the Religious Orders Study (ROS), a long-running prospective study of aging and cognitive function in Catholic clergy, offers important new evidence that formal education may provide a cognitive "reserve" or a "neuroplasticity" that can reduce the effect of AD brain abnormalities on cognitive function in later life. The research, published in the June 24, 2003, issue of Neurology by Dr. David A. Bennett, Rush colleagues and researchers at the University of Pennsylvania, examined physical characteristics of autopsied brains of deceased participants in the Religious Orders Study. Bennett and colleagues also looked at the participants' years of education and performance on tests of overall cognitive function before death. Each of the 130 participants underwent cognitive testing about 8 months before death. In those tests, 19 measures of cognitive function were used to create a global cognitive function measure involving different forms of memory, perceptual speed, and "visuospatial" ability.

Keyword: Alzheimers; Learning & Memory
Link ID: 3951 - Posted: 06.24.2003

Grabbing an hour's sleep during the day may be as beneficial as a whole night in bed, according to scientists. But the "power-nap" only works if the sleep is of the right quality, say the experts from Harvard University. However, experts say that a full night's sleep is still necessary for many vital body functions, even though a short sleep may boost learning and memory. Many famous people have claimed that it is possible to get by on just a few hour's sleep a night. Yachtswoman Ellen MacArthur sailed solo around the world while sleeping only occasionally and for very short periods. However, there are plenty of others who say they cannot function properly without a full night's sleep. (C) BBC

Keyword: Sleep; Learning & Memory
Link ID: 3950 - Posted: 06.23.2003

By PETER D. KRAMER Patients are beginning to treat depression with respect. Whether their doctors are ready to do so is less clear. A study in the current issue of The Journal of the American Medical Association finds that almost six in 10 Americans who suffer depression seek treatment in a given year. A decade ago, the figure was one in three. But the researchers found that only about 40 percent of patients received what standard guidelines consider "minimally adequate medical treatment." Those criteria call for a month of antidepressants monitored in four office visits or eight half-hour counseling sessions. Copyright 2003 The New York Times Company

Keyword: Depression
Link ID: 3949 - Posted: 06.23.2003