A ubiquitous signaling molecule, nitric oxide (NO), turns off the production of new neurons in the adult brain, researchers have discovered. By shutting down this off switch, doctors may one day be able to generate new neurons in the brains of patients suffering from neurological diseases or traumatic injury. Most neurons in the human brain are born while the fetus is still tucked inside its mother's womb. But in recent years, researchers have discovered that adult brains have stem cells that develop into brand-new nerve cells later in life. Doctors are tantalized by this because many ailments associated with aging, such as Parkinson's or Alzheimer's disease, are caused by degeneration of neurons in the brain. If doctors could stimulate neuron development at will, it might be possible to slow or even reverse the damage caused by such diseases. Until now, however, researchers have made little progress in understanding what turns on adult neuron development. So New York neuroscientists Grigori Enikolopov of the Cold Spring Harbor Laboratory and Steven Goldman of Cornell University decided to look instead for the off switch. They focused on an enzyme called neuronal nitric oxide synthase (nNOS), suspected to put the brakes on cell proliferation by producing NO. Using rats, the team injected a nNOS inhibitor into areas of the brain where new stem cells are known to divide. To their surprise, the number of stem cells that developed into neurons increased by 70%. "It was like we released the parking brake," said Enikolopov. A neuron-specific dye proved that the new stem cells had indeed become neurons. Copyright © 2003 by the American Association for the Advancement of Science.

Keyword: Neurogenesis
Link ID: 4108 - Posted: 06.24.2010

By TINA HESMAN Post-Dispatch New research by neuroscientists at Washington University suggests that anti-depressant drugs may have additional benefits beyond helping patients feel better now. In a study published today in the American Journal of Psychiatry, Dr. Yvette I. Sheline and her colleagues found that women who had taken drugs to fight depression had less shrinkage in a region of the brain known as the hippocampus than women whose depression was left untreated. The hippocampus is a part of the brain involved in learning and memory. People with smaller hippocampus volumes tend to perform poorly on verbal memory tests, Sheline said. And depression has been linked to an increased risk of Alzheimer's disease. Anti-depressant drugs may help stave off those complications by keeping the hippocampus pumped up. St. Louis Post-Dispatch COPYRIGHT 2003

Keyword: Depression
Link ID: 4107 - Posted: 08.02.2003

New Study Sharpens Debate on Men, Sex and Gender Roles By Shankar Vedantam Washington Post Staff Writer A fierce debate about whether jealousy, lust and sexual attraction are hardwired in the brain or are the products of culture and upbringing has recently been ignited by the growing influence of a school of psychology that sees the hidden hand of evolution in everyday life. Fresh sparks flew last month when a study of more than 16,000 people from every inhabited continent found that men everywhere -- whether single, married or gay -- want more sexual partners than women do. "This study provides the largest and most comprehensive test yet conducted on whether the sexes differ in the desire for sexual variety," wrote lead researcher David P. Schmitt, an evolutionary psychologist at Bradley University in Peoria, Ill. "The results are strong and conclusive -- the sexes differ, and these differences appear to be universal." © 2003 The Washington Post Company

Keyword: Sexual Behavior; Evolution
Link ID: 4106 - Posted: 06.24.2010

Sylvia Pagán Westphal Breathing problems are to blame for many cases of bed-wetting in children, and perhaps even in some adults too. And a simple treatment might solve the problem within weeks. That, at least, is the claim of a few researchers. If you find it implausible, you are not the only one. "When I speak to professionals, they shake their heads in disbelief," says Derek Mahony, an orthodontist in Sydney, Australia, who is about to start a trial of a potential treatment. Very few doctors and parents are even aware there may be a link, he says. Much of the evidence comes from follow-up studies of children who have enlarged adenoids or tonsils removed. For instance, a 2001 study of 321 children found that over a third of them wet their beds prior to surgery. Of these, 63 per cent stopped completely three months after surgery (International Journal of Pediatric Otorhinolaryngology, vol 59, p 115). Other studies have produced similar results. © Copyright Reed Business Information Ltd.

Keyword: Sleep
Link ID: 4105 - Posted: 06.24.2010

By DAVID TULLER They are called smart pills or brain boosters or, to use the preferred pharmaceutical term, cognitive enhancers. But whatever the name given to compounds created to prevent or treat memory loss, drug companies and supplement producers — eager to meet the demands of a rapidly growing market — are scrambling to exploit what they view as an enormous medical and economic opportunity. Three drugs being prescribed for Alzheimer's disease — donepezil (Aricept), galantamine (Reminyl) and rivastigmine (Exelon ) — have been shown to delay somewhat the loss of mental abilities in people with the illness. So has the drug memantine, which has been used for years in Europe but has not been approved in the United States. Some experts also say that performing mental exercises and adding fish oil to the diet can delay memory decline. Copyright 2003 The New York Times Company

Keyword: Alzheimers; Learning & Memory
Link ID: 4104 - Posted: 06.24.2010

Age-dependent learning deficit can be overcome by the reduced production of a potassium channel in the mouse model All of us experience a successive decline in learning and memory capacities with ageing. In the course of their investigations of the neurophysiological basis of this decline, Thomas Blank, Ingrid Nijholt, Min-Jeong Kye, Jelena Radulovic, and Joachim Spiess from the Max Planck Institute for Experimental Medicine in Göttingen have obtained new insight into the mechanisms of age-related learning deficits in the mouse model. In experiments with mice, the Max Planck researchers were able to revert the observed age-related learning and memory deficits by down-regulation of calcium-activated potassium channels (SK3) located in the hippocampus, a brain region recognized to be important for learning and memory. The researchers published their results as a Brief Communication in the journal Nature Neuroscience. In the study, young (4-6 months) and aged mice (22-24 months) had to learn that a defined tone was associated with a mild electric footshock serving as an aversive stimulus. If the tone was immediately followed by a footshock, young and aged mice remembered easily the association on the following day. They showed their memory by a so-called "freezing response" when exposed to the same tone used for training, but without application of a foot shock. This freezing, a naturally occurring defense behavior, is characterized by complete immobility of the mouse. The scientists then generated a more complex learning task by separating the tone from the shock by several seconds. As result of this change, the task now required specifically the hippocampus. Under these conditions, the aged mice were strongly impaired in comparison to the young mice. In agreement with the behavioral differences between aged and young mice, the scientists observed that "long-term potentiation" (LTP), an electrophysiological phenomenon indicating neuronal plasticity was lower in hippocampal brain tissue of aged mice when compared to LTP in hippocampus of young mice.

Keyword: Intelligence; Alzheimers
Link ID: 4103 - Posted: 06.24.2010

Rodent 'g' might reveal genes for intellect. HELEN PEARSON Some mice are cleverer than others, say US neuroscientists. Their rodent equivalent of an IQ test might fuel the controversial pursuit for genes linked to human intelligence. Scientists have long used a factor called general intelligence or 'g' to rate people's brainpower. The measure spans verbal, logical and mathematical tasks - so a person with a big 'g' tends to score highly in all intelligence quotient (IQ) tests, and do well in school and work. Mice have a version of 'g', according to a team led by Louis Matzel of Rutgers University in Piscataway, New Jersey1. Animals that come top in one learning test often score better on others, they found: a maze champion might be a sniffing sensation too. "Once in a while you come across one that's absolutely stunning," says Matzel. © Nature News Service / Macmillan Magazines Ltd 2003

Keyword: Intelligence; Genes & Behavior
Link ID: 4102 - Posted: 06.24.2010

Mouse dementia model hints that protein prevents brain degeneration. HELEN R. PILCHER A protein called Pin1 may prevent degenerative brain disorders from developing. When it is removed, ageing mice develop symptoms similar to those of Alzheimer's disease, a new study reveals1. Future human therapies may seek to boost Pin1 levels. Pin1 is an enzyme. In the test tube, it hastens the untangling of clumps of a spaghetti-like protein called tau that build up inside sickly, ageing nerve cells. "By increasing Pin1 function in degenerating neurons, we might be able to protect the brain from Alzheimer's disease," says Kun Ping Lu of Harvard Medical School in Boston, who led the study. © Nature News Service / Macmillan Magazines Ltd 2003

Keyword: Alzheimers
Link ID: 4101 - Posted: 06.24.2010

Self-awareness makes some yawn-susceptible. HELEN PEARSON Self-aware or empathetic people are more likely to catch the yawns, say US researchers1. Contagious yawning is known to be more than coincidence. Studies have shown that 40-60% of people who watch videos or hear talk about yawning end up joining in. But psychologists have wondered what causes it. "It seems like such a hokey phenomenon," says psychologist Steven Platek at Drexel University in Philadelphia. Platek and his colleagues at the State University of New York in Albany sat subjects in front of videos of others yawning and tallied their responses to find out why people are susceptible or immune to contracting yawns. © Nature News Service / Macmillan Magazines Ltd 2003

Keyword: Emotions
Link ID: 4100 - Posted: 06.24.2010

St. Louis, –- Studying women with histories of clinical depression, investigators at Washington University School of Medicine in St. Louis found that the use of antidepressant drugs appears to protect a key brain structure often damaged by depression. Previous research has shown that a region of the brain involved in learning and memory, called the hippocampus, is smaller in people who have been clinically depressed than in those who never have suffered a depressive episode. Now, researchers have found that this region is not quite as small in depressed patients who have taken antidepressant drugs. The study, led by Yvette I. Sheline, M.D., associate professor of psychiatry, radiology and neurology, appears in the August issue of the American Journal of Psychiatry. The hippocampus is a part of the brain's limbic system, a group of structures important to emotion and motivation. Using high-resolution magnetic resonance imaging (MRI), Sheline's team measured hippocampal volumes in 38 women who had experienced an average of five episodes of major depression in their lifetimes. Only some of those episodes had been treated with antidepressant drugs.

Keyword: Depression
Link ID: 4099 - Posted: 06.24.2010

By ABRAHAM VERGHESE In the early mornings, when I head out to work, I often see the same middle-aged jogger go by, fussing with his stopwatch. Though his pace is rapid, it is also shuddering, like a cart with a wobbly wheel. I picture bone grinding on bone with no cartilage left to intervene. And yet it is not pain that shows on his face but pleasure. I speculate about this man even as I envy him. Exercise for him is its own reward. It is life affirming and it is his addiction. My addiction is tennis. In summer I may hobble around home and office, but on the court, once I hear the opening pop of a new can of balls, pain is forgotten, and I lunge and sprint with abandon. My game peaked 10 years ago and then came down to a steady club level. Since then, the biggest change is in the time it takes to recover from my on-court exertions. There was a week not long ago, for example, when I dreaded shaking hands because my elbow hurt, I limped from Achilles tendinitis, lying flat was preferable to sitting because my back ached and the Advil was taking its toll on my stomach. And yet, when my partner called to see if I would play, I couldn't get out the door fast enough. I felt comforted that even President Bush, a committed exerciser, had complained just that month of aching knees. Last month, it was revealed he had torn his calf muscle in April. He is no exception. On the courts, I see players his age, or mine (upper 40's), wearing strange patellar bands or air-filled forearm straps or thigh wraps or wrist braces, not to mention magnets parked over various body sites. No doubt at home they have gel packs cooling in the freezer and supersize bottles of Motrin. All for good health! Copyright 2003 The New York Times Company

Keyword: Pain & Touch
Link ID: 4098 - Posted: 07.27.2003

By RICHARD PÉREZ-PEÑA For several years, new drugs have offered powerful hope for people who suffer strokes, cutting the risk of death or disability. But the vast majority of stroke patients never get that medicine, because they are not treated quickly enough. New York City, New York State and several hospitals in Brooklyn and Queens have set out to change that, accelerating treatment in the precious first hours when a stroke patient's brain is being damaged beyond repair. That makes New York one of the few cities around the country to adopt practices that neurologists have spent years pushing for. The State Department of Health, which is overseeing the project, hopes to take it citywide and even statewide in the near future. Copyright 2003 The New York Times Company

Keyword: Stroke
Link ID: 4097 - Posted: 07.27.2003

By NICHOLAS WADE When Julius Caesar was touring the Spanish city of Cadiz in his early 30's, the ancient Roman biographer Suetonius reports, he came across a statue of Alexander the Great and wept beside it. Alexander at the same age had conquered the known world, while Caesar was just a minor Roman official, a source of severe chagrin to the ambitious future autocrat. It must be almost equally discouraging for scientists to see the graph that plots the age at which eminent male scientists make their big discoveries. It peaks at age 30 and then plummets, giving precious little time after one's hard-earned Ph.D. to get that invitation from the Nobel prize committee. The productivity of jazz musicians and painters is also highest in their mid-30's. And it's not just creativity that attains its zenith early in the male career. Crime, too, follows just the same parabolic curve. Dr. Satoshi Kanazawa, an evolutionary psychologist at the London School of Economics who has studied these patterns of male achievement, believes he has the explanation. Young men in any profession are driven to seek wealth and prestige because these attributes are attractive to women. Once men's urges to start a family have been satisfied, the wellsprings of productivity, whether in science, art or crime, run dry, Dr. Kanazawa suggests. Copyright 2003 The New York Times Company

Keyword: Sexual Behavior; Evolution
Link ID: 4096 - Posted: 07.27.2003

By PETER D. KRAMER PROVIDENCE, R.I. - A depressed patient tells me about her neighbor. He is suffering the crises that arise in the course of diabetes — first foot pain, now vision loss. He has remained upbeat throughout. "He's legally blind," my patient says. "I don't know how he can stand it." Amid the wonder, I sometimes hear a suggestion that the man lacks self-awareness. To this question, how some people cope, scientists have just now proposed a tentative answer. Humans, it seems, are constructed differently: adversity depresses some, but not others. A report in the current issue of Science looks at the effects of stressful events in early adulthood — and the way that responses to them are mediated by a single gene, called 5-HTT. This same gene was in the news in the 1990's, when its variant forms, long and short, were discovered. The gene makes a protein that modifies nerve cells' use of serotonin, a chemical messenger important in the regulation of mood. The short version of the gene was linked (if weakly) to neuroticism, as a personality trait — the news media called 5-HTT the "Woody Allen gene." Copyright 2003 The New York Times Company

Keyword: Depression; Genes & Behavior
Link ID: 4095 - Posted: 06.24.2010

Parents might in future have something a little more technical to discuss with teachers during consultation evenings than their offspring's writing, artwork and test results: brain scans. The prediction comes from two education professors who think neuroscience could transform education. John Geake of Oxford Brookes University and Paul Cooper of the University of Leicester say that recent research into the functioning of the human brain has greatly enhanced the understanding of learning, memory, intelligence and emotion. They are now working on applying this new knowledge specifically to education. In an article in the journal Westminster Studies in Education, they describe a parents' evening where a teacher shows a mother that her son has a weak short-term memory circuit for number solutions - explaining his poor maths work. The teacher recommends mental tasks to improve that aspect of the brain's function. The parent is pleased that teacher knows what is the matter and can so something about it. "This is a future fantasy scenario, let's be clear about that," Prof Geake told BBC News Online. (C) BBC

Keyword: Brain imaging
Link ID: 4094 - Posted: 07.26.2003

Bruce Bower The old saying that it's better to give than to receive may be true, at least when it comes to social support. Over a 5-year period, seniors who provided either a lot of practical assistance to friends, relatives, and neighbors or regular emotional support to their spouses displayed a higher survival rate than those who didn't provide such help, a new study finds. New data suggest that older people who provide social support to spouses, friends, and others live longer than other seniors do. In contrast, recipients of plentiful social support showed death rates similar to those of their peers who got little or no such support, say psychologist Stephanie L. Brown of the University of Michigan in Ann Arbor and her colleagues. Copyright ©2003 Science Service.

Keyword: Neuroimmunology; Stress
Link ID: 4093 - Posted: 06.24.2010

Two deaf mice may clarify a common childhood disorder By Laura Spinney A large-scale mouse-mutagenesis program in Harwell, UK, recently turned up two new models for the most common form of childhood deafness. Otitis media (OM), as the name implies, is an inflammation of the middle ear. Although believed to be triggered by infection, studies of twins indicate a complex genetic predisposition.1 Children who have malformed eustachian tubes--those with cleft palate or Down syndrome, for instance--seem to be particularly vulnerable. When OM is accompanied by the buildup of fluid, it is called OM with effusion, or "glue ear," and most children will experience at least one episode of this in their lives. The condition presents as partial deafness, and affected children cannot hear human speech, which can result in impaired social development. Surgery, which is recommended for the worst cases, involves drilling a tiny hole in the eardrum to allow the fluid to escape. As with all surgeries, however, the procedure carries risks. Researchers are trying to develop a new therapy for the most susceptible children. ©2003, The Scientist Inc.

Keyword: Hearing
Link ID: 4092 - Posted: 06.24.2010

St. Paul, MN – Boys are 28 percent more likely than girls to have a stroke, and black children are more than twice as likely to have a stroke as other ethnic groups, according to a study in the July 22 issue of Neurology, the scientific journal of the American Academy of Neurology. Researchers identified 2,278 first admissions for childhood stroke in a 10-year period in California by examining a statewide hospital discharge database. Children were one month through 19 years of age and were classified by their parent or guardian as white, black, Hispanic, Asian or other. Boys made up 51 percent of the population, and girls made up 49 percent. Ischemic stroke (the most common type of stroke, resulting from blocked arteries) accounted for 51 percent of the cases. Hemorrhagic stroke accounted for the rest, and was broken down into intracerebral hemorrhage (vessels bleed into the brain) and subarachnoid hemorrhage (abnormal vessels rupture near the membrane surrounding the brain). The annual stroke incidence rate was found to be 2.3 strokes per 100,000 children.

Keyword: Stroke
Link ID: 4091 - Posted: 06.24.2010

St. Paul, MN –After only three weeks of reading instruction, brain scans in children with dyslexia develop activation patterns that match those of normal readers, according to a new study published in the July 22 issue of Neurology, the scientific journal of the American Academy of Neurology. These findings indicate that children with dyslexia use the same regions of their brains as other readers, and that specialized instruction can rapidly compensate for some types of reading deficits. Dyslexic children in this study had above average intelligence but scored approximately 30 percent lower than average on standard reading tests. The dyslexic children and a group of good readers of the same age underwent functional magnetic resonance imaging (fMRI) to map their brain activation patterns during two types of reading tests. The children with dyslexia then received a three-week training program based on principles outlined by the National Reading Panel (www.nationalreadingpanel.org), convened by the National Institute of Child Health and Human Development. Both groups of children then underwent a second brain scan. The experiment was conducted during the summer, to avoid confounding effects from school instruction.

Keyword: Dyslexia
Link ID: 4090 - Posted: 06.24.2010

Schools are threatening to expel hyperactive children who do not take the controversial drug Ritalin, the BBC has learnt. Some parents are even being told that their children may be taken into care if they do not put their children on the drug. The claims come as a survey in Scotland suggests some youngsters are selling Ritalin to drug dealers or swapping it for CDs and phone cards. Parents' charity Overload Network International said the situation is so bad, some school secretaries and dinner ladies are having to hand out extra doses to children. The survey also revealed that some teenage girls have started taking the drug as a diet pill. Janice Hill of the charity has urged the government to step up controls of the drug to ensure it is not being abused. (C) BBC

Keyword: ADHD
Link ID: 4089 - Posted: 07.25.2003