Using brain cells from rats, scientists at The Johns Hopkins University School of Medicine and the University of Hamburg have manipulated a molecular "stop sign" so that the injured nerve cells regenerate. While their findings are far from application in people, the prospects for eventually being able to repair spinal cord injury are brighter, they say. "Four thousand years ago, physicians wrote that spinal cord injury was untreatable, and unfortunately it's much the same today," says Ronald L. Schnaar, Ph.D., professor of pharmacology and of neuroscience at Hopkins. "But the basic-science framework for improving this situation is quickly emerging."

Keyword: Regeneration; Development of the Brain
Link ID: 2255 - Posted: 06.21.2002

From The Economist print edition Researchers can now watch the brain as memories are stored within it BEFORE a big exam, a sound night's sleep will do you more good than poring over your textbooks. That, at least, is the folk wisdom. And science, in the form of behavioural psychology, supports that wisdom. But such behavioural studies cannot distinguish between two competing theories of why sleep is good for the memory. One says that sleep is when permanent memories form. The other says that they are actually formed during the day, but then “edited” at night, to flush away what is redundant. To tell the difference, it is necessary to peer into the brain of a sleeping person, and that is hard. But after a decade of painstaking work, a team led by Pierre Maquet of the Cyclotron Research Centre at Liège University in Belgium has managed to do it. Dr Maquet and his colleagues have persuaded enough people to fall asleep inside a noisy, cramped brain-scanning machine to collect the evidence needed to show what is happening. Steven Laureys, one of Dr Maquet's collaborators, revealed their results to a meeting of the Organisation for Human Brain Mapping in Sendai, Japan, earlier this month. Copyright © 2002 The Economist Newspaper and The Economist Group. All rights reserved.

Keyword: Learning & Memory; Sleep
Link ID: 2254 - Posted: 06.24.2010

UPTON, NY — The idea that obese people eat too much because they find food more palatable than lean people do has gained support from a new brain-imaging study at the U.S. Department of Energy’s Brookhaven National Laboratory. The study reveals that the parts of the brain responsible for sensation in the mouth, lips, and tongue are more active in obese people than in normal-weight control subjects. “This enhanced activity in brain regions involved with sensory processing of food could make obese people more sensitive to the rewarding properties of food, and could be one of the reasons they overeat,” said Brookhaven physician Gene-Jack Wang, lead author of the study. Wang acknowledges that obesity is a complex disease with many contributing factors, including genetics, abnormal eating behavior, lack of exercise, and cultural influences, as well as cerebral mechanisms, which are not yet fully understood. In a recent study, he and his team found that obese people have fewer brain receptors for dopamine, a neurotransmitter that helps produce feelings of satisfaction and pleasure, implying that obese people may eat to stimulate their underserved reward circuits, just as addicts do by taking drugs.

Keyword: Obesity; Brain imaging
Link ID: 2253 - Posted: 06.24.2010

Denied sugar, bingeing rats suffered withdrawal It's a common refrain: "I'm addicted to sugar." Now a study by Princeton University psychologists suggests that such urges really may be a form of addiction, sharing some of the physiological characteristics of drug dependence. Although the term "sugar addiction" often appears in magazines and on television, scientists had not demonstrated that such a thing as sugar dependency really exists, said neuroscientist Bart Hoebel, who led the study. Hoebel and colleagues studied rats that were induced to binge on sugar and found that they exhibited telltale signs of withdrawal, including "the shakes" and changes in brain chemistry, when the effects of the sweets were blocked. These signs are similar to those produced by drug withdrawal. Sugar, said Hoebel, triggers production of the brain's natural opioids. "We think that is a key to the addiction process," he said. "The brain is getting addicted to its own opioids as it would to morphine or heroin. Drugs give a bigger effect, but it is essentially the same process."

Keyword: Obesity; Drug Abuse
Link ID: 2252 - Posted: 06.21.2002

Copyright © 2002 United Press International BALTIMORE, - Scientists announced Wednesday they have figured out a new way to get nerve cells to regenerate in the laboratory and have come one step closer to being able to repair spinal cord injuries - although that prospect remains years away. "For the first time in history there is some optimism that we may be able to get functional recovery of spinal cord injuries," Ronald L. Schnaar, co-author of the study and professor of pharmacology and of neuroscience at Johns Hopkins University, told United Press International. "Whether it's this decade or next decade, I think we'll begin to see this knowledge turned into therapies." Schnaar and colleagues at the University of Hamburg, Germany, discovered how to modulate a molecular signal that inhibits the regeneration of nerve cells after they are damaged. Copyright © 2001 Nando Media

Keyword: Regeneration; Brain Injury/Concussion
Link ID: 2251 - Posted: 06.24.2010

BY FAYE FLAM Knight Ridder Newspapers PHILADELPHIA - (KRT) - A scan of brain activity may reveal aspects of one's personality, scientists said Thursday, raising both the possibility of new treatments for mental illness and the specter of Orwellian "thought police." In a report published Friday, researchers said they can roughly distinguish loners from social butterflies by putting them under brain-scanning equipment and showing them pictures of happy faces. The more extroverted the test subject, the more brain structures seemed to light up at the sight of a smiling person. © 2002, The Philadelphia Inquirer.

Keyword: Brain imaging; Emotions
Link ID: 2250 - Posted: 06.24.2010

The controversy surrounding stem cell research—in particular whether the cells should come from embryonic sources or adult ones—hinges on what, exactly, cells from the two sources are capable of. Embryonic stem cells, which are more politically contentious because they must be harvested from human embryos, can differentiate into any tissue in the human body. Adult stem cells, although available from less controversial sources, have so far shown less plasticity than their embryonic counterparts. Now the results of two studies published online by the journal Nature provide additional insight into the abilities of both classes of stem cells. The findings further suggest that only by investigating the two kinds of stem cells will it be possible to determine which source will prove most useful in treating a particular disease. Catherine Verfaillie and of the University of Minnesota Stem Cell Institute and her colleagues report that a particular kind of adult stem cell, derived from bone marrow and dubbed a multipotent adult progenitor cell (MAPC), can differentiate into nearly all types of mouse tissue. The scientists injected MAPCs into mice blastocysts (embryos comprised of approximately 100 cells), which were then transferred to foster mothers for gestation. The resultant animals exhibited multiple tissue types, including brain, lung, retina, spleen and skin, attributable to the MAPCs. "Some of the animals are 40 percent derived from the bone marrow stem cells, suggesting that the cells contribute functionally to a number of organs," Verfaillie notes. "This is similar to what one would expect of [embryonic stem] cells." The team next injected MAPCs into a living animal and found that the cells still differentiated into liver, intestine and lung tissue, but overall MAPCs were detected in fewer tissue types than in the blastocyst-injected mice. © 1996-2002 Scientific American, Inc. All rights reserved.

Keyword: Stem Cells; Parkinsons
Link ID: 2249 - Posted: 06.24.2010

Even short-term use of ecstasy can damage the memory, researchers have found. A study by scientists at the University of Cambridge and the University of East London in the UK showed ecstasy users performed worse in tests than people who used other drugs. The researcher who led the study said her findings, and other evidence about long-term problems caused by ecstasy use, meant the drug should not be reclassified from Class A to Class B, as a Home Office committee has suggested. But campaigners for DrugScope said it was hard to determine whether the results of this and other similar studies were significant. (C) BBC

Keyword: Learning & Memory; Drug Abuse
Link ID: 2248 - Posted: 06.21.2002

Secretion of a stress hormone called cortisol and activation of the sympathetic nervous system are components of the classic "fight or flight" response to danger. A common source of cortisol release and increased cardiovascular activity is public speaking. A study in the June issue of Alcoholism: Clinical & Experimental Research builds upon previous work by comparing the cardiovascular responses of alcoholics and nonalcoholics to the psychological challenge of public speaking in relation to the physical challenge of standing (orthostasis). "Since cortisol is central to our ability to handle stress," said William R. Lovallo, Director of the Behavioral Sciences Laboratories at the Veterans Affairs Medical Center, Oklahoma City and corresponding author for the study, "we were surprised several years ago when we found that patients with alcohol dependence had cortisol responses that were absent or greatly attenuated. It didn't matter if the patient was asked to hold a hand in ice water, squeeze a hand-exercise device until it hurt, do mental arithmetic problems, or perform in a public-speaking simulation. Due to this cortisol response deficit, we suspected that these patients might also have a reduced fight or flight response. Most persons see public speaking as socially threatening, and they respond with the primitive fight or flight mechanism." Before testing alcoholics for their responses to a public-speaking task, researchers first needed to establish if their sympathetic nervous system was able to respond at all. "This would tell us if their blunting was specific to psychological stressors like public speaking," said Lovallo, "or due to a generalized autonomic deficit."

Keyword: Drug Abuse; Stress
Link ID: 2247 - Posted: 06.21.2002

Because people recognize the same emotions across languages and cultures, psychologists have long suspected that a person's ability to perceive basic emotions is innate. However, a new study published in the June 18 early edition of the Proceedings of the National Academy of Sciences suggests that experience can alter the way people see emotions. Led by University of Wisconsin-Madison psychologist Seth Pollak, the study examined how children categorize facial expressions as happy, sad, angry or fearful based on one particular emotional experience - physical abuse. Studying children who had been abused, Pollak says, offered an opportunity both to examine the effects of atypical experience on how children think about emotions and to possibly identify new interventions that could help abused children more effectively manage resulting behavioral problems. For this study, Pollak invited both abused and non-abused children, 8 to 10 years old, to his Child Emotion Research Laboratory. There, they played computer "games" that presented digitally morphed photos of facial expressions that ranged from either happy to fearful, happy to sad, angry to fearful or angry to sad. While some of the faces expressed a single emotion, most were blends of two emotions.

Keyword: Emotions
Link ID: 2246 - Posted: 06.21.2002

By ANNE EISENBERG IN the 2001 movie "Memento," the hero cannot hold onto any new memories. He forgets whatever he sees or hears within moments, distracted by new events that he also forgets in turn. Profound amnesia like this comes about in real life, too, from trauma or disease to the hippocampus, the cortical section of the brain where memories are formed. One day, though, a computer chip may do some of the work of a damaged hippocampus, replacing living neurons with silicon ones. That is the goal of Dr. Theodore W. Berger, a professor of biomedical engineering at the University of Southern California in Los Angeles and the director of the Center for Neural Engineering there. Dr. Berger has spent the past decade developing some of the basics for a chip-assisted hippocampus. Copyright 2002 The New York Times Company

Keyword: Learning & Memory; Robotics
Link ID: 2244 - Posted: 06.21.2002

A woman who lost nearly three stone in 11 months suffered a brain illness normally associated with alcoholics. Her condition mystified doctors because she insisted she was on a healthy, balanced, diet throughout. Doctors say that either her own genetic makeup - or perhaps the herbal diet supplement she was taking might be to blame. The 30-year-old, who was 11.5 stone before she began dieting, developed a condition called Wernicke's encephalopathy. Wernicke's encephalopathy usually develops suddenly, and involves involuntary, jerky eye movements or paralysis of muscles moving the eye, coupled with poor balance, staggering gait or inability to walk. When the condition, caused by a severe lack of vitamin B1, is diagnosed, doctors normally link it to heavy drinking. (C) BBC

Keyword: Anorexia & Bulimia
Link ID: 2243 - Posted: 06.11.2002

A simple one-hour brain scan may be able to predict who will be helped by antidepressants and who will not. Researchers have detected signs of changes to patients' brain waves weeks before they showed any visible benefits from taking medication. The scientists, led by Dr Ian Cook from the University of California Los Angeles, say the method could minimise the waste of drugs on patients who are unlikely to respond positively. This is doubly important, as the drugs are expensive and can have side effects. Dr Cook said: "This is the first study to detect specific changes in brain wave activity that precede the clinical changes in a way that can usefully predict response." Up to 40% of depressed patients do not respond to the first medication they try. (C) BBC

Keyword: Depression; Brain imaging
Link ID: 2242 - Posted: 06.11.2002

A common mutation in a gene that controls the breakdown of the brain's natural cannabinoids contributes to drug abuse and addiction, new US work suggests. Scientists at the Scripps Research Institute, California, questioned more than 1000 people attending a medical clinic on their drug use, including use of nicotine and alcohol. They found that people who reported abusing illegal drugs were four times more likely to have two copies of the mutated gene than people without drug or alcohol problems. About 3.7 per cent of the people in the study had this double mutation, the team says. The gene encodes an enzyme called fatty acid amide hydrolase (FAAH). This enzyme is responsible for inactivating endogenous cannabinoids - which act on the same neuroreceptors as the psychoactive component of marijuana. Previous work has suggested that the enzyme is involved in reward and addiction pathways in the brain. The common mutation in the gene causes a build-up of natural cannabinoids. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse; Genes & Behavior
Link ID: 2241 - Posted: 06.24.2010

Since their introduction 15 years ago, antidepressants have been widely used to treat psychiatric disorders in adults. In recent years, antidepressants have been increasingly prescribed for children and adolescents as well, despite very little data to support such use. In a study published in the May issue of Pediatrics , Julie Magno Zito, Ph.D., and colleagues explored some of the reasons for this trend and highlighted the associated dangers. Zito may be familiar to readers for her research that brought the increasing use of psychotropics in children to national attention when it was published in JAMA in 2000. For the current study, researchers retrospectively evaluated prescription and clinical service records for nearly 1 million youths ages 2 to 19 years, using data sets for each year from 1988 to 1994. Subjects were enrolled in either a state Medicaid program or a group HMO. Prevalence of antidepressant use was found to have increased three- to five-fold in the study period for all three major subclasses defined in the study (tricyclic antidepressants, selective serotonin reuptake inhibitors and other antidepressants). While TCAs were the most prescribed psychotropic in 1988, by 1994, SSRI prescriptions nearly reached their numbers. © 2002 Psychiatric Times. All rights reserved.

Keyword: Depression; Development of the Brain
Link ID: 2240 - Posted: 06.24.2010

by Laura J. Miller, M.D. Psychiatric Times June 2002 Vol. XIX Issue 6 After reading this article, you will be familiar with: * Research criteria used to diagnose premenstrual dysphoric disorder (PMDD). * Possible causes of PMDD. * Nonpharmacological treatment strategies, including dietary modification, psychotherapy and aerobic exercise. * Pharmacological interventions for PMDD, including selective serotonin reuptake inhibitors, anxiolytics and agents to suppress ovulation. Although the idea that some women experience mood changes linked to their menstrual cycles has a long history, it is only recently that systematic and methodologically sound studies are revealing the relationship between mood and menses. (C) 1995-2003 CME, Inc.

Keyword: Hormones & Behavior; Depression
Link ID: 2239 - Posted: 06.11.2002

Athletes gain bigger bodies at high health risk Christopher Heredia, Chronicle Staff Writer Recent revelations by star baseball players Jose Canseco and Ken Caminiti that steroid use is rampant in the game has reignited an age-old debate about the health consequences of the drugs. Doctors warn about the dangers of steroids, citing reported health risks from heart disease and cancer to shrinking of the testicles. Athletes, meanwhile, say their predecessors going back to the 1950s used steroids without serious health consequences. Now, once again, athletes are demanding, "Show me the science." ©2002 San Francisco Chronicle.

Keyword: Hormones & Behavior
Link ID: 2238 - Posted: 06.24.2010

By ERICA GOODE When a teenage girl develops anorexia, a team of experts usually takes charge of bringing her back to a normal weight, while her parents stand on the sidelines. But a promising and controversial new therapy gives parents the primary responsibility for an anorexic child's recovery. The goal of the therapy is to mobilize the family as a whole in a fight against the eating disorder, said Dr. James Lock, an associate professor of psychiatry at Stanford School of Medicine and the lead author of an extensive treatment manual for the technique, published last year by Guilford Press. Copyright 2002 The New York Times Company

Keyword: Anorexia & Bulimia
Link ID: 2237 - Posted: 06.11.2002

Computers train and monitor animal detectives. JOHN WHITFIELD Computers could one day train squads of animals to detect smuggled drugs or explosives, and then monitor their performance as they go about their jobs, say US researchers1. Computer scientist James Otto, of the University of Baltimore, and his colleagues teach rats to rear up on their hind legs when they smell a cocaine mimic in the lab. A motion sensor on the rat detects this, and alerts a computer to the rat's location. A food dispenser linked to the motion sensor automates the training. By hiding the chemical with food, the researchers teach rats to associate finding the contraband with a treat. Then they begin dropping food from above, making the rats stand up. After 2-3 weeks' training in the lab, the smell of cocaine alone makes the rats stand upright more than 90% of the time. * Otto, J., Brown, M. F. & Long, W. III Training rats to search and alert on contraband odors. Applied Animal Behaviour Science, 77, 217 - 232, (2002). © Nature News Service / Macmillan Magazines Ltd 2002

Keyword: Chemical Senses (Smell & Taste)
Link ID: 2236 - Posted: 06.24.2010

A new UCLA Neuropsychiatric Institute study shows for the first time that measurable changes in the front of the brain can predict the effectiveness of an antidepressant within days of treatment — weeks before a patient begins to feel better. Using quantitative EEG, a non-invasive computerized measurement of brain wave patterns, the researchers discovered that specific changes in brain-wave activity precede clinical changes brought on by medication. The new findings, published in the July edition of the peer-reviewed journal Neuropsychopharmacology, could lead to treatment programs that help depression patients feel better faster by cutting evaluation periods from weeks to days. The findings also could aid in the development of new medications. "Up to 40 percent of depressed patients do not respond to the first medication they try. Since it takes several weeks for an effective treatment to produce clear improvement, doctors often wait six to 12 weeks to decide that a particular medication just isn't right for that patient and move on to another treatment," said Dr. Ian A. Cook, a researcher at the institute's Quantitative EEG Laboratory and lead author of the study.

Keyword: Depression
Link ID: 2235 - Posted: 06.24.2010