Howard Hughes Medical Institute researchers have identified a circuit in the brain that appears crucial in converting short-term memories into long-term memories. The circuit links the major learning-related area of the brain to another region that governs the brain's higher functions. The studies open the way for eavesdropping on one of the central processes in learning and memory, says HHMI investigator Erin M. Schuman. She and graduate student Miguel Remondes of the California Institute of Technology published their findings in the October 7, 2004, issue of the journal Nature. According to Schuman, the finding sheds light on a central question in learning and memory research that concerns the roles of two brain structures, the hippocampus, which is involved in memory formation, and the neocortex, which is associated with higher brain functions. “There are two key findings required to understand the present work,” said Schuman. “First, lesions of the hippocampus prior to training can prevent the formation of some kinds of short-term memory. Second, if one delays the hippocampal lesion to days after training, one can observe that as the delay increases, the memory deficit decreases. These data suggest that the importance of the neocortex as a memory storage site increases with the lifetime of the memory. In addition, there is a clear need for the hippocampus and cortex to talk to one another.” © 2004 Howard Hughes Medical Institute.

Keyword: Learning & Memory
Link ID: 6205 - Posted: 06.24.2010

By MARTIN FINUCANE, The Associated Press BOSTON - An appetite-curbing hormone that failed to live up to its early buzz as a possible key to slowing obesity is now being probed as a potential aid for women who suffer from infertility and eating disorders. "This represents essentially a new era for leptin," said Dr. Jean Chan, one of the researchers exploring new uses for the hormone. "Now that we understand so much more about what this hormone does, we can target it appropriately for the right condition." A very small study, led by researchers at the Beth Israel Deaconess Medical Center and at Massachusetts General Hospital and published recently in the New England Journal of Medicine, found that leptin restored menstrual periods in a few female athletes who hadn't had periods for an average of 5 1/2 years. Authors of the study also said there were some preliminary signs that the hormone improved bone density, which begins to decline when women stop menstruating. Women with low body fat, including athletes and those with eating disorders, often stop menstruating, developing a condition called hypothalamic amenorrhea. © 2004 The Associated Press

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 6204 - Posted: 06.24.2010

Since its introduction four decades ago, the birth control pill has not entirely lived up to its original hype: While it may have offered women sexual freedom, the pill has also introduced a number of hormone-related side effects and health issues—everything from intense mood swings to a possible risk of cancer. Though we're of course much better off than in the precarious days of the "rhythm" and "withdrawal" methods, birth control remains a stressful business: Should I stay with condoms, even though they're uncomfortable and fail 10 percent of the time? Should I risk the side effects and go on the pill? Should I resort to something as clumsy and dated as a diaphragm? But even with so many issues still on the table, one seems to have been long ago put to bed: Birth control is unquestionably a woman's responsibility. Or is it? A remarkable new product is on its way that may make it possible to shift the burden of reproductive responsibility—gasp!— to men. Earlier this year, Dutch pharmaceutical giant Organon, along with Germany's Schering, announced that they expect their hormone-based contraceptive for men to hit the European market in as few as five years. Once that happens, it may only be another year or so before a U.S. debut. So, it will soon be possible for a man to avoid impregnating his partner by drastically lowering his sperm count. Unlike a vasectomy, the effect is temporary, completely reversible. And of course, the very notion is incredible: For over 30 years a "male pill" has been in various stages of development, but this is the first time serious drug money has backed it up. As a woman, I can't help but ask: What took so long? ©2004 Microsoft Corporation.

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 6203 - Posted: 06.24.2010

ST. LOUIS -- Nerve cells with a mutant calcium channel don't communicate as effectively as those with a normal calcium channel, according Saint Louis University research that is published in the Proceedings of the National Academy of Sciences Online Early Edition the week of Oct. 4. "The research helps us understand the basic mechanism that underlies how neurons communicate," said Amy Harkins, Ph.D., assistant professor of pharmacological and physiological science at Saint Louis University School of Medicine and principal investigator. "The entry of calcium into cells is a very important process that allows muscles to contract, the heart to beat and nerve cells to communicate with one another. The research is teaching us how a very integral part of our cellular structure works." Communication between nerve cells occurs when calcium enters a nerve cell and causes the cell to release a chemical called a neurotransmitter that then carries a signal to other nerve cells. Calcium cannot freely enter cells, and must wait for an opening of a molecular gate, which is called a calcium channel.

Keyword: Miscellaneous
Link ID: 6202 - Posted: 10.06.2004

Helen Pearson One of the most promising experimental therapies for Parkinson's disease could be shelved after scientists revealed today that a clinical trial has been stopped because of safety concerns. During the treatment, a protein called glial-derived neurotrophic factor (GDNF) is drip-fed into the brains of patients with the movement disorder. The idea is that the protein will nourish dopamine-manufacturing brain cells, which shrivel up during the disease. Hopes for the treatment soared last year when it was announced that the first five people treated with GDNF experienced a dramatic recovery in their movements1. Scientists think the therapy is particularly exciting because it is one of the few that attempts to preserve or pep up fading brain cells, rather than simply treating the symptoms of the disease. But on Tuesday, Anthony Lang of Toronto Western Hospital in Canada revealed that a second, more extensive clinical trial of GDNF has been halted because the drug showed little signs of working and some potentially dangerous side effects. Lang, who was one of the trial's lead investigators, discussed the results at the annual meeting of the American Neurological Association in Toronto. ©2004 Nature Publishing Group

Keyword: Parkinsons
Link ID: 6201 - Posted: 06.24.2010

ST. LOUIS -- Testosterone -– the hormone responsible for a man's sex drive -– may help him recover from a stroke, according to preliminary animal research at Saint Louis University. Researchers will present their findings at the annual meeting of the American Neurological Association in October. "It looks like testosterone speeds up the recovery from a stroke," said Yi Pan, M.D., Ph.D., assistant professor of neurology at Saint Louis University School of Medicine and principal investigator on the study. "While the results are encouraging, this is still very preliminary and we need to do more research." The scientists compared two groups of castrated rats that had suffered strokes. Half received testosterone and half a placebo. The rats that received testosterone showed significant improvement in neurological deficits while those in the control group did not. Based on the promising findings, plans are on the drawing board to test whether testosterone helps people recover from strokes, said Aninda B. Acharya, M.D., assistant professor of neurology at Saint Louis University School of Medicine and a researcher on the project.

Keyword: Stroke; Hormones & Behavior
Link ID: 6200 - Posted: 06.24.2010

By JAMES GORMAN What would Cyrano de Bergerac say? That was the question that came to mind after reading an article on "Cosmetic Neurology" published last week in Neurology. I suspect he would read the title of the article, take note of the subtitle, "The controversy over enhancing movement, mentation and mood," raise his eyebrows, put his hand on the hilt of his rapier and exclaim, "What?" or, if you want to be picky, "Quoi?" Cyrano himself is not around, of course, so I had to contact the author of the article myself to ask about the title. The substance of the article is clear. Dr. Anjan Chatterjee, of the department of neurology and the Center for Cognitive Neuroscience at the University of Pennsylvania, discussed the many ways that exist and are emerging to tinker with emotions, intellect, memory and other aspects of ourselves by choice. Beyond therapy for mental or physical illness, he said, neurologists in particular will be in the middle of societal demands for drugs to improve attention and mood simply because people want them. Copyright 2004 The New York Times Company

Keyword: Miscellaneous
Link ID: 6199 - Posted: 10.05.2004

On a spring day two years ago, in a downtown Columbus auditorium, the Ohio State Board of Education took up the question of how to teach the theory of evolution in public schools. A panel of four experts - two who believe in evolution, two who question it - debated whether an antievolution theory known as intelligent design should be allowed into the classroom. This is an issue, of course, that was supposed to have been settled long ago. But 140 years after Darwin published On the Origin of Species, 75 years after John Scopes taught natural selection to a biology class in Tennessee, and 15 years after the US Supreme Court ruled against a Louisiana law mandating equal time for creationism, the question of how to teach the theory of evolution was being reopened here in Ohio. The two-hour forum drew chanting protesters and a police escort for the school board members. Two scientists, biologist Ken Miller from Brown University and physicist Lawrence Krauss from Case Western Reserve University two hours north in Cleveland, defended evolution. On the other side of the dais were two representatives from the Discovery Institute in Seattle, the main sponsor and promoter of intelligent design: Stephen Meyer, a professor at Palm Beach Atlantic University's School of Ministry and director of the Discovery Institute's Center for Science and Culture, and Jonathan Wells, a biologist, Discovery fellow, and author of Icons of Evolution, a 2000 book castigating textbook treatments of evolution. Krauss and Miller methodically presented their case against ID. "By no definition of any modern scientist is intelligent design science," Krauss concluded, "and it's a waste of our students' time to subject them to it." © Copyright© 1993-2004 The Condé Nast Publications Inc.

Keyword: Evolution
Link ID: 6198 - Posted: 06.24.2010

Despite the well-characterized cellular basis of Parkinson's disease -- the degeneration of dopamine-production neurons -- the molecular mechanisms responsible for the neurodegeneration remain unknown. Part of the challenge is finding a model that can adequately mimic the loss of dopamine cells. In two papers published in PLoS Biology, Asa Abeliovich and colleagues make the case that a model based on mouse embryonic stem cells offers a promising platform for dissecting the disease mechanism of Parkinson's. Working with these cells, the researchers created dopamine neurons deficient in DJ-1, a gene mutated in an inherited form of Parkinson's. They report that DJ-1-deficient cells -- and especially DJ-1-deficient dopamine neurons -- display heightened sensitivity to oxidative stress, caused by products of oxygen metabolism that react with and damage cellular components like proteins and DNA. In a second paper, they link DJ-1 dysfunction to the aggregation of alpha-synuclein, a hallmark of Parkinson's neuropathology. Oxidative stress has long been associated with neuronal cell death and neurodegenerative diseases like Parkinson's. Proving a causal relationship between oxidative stress and neurodegeneration, however, requires establishing a molecular mechanism. These results support a link between oxidative damage and disease, and provide a tractable model for both studying the molecular mechanisms of neurodegenerative disease and screening potential neuroprotectant drugs. The authors are hoping to extend their work to human embryonic stem cells, but their work is limited by the availability of such cells under the current NIH guidelines.

Keyword: Parkinsons
Link ID: 6197 - Posted: 10.05.2004

Parents who complain about their lazy teenagers, take note—new research is revealing that laziness could be programmed in growing teens' brains, and can lead some kids to risky behavior. James Bjork, a neuroscientist at the National Institute on Alcohol Abuse and Alcoholism, used magnetic resonance imaging (MRI) to study the brains of 12 adolescents (ages 12-17) and 12 adults in their twenties (22-28). While being scanned, both groups played a computer game using monetary gain or loss as a motivator. Bjork reported in the Journal of Neuroscience that even though both teen and adult brains showed a high desire to win, a different area of the brain lit up much less in the teen brains. "What we found is that the parts of the brain that are in the frontal lobe, that tend to assign picture value to rewards in the environment—the enjoyment of, say, having won five bucks—[were] the same in adolescents and adults," explains Bjork, "but what was deficient in the adolescents is the circuitry at the base of the brain in a region called the ventral striatum…and that region is a motivational center. It energizes action toward a goal. And we found that that was markedly deficient in the adolescents. This is despite the fact that questionnaires after the test indicated that the adults and the adolescents were equally happy and excited about the prospect of winning five dollars. But the adolescent brains didn't show in the actual circuitry and their activation in their brain." © ScienCentral, 2000- 2004.

Keyword: Development of the Brain; Hormones & Behavior
Link ID: 6196 - Posted: 06.24.2010

For some people, learning a new language is a frustrating struggle, while for others it seems no harder than falling off a log backwards. No one knows what makes someone a whiz at picking up foreign languages. One possibility is that the brain is more efficient at temporarily storing the sounds of unfamiliar words. To test this idea, a team led by Michael Chee, a cognitive neuroscientist at Singapore General Hospital, tested the ability of 30 young adults to learn words in French, a language none spoke. All of the subjects were native English speakers, but 10 years of studying Chinese had resulted in fluency for only half. Using magnetic resonance imaging, the researchers looked for differences in blood flow to certain parts of the brain. Chee's team found a significant difference between a language juggler and a language struggler, they report in the 4 October online edition of the Proceedings of the National Academy of Sciences. Subjects who had been unable to master Chinese showed relatively greater blood flow in the brain while learning French vocabulary than did those who had become bilingual. This was particularly the case in the left insular, a part of the brain thought to handle unfamiliar words before they can be laid down in long-term memory. These subjects also showed greater activation in parts of the brain normally used during difficult mental tasks. Chee concludes that the brain is working less efficiently in one group than the other, which could explain why the same efforts in school seem to have yielded such different language abilities. It's still an open question whether these neural differences are the cause or consequence of differing language abilities, he says. Copyright © 2004 by the American Association for the Advancement of Science.

Keyword: Language
Link ID: 6195 - Posted: 06.24.2010

CHICAGO – Patients with deficit schizophrenia, a subtype of schizophrenia characterized by "negative" symptoms, such as blunted speech and expression, lack of emotional response, and apathy, are more likely to have been born in the summer months, according to an article in the October issue of The Archives of General Psychiatry, one of the JAMA/Archives journals. According to the article, winter birth was reported to be a risk factor for schizophrenia in 1929. Clinical aspects of patients with schizophrenia born in the winter include paranoia and a more benign course of illness. Additionally, the clinical features associated with winter birth are different from patients with deficit schizophrenia, defined by the presence of negative symptoms, including inability to experience pleasure, lack of interest in socializing, speech deficits, blunted emotional response, poor eye contact, and more severe course of illness. Nondeficit schizophrenia is characterized by symptoms including hallucinations, incoherent thinking, and prominent delusions. Erick Messias, M.D., M.P.H., of The Johns Hopkins University, Baltimore, Md., and colleagues analyzed published and unpublished data from the northern hemisphere on studies of season of birth with information on schizophrenia and its subtype- deficit or nondeficit. A total of 1,594 patients were included in the nine studies examined.

Keyword: Biological Rhythms; Schizophrenia
Link ID: 6194 - Posted: 06.24.2010

CHICAGO – The use of fluoxetine (an antidepressant) or comprehensive cognitive behavioral therapy (CCBT) were similarly effective for treating social phobia, while combining these treatments did not provide further benefit, according to an article in the October issue of The Archives of General Psychiatry, one of the JAMA/Archives journals. According to the article, as many as 14 percent of people in the United States experience social phobia, also known as social anxiety disorder. Previous studies have shown that selective serotonin reuptake inhibitors (SSRIs) and cognitive behavioral treatments (CBTs) have been effective in treating social phobia. Jonathan R.T. Davidson, M.D., from Duke University Medical Center at Durham, N.C., and colleagues compared the efficacy of fluoxetine, CCBT, placebo, CCBT plus fluoxetine, and CCBT plus placebo in 295 patients with generalized social phobia. Of the study participants, 156 were male and 226 (76.3 percent) were white, with an average age of 37.1 years. Treatment lasted for 14 weeks, with fluoxetine and placebo administered in 10 mg/day to 60 mg/day doses. Those receiving group CCBT attended sessions one day a week for the 14 weeks. The sessions included specific social skills training (for example, how to begin a conversation with a stranger), role playing, and cognitive restructuring.

Keyword: Depression; Emotions
Link ID: 6193 - Posted: 06.24.2010

By Jennifer Viegas, Discovery News — Modern humans made direct contact with a now-extinct early human species, according to a new study of head lice. The species probably was Homo erectus, a chinless individual with a large projecting face, a prominent brow ridge, and a brain that was smaller than ours is today, the study said. The lice research, which involved both observational and DNA analysis, also provides a mini-history of human evolution from 5.5 million years ago to the present. Scientists believe the historical evidence is recorded in the genetic makeup of lice that can be found on the heads of many kids and others infected with the pesky parasites. Two related press releases issued by the University of Utah and the University of Florida explain that humans inflicted with head lice today can harbor two genetically distinct types. The first, found worldwide, evolved on our Homo sapiens ancestors. The second, only found in the Americas, evolved on another species of human that researchers believe was Homo erectus. Copyright © 2004 Discovery Communications Inc.

Keyword: Evolution
Link ID: 6192 - Posted: 06.24.2010

High blood pressure in otherwise healthy adults between the ages of 18 and 83 is associated with a measurable decline in cognitive function, according to a report published today by University of Maine researchers in the pre-publication online edition of the journal Hypertension. The article will appear in the October issue of the printed journal. While they characterize the decline as "relatively minor and manageable in terms of everyday functioning," the authors underscore the importance of treatment for high blood pressure. In their study, younger individuals (18-47) performed at a higher level than older individuals (48-83), but they, like older individuals, showed blood pressure-related decline in cognitive function over time. The study "breaks new ground," and "has far-reaching public health implications," according to an editorial by medical researchers in Belgium and the Netherlands published in the same issue of the journal. It extends what has been viewed as a problem of the elderly to younger people. Hypertension is published by the American Heart Association.

Keyword: Miscellaneous
Link ID: 6191 - Posted: 10.05.2004

Alison Abbott Our ability to smell, known as 'olfaction', is a potent yet often neglected player in our sensory world, and a surprising 3% of our genes are dedicated to fine-tuning its subtleties. The Nobel Prize committee has now honoured two scientists who have done most to determine just how we recognize and differentiate the scents of roses, wines, or of good or bad meat. Their work also helps explain how an evocative smell can take us back to a poignant time in our lives. Neuroscientists Richard Axel from Columbia University in New York and Linda Buck from the Fred Hutchinson Cancer Research Center in Seattle share this year's US$1.4-million Nobel Prize in Physiology or Medicine. Exploiting state-of-the-art molecular techniques over the past two decades, they have developed a complete picture of how a scent is converted into a signal in the brain, where it is not only recognized, but remembered in association with accompanying emotions. ©2004 Nature Publishing Group

Keyword: Chemical Senses (Smell & Taste)
Link ID: 6190 - Posted: 06.24.2010

By Rick Weiss Convinced they have sound science on their side, advocates for the medical use of marijuana plan to launch a novel effort today to get the federal government to ease restrictions on the illicit drug. Americans for Safe Access, a Berkeley, Calif., coalition of patients and doctors wanting easier access to pot for research and patient use, plans to file a petition with the Department of Health and Human Services charging the agency with spreading inaccurate information about the drug's medical value. Unlike previous efforts to ease marijuana access, which relied on the courts and have dragged on for years, the petition invokes the Data Quality Act, a little-known but powerful law that gives people the right to challenge scientific information disseminated by federal agencies. The law demands that agencies respond to petitions within two months. The act's use by marijuana advocates represents a peculiar political twist. The act was written by a tobacco industry lobbyist and slipped into a huge piece of legislation after the 2000 election without any congressional discussion or debate. It has been used almost exclusively by corporations challenging the validity of scientific information that they fear might lead to costly regulations. © 2004 The Washington Post Company

Keyword: Drug Abuse
Link ID: 6189 - Posted: 06.24.2010

Research Showing Men and Women Differ in More Than One Area By Amanda Onion — Men and women may really be from the same planet, but research is yielding mounting evidence that our brains are more different than we might think. From the way we record information to how we process language to the size of our brains and different regions of the brain, clear differences have emerged through animal studies and the use of technology such as brain scanning. Scientists are also trying to get at the roots of what may be behind these differences by looking at the effects of chromosomes and hormones at work in lab animals. And this is just the beginning. Jill Goldstein, a professor of psychiatry at Harvard Medical School, argues that social climates have only recently made such research acceptable. "When I was growing up, to say there were sex differences in the brain, you weren't even supposed to talk about it," said Goldstein. "I think we're living in a time now when we can look at what some of these differences are without saying they are necessarily deterministic."

Keyword: Sexual Behavior
Link ID: 6188 - Posted: 06.24.2010

The Nobel Assembly at the Karolinska Institute announced this morning that the 2004 Nobel Prize in Physiology or Medicine was awarded to Richard Axel, an HHMI investigator at Columbia University College of Physicians and Surgeons, and Linda Buck, an HHMI investigator at the Fred Hutchinson Cancer Research Center. The scientists were honored for their discoveries that clarify how the olfactory system works. Axel and Buck discovered a large gene family, comprised of some 1,000 different genes (three per cent of human genes) that give rise to an equivalent number of olfactory receptor types. These receptors are located on the olfactory receptor cells, which occupy a small area in the upper part of the nasal epithelium and detect the inhaled odorant molecules. In 1991 Axel and Buck—who was then a postdoctoral fellow in Axel's lab—discovered a family of genes that encode the odorant receptors of the olfactory epithelium, a patch of cells on the wall of the nasal cavity. The olfactory epithelium contains some 5 million olfactory neurons that send messages directly to the olfactory bulb of the brain. When an odor excites a neuron, the signal travels along the nerve cell's axon and is transferred to the neurons in the olfactory bulb. This structure, located in the very front of the brain, is the clearinghouse for the sense of smell. From the olfactory bulb, odor signals are relayed to both the brain's higher cortex, which handles conscious thought processes, and to the limbic system, which generates emotional feelings. © 2004 Howard Hughes Medical Institute.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 6187 - Posted: 06.24.2010

You try listening to a tape of mellow ocean sounds, wearing an aromatherapy eye mask, even the old standby, counting sheep. Nothing works. You toss and turn. Toss and turn. Toss and turn. The alarm rings and instead of feeling refreshed and ready for the day, you’re in a fog. One out of three people have trouble falling asleep or staying asleep at some point in their lives, according to estimates. This condition, technically termed insomnia, may last for days, weeks, months, or years, and can take a large toll. Individuals with insomnia report symptoms that include fatigue, decreased alertness, irritability, depressed mood, impaired memory, poor concentration, and problems in their work and social life. In the past, the biological underpinnings of sleep were undefined, which hampered the development of treatments that could improve the nights and days of those with insomnia. Now, recent discoveries are lifting this roadblock. Scientists have identified several important components in the body and brain’s sleep-wake system that appear to be prime targets for drug development. This advance is leading to: A better understanding of the biology behind body rhythms and sleep. Improved treatments for troubled sleepers that unlike current medications could tap into specific internal sleep mechanisms. Today’s prescription medications for insomnia target the function of an important brain chemical, GABA, and quiet general brain activity to induce sleep. These drugs are considered safe and effective, but despite their success, they can have a downside. The medications’ widespread actions in the brain, for example, may also trigger unwanted effects, like memory problems. Copyright © 2004 Society for Neuroscience

Keyword: Sleep
Link ID: 6186 - Posted: 06.24.2010