The world’s first brain prosthesis has passed the first stages of live testing. The microchip, designed to model a part of the brain called the hippocampus, has been used successfully to replace a neural circuit in slices of rat brain tissue kept alive in a dish. The prosthesis will soon be ready for testing in animals. The device could ultimately be used to replace damaged brain tissue which may have been destroyed in an accident, during a stroke, or by neurodegenerative conditions such as Alzheimer’s disease. It is the first attempt to replace central brain regions dealing with cognitive functions such as learning or speech. To achieve their result, Theodore Berger and his colleagues at the University of Southern California in Los Angeles, US, had to develop a system that would “read” real neural signals from healthy tissue, process them just as the lost brain tissue should, and pass on the resulting signals to the next brain area. The brain region they are trying to replace is the hippocampus, which is vital for forming memories. The hippocampus has a well-understood three-part circuit. It also has a regular repeating structure, so elements of all three parts of the hippocampal circuit can be kept in a fully functional state, even in small slices in a culture dish. © Copyright Reed Business Information Ltd.

Keyword: Learning & Memory
Link ID: 6309 - Posted: 06.24.2010

SAN DIEGO – Researchers at the OHSU Oregon National Primate Research Center (ONPRC) have identified a key gene that impacts the timing of puberty and can shorten the time span for reproduction. The research was led by Sergio Ojeda, Ph.D., head of the Division of Neuroscience and a senior scientist at ONPRC. The work will be presented at the Society for Neuroscience annual meeting on Oct 24, 2004 by Claudio Mastronardi, the lead author of the report. "Using a mouse model, our lab has determined that the absence in the brain's hypothalamus of a gene called TTF-1 causes a delay in the onset of female puberty," explained Ojeda. "This work is of particular interest to those investigating both the delay and early onset of puberty in young women. While there is no definitive information, recently a number of research papers have been published suggesting that young women are reaching puberty at an earlier age. Other research has suggested that if this is the case, it may be linked to the nation's obesity crisis." Prior to the research to be reported at the Society for Neuroscience meeting, Ojeda's group performed studies with rats showing that the TTF-1 gene is expressed in a discrete cellular subset of the hypothalamus during sexual development. Then, using a genome-wide approach, they determined that expression of the TTF-1 gene increases in the hypothalamus of nonhuman primates at the onset of puberty.

Keyword: Hormones & Behavior; Obesity
Link ID: 6308 - Posted: 06.24.2010

Regular exercise could halt Parkinson's disease, US researchers believe. In a study on rats, exercise prevented degeneration of nerve cells that are normally destroyed by the disease. The University of Pittsburgh researchers are now recruiting patients to see if regular exercise has the same effect in humans. They told a meeting of the Society of Neuroscience how exercise might stimulate key proteins vital for nerve cell survival. In Parkinson's disease, cells in the brain that contain a messenger called dopamine progressively die out. This means messages don't get through in the normal way, which causes the tell-tale signs of the disease such as uncontrollable tremors, slow movements and rigid limbs. There is some disagreement within the Parkinson's research community as to the benefits of intense exercise for people with PD. While none have reported harm caused by physical activity, some studies have shown no statistical positive influence of exercise. Dr Michael Zigmond and colleagues examined the brains of rats that had exercised for seven days before receiving a toxin that is known to induce a disease resembling Parkinson's in rodents. They compared these animals to rats that had not been exercised before receiving the toxin. Exercise appeared to protect the brain against Parkinson's-type damage. Fewer dopamine-containing nerve cells, or neurons, died in the exercised rats compared to the sedentary rats. The researchers believe exercise stimulates the production of proteins that are important for the survival of neurons. (C)BBC

Keyword: Parkinsons
Link ID: 6307 - Posted: 10.25.2004

By MARC SANTORA The disease's fatal grip on the brain seems to come out of nowhere, afflicting an otherwise healthy person and turning him into an incoherent muddle. In Ulster County in upstate New York, that was how death came to at least two people in the last year. The rare brain malady called Creutzfeldt-Jakob disease caused the death of one resident in November 2003 and of a second this fall. About one in a million people worldwide die from the mysterious disease each year, and there is no medical explanation for why the disease afflicts humans in its most common form. There has been a recent buzz in Ulster County about the strange illness, but only within the small circles of the victims' families. Then the community discovered that a 60-year-old woman had died in August from an illness that seemed similar to Creutzfeldt-Jakob disease. The woman's family did not allow an autopsy, so it cannot be determined if she had the disease. But after comparing notes, people found out that another person in nearby Dutchess County died of the disease this year. There have been other unusual deaths, including that of another woman in Ulster County, Colleen Staccio, 46, who died in August from a condition her doctors initially said was Creutzfeldt-Jakob disease but whose autopsy showed otherwise, and that of Richard Tobey, 59, who died of the disease two weeks ago. Copyright 2004 The New York Times Company

Keyword: Prions
Link ID: 6306 - Posted: 10.25.2004

By Norman M. Weinberger Music surrounds us–and we wouldn't have it any other way. An exhilarating orchestral crescendo can bring tears to our eyes and send shivers down our spines. Background swells add emotive punch to movies and TV shows. Organists at ballgames bring us together, cheering, to our feet. Parents croon soothingly to infants. And our fondness has deep roots: we have been making music since the dawn of culture. More than 30,000 years ago early humans were already playing bone flutes, percussive instruments and jaw harps--and all known societies throughout the world have had music. Indeed, our appreciation appears to be innate. Infants as young as two months will turn toward consonant, or pleasant, sounds and away from dissonant ones. And when a symphony's denouement gives delicious chills, the same kinds of pleasure centers of the brain light up as they do when eating chocolate, having sex or taking cocaine. Therein lies an intriguing biological mystery: Why is music--universally beloved and uniquely powerful in its ability to wring emotions--so pervasive and important to us? Could its emergence have enhanced human survival somehow, such as by aiding courtship, as Geoffrey F. Miller of the University of New Mexico has proposed? Or did it originally help us by promoting social cohesion in groups that had grown too large for grooming, as suggested by Robin M. Dunbar of the University of Liverpool? On the other hand, to use the words of Harvard University's Steven Pinker, is music just "auditory cheesecake"--a happy accident of evolution that happens to tickle the brain's fancy? © 1996-2004 Scientific American, Inc.

Keyword: Hearing
Link ID: 6305 - Posted: 06.24.2010

Washington -- Researchers at the Boston Veterans Affairs Health Care System – Brockton Division, Harvard Medical School, and the University of Massachusetts-Boston are using new imaging technology to gather valuable information about the brains of people with schizophrenia. This new variety of magnetic resonance imaging (MRI) is called diffusion tensor imaging (DTI). Using DTI on patients with schizophrenia, neuropsychologists have related smaller sizes in two distinct webs of brain fibers to two distinct types of cognitive malfunction. The findings appear in the October issue of Neuropsychology, which is published by the American Psychological Association (APA). Diffusion tensor imaging (DTI) uses a regular MRI machine to analyze the movement of water molecules in and around the fibers that connect different parts of the brain. Neuroscientists use DTI to track indicators of brain "connectivity" – factors such as the number, thickness, density and arrangement of axons (the hair-like extensions of neurons, which send messages to other neurons) and thickness of the insulating/conducting fatty myelin sheath in which they are embedded. If weaker structural integrity reduces connectivity, lead author Paul Nestor, PhD, says it may mean that, "different brain areas do not communicate as well – with less synchrony or harmony, akin to an orchestra or band playing out of synch."

Keyword: Schizophrenia; Brain imaging
Link ID: 6304 - Posted: 06.24.2010

SAN DIEGO-- A repetitive drop in blood oxygen levels in newborn rats, similar to that caused by apnea (brief pauses in breathing) in some human infants, is followed by a long-lasting reduction in the release of the brain neurotransmitter dopamine, according to an Emory University research study. Because dopamine promotes attention, learning, memory and a variety of higher cognitive functions, the researchers believe repetitive apnea during neonatal development may be one factor leading to the development of attention deficit hyperactivity disorder (ADHD). This research will be reported at the Society for Neuroscience annual meeting in San Diego on October 24 by Glenda Keating, PhD, and Michael Decker, PhD, of the Department of Neurology at Emory University's School of Medicine. The research was funded by the National Heart Lung and Blood Institute and conducted by the Program in Sleep Medicine and the Department of Neurology at Emory University. Apnea of prematurity occurs in up to 85 percent of all prematurely born human infants, and obstructive sleep apnea occurs in 3 to 27 percent of all children. Data from previous studies suggests that diminished release of brain dopamine may be responsible for behaviors such as impulsiveness and distractibility, reduced self control, and impaired learning, which are hallmark traits associated with ADHD. Previous studies in Dr. Decker's laboratory at Emory have shown that newborn rats who experience repetitive drops in blood oxygen levels go on to develop behavioral traits similar to those seen in humans with ADHD. This is the first time, however, that researchers have linked repetitive reductions in blood oxygen levels during a period of critical brain development to long-lasting deficiencies in release of dopamine specifically within the striatum, which is one of the brain regions important in modulating behavior, learning and memory.

Keyword: ADHD
Link ID: 6303 - Posted: 10.25.2004

The weird and wonderful duck-billed platypus just got even more weird and more wonderful. Platypuses are famous for laying eggs yet producing milk, having a bird-like bill and a skeleton with reptilian features. Now it turns out that the mammal has an equally eye-catching way of deciding its sex, according to a study by Frank Grützner and Jenny Graves at the Australian National University in Canberra, and colleagues. In most mammals, including humans, sex is decided by the X and Y chromosomes: two Xs create a female, while XY creates a male. In birds, the system is similar: ZW makes for a female, while ZZ makes for a male. But in platypuses, XXXXXXXXXX creates a female, while XYXYXYXYXY creates a male. In other words, rather than a single chromosome pair, platypuses have ten-chromosome chains that determine their sex. The researchers worked out the make-up of platypus sex chromosomes by using fluorescent markers to stain chromosomes in platypus cells before examining them under a microscope. The researchers also found that when sperm is produced by male platypuses, the chromosomes in the chain are precisely distributed to form XXXXX-bearing sperm and YYYYY-bearing sperm. When an XXXXX-bearing sperm fertilises an egg it produces a female platypus. YYYYY-bearing sperm would produce a male. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Evolution
Link ID: 6302 - Posted: 06.24.2010

St. Louis, -- Severe calorie restriction prevents certain aging-related changes in the brain, including the accumulation of free radicals and impairments in coordination and strength, according to a mouse study at Washington University School of Medicine in St. Louis. However, the dietary changes did not seem to prevent mice from developing some cognitive deficits associated with age, such as declines in memory. The study will be presented at 3 p.m. PT on Sunday, Oct. 24 at Neuroscience 2004, the Society for Neuroscience's 34th Annual Meeting in San Diego. "Our findings help us understand the processes underlying both normal aging and calorie restriction benefits," says principal investigator Laura L. Dugan, M.D., associate professor of neurology, of medicine and of anatomy and neurobiology. "If some aspects of aging are influenced by free radical damage, we may be able to prevent or reverse these impairments." Though numerous studies have shown severe calorie restriction helps animals live longer and resist some effects of aging, scientists still do not know why. One theory suggests a restrictive diet decreases the effect of free radical damage.

Keyword: Alzheimers; Obesity
Link ID: 6301 - Posted: 10.25.2004

By Jennifer Viegas, Discovery News A University of Florida scientist has created a living "brain" of cultured rat cells that now controls an F-22 fighter jet flight simulator. Scientists say the research could lead to tiny, brain-controlled prosthetic devices and unmanned airplanes flown by living computers. And if scientists can decipher the ground rules of how such neural networks function, the research also may result in novel computing systems that could tackle dangerous search-and-rescue jobs and perform bomb damage assessment without endangering humans. Additionally, the interaction of the cells within the lab-assembled brain also may allow scientists to better understand how the human brain works. The data may one day enable researchers to determine causes and possible non-invasive cures for neural disorders, such as epilepsy. For the recent project, Thomas DeMarse, a University of Florida professor of biomedical engineering, placed an electrode grid at the bottom of a glass dish and then covered the grid with rat neurons. The cells initially resembled individual grains of sand in liquid, but they soon extended microscopic lines toward each other, gradually forming a neural network — a brain — that DeMarse says is a "living computational device." Copyright © 2004 Discovery Communications Inc.

Keyword: Robotics
Link ID: 6300 - Posted: 06.24.2010

COLUMBUS, Ohio – Inebriated bees could give researchers better insight into alcohol's effects on human behavior, a new study suggests. "Alcohol affects bees and humans in similar ways – it impairs motor functioning along with learning and memory processing," said Julie Mustard, a study co-author and a postdoctoral researcher in entomology at Ohio State University. Researchers gave honey bees various levels of ethanol, the intoxicating agent in liquor, and monitored the ensuing behavioral effects of the drink – specifically how much time the bees spent flying, walking, standing still, grooming and flat on their backs, so drunk they couldn't stand up. The researchers also measured the level of ethanol in the bees' hemolymph – the circulatory fluid of insects that's akin to blood. Not surprisingly, increasing ethanol consumption meant bees spent less time flying, walking and grooming, and more time upside down. The appearance of inebriation occured sooner for bees that were given a larger dose of ethanol. Also, blood ethanol levels increased with time and the amount of ethanol consumed.

Keyword: Drug Abuse
Link ID: 6299 - Posted: 06.24.2010

Treating children with anti-psychotic drugs may increase the risk of a condition which leads to diabetes and heart disease, research suggests. A team from Johns Hopkins University looked at 'atypical' antipsychotics, used to treat behavioural problems such as manic depression and schizophrenia. They found their use may trigger insulin resistance. The research was presented to a meeting of the American Academy of Child and Adolescent Psychiatry. Considerable weight gain is a common side effect of atypical antipsychotic medications - and is also one of the many factors that can contribute to insulin resistance. All six children on moderate or high doses of one of these drugs, and three of five children on low doses, had evidence of insulin resistance. This is a condition in which the body cannot properly use the insulin it produces. Lead researcher Dr Mark Riddle said: "The insulin resistance seen in these children was greater than what would be expected from weight gain alone, suggesting there is a factor distinct from excess weight that directly induces insulin resistance." (C)BBC

Keyword: Schizophrenia; Development of the Brain
Link ID: 6298 - Posted: 10.23.2004

New Haven, Conn.--Estrogen treatment had less beneficial effect on memory in female mice that raced on running wheels and played with other toys than in mice raised in non-stimulating environments, according to a Yale study published this month. "We saw no beneficial effect of estrogen in the animals in cognitively and physically stimulating environments (also known as enriched environments)," said Karyn Frick, assistant professor of psychology and principal investigator on the study. "This fits in nicely with human data and might help to explain why studies of hormone replacement therapy (HRT) do not show beneficial effects for all women. Most studies of HRT use very well-educated women. These results might spur researchers to include a broader population with a greater variation in education and socioeconomic status." All of the mice lived in standard housing conditions that contained other mice and no toys. However, enriched mice spent three hours each day in larger cages with running wheels, tubes, and other mouse toys. The toys were varied from day to day. At 10 weeks of age, the ovaries of the mice were removed to simulate the long-term estrogen losses seen in menopause. At six months of age, the mice were then treated with estrogen or a control substance and were tested in tasks measuring spatial memory and memory for objects.

Keyword: Hormones & Behavior; Learning & Memory
Link ID: 6297 - Posted: 10.23.2004

An international research team, led by scientists at the National Institute on Aging (NIA), has discovered a gene, which when mutated, causes Parkinson’s disease in some families. Although Parkinson’s disease is usually not inherited, the discovery of this gene and further study of how it works could open up new avenues of research for preventing or delaying the onset of the disease. In research, the study of rare familial forms of a disease has often led to major insights into the pathogenesis of more common forms. The finding was published online by Neuron on October 22, 2004. The collaborative work was spearheaded by Andrew Singleton, Ph.D., at the NIA, Jordi Perez-Tur of the Institut de Biomedicina de Valencia in Spain, and Nick W. Wood of the Institute of Neurology in London. The NIA is a part of the National Institutes of Health (NIH) at the U.S. Department of Health and Human Services. "Parkinson's disease has a devastating impact upon individuals," says Elias A. Zerhouni, M.D., Director of the NIH. "This finding provides scientists with important new information about genetic mutations that underlie this disease, giving us new understanding about molecular mechanisms. Ultimately, this research will help in the development of targeted interventions that could actually alter the course of this disabling disease."

Keyword: Parkinsons; Genes & Behavior
Link ID: 6296 - Posted: 06.24.2010

By Peter Mombaerts Rarely do scientific studies claim that something is not the case. Rarer still do negative results appear in top-tier journals. Yet two recent papers in Nature describe what olfactory sensory neurons do not do.1,2 The olfactory system is often compared to the immune system. The key cell types in each system, the olfactory sensory neuron (OSN) and the lymphocyte, can detect a wide variety of chemicals, both natural and synthetic. Chemical recognition by these cells is specific and sensitive, so many odorant receptors (ORs)3 and antigen receptors are needed to cover the spectrum of chemical structures. It has been well established that each B or T lymphocyte expresses a single antigen receptor--an antibody or T-cell receptor. Analogously, each vertebrate OSN is thought to express a single OR gene. Lymphocytes restrict antigen receptor gene expression by genome modification, and many believed that OSNs did likewise. Now we1 and others2 claim that OR genes do not undergo irreversible genomic alterations in OSNs. With this hypothesis disproved, we may need to reassess the dogma that a single OSN expresses just one OR gene. © 2004, The Scientist LLC, All rights reserved.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 6295 - Posted: 06.24.2010

By David Secko A brain without glutamate, the major excitatory neurotransmitter in mammals, is quite literally unthinkable. Yet, knockout mice lacking the crucial vesicular glutamate transporter, VGLUT1, can live for up to a few months. This unexpected finding has enabled two research groups to investigate the function of VGLUT1. With potential links to learning and memory, as well as neurological diseases such as epilepsy, approaching glutamate transmission through the protein believed to load it into vesicles provides a useful starting point. "It is, so to speak, the fuel needed to make vesicle release recognized," says Christian Rosenmund at Baylor College of Medicine, Houston. Mice lacking this glutamate transporter survive, likely through the action of the isoform VGLUT2, but soon suffer from progressive neurological decline, blindness, poor coordination, and ultimately death. While not all the results appear to match up, the knockouts are lending insight into vesicle loading and neural development. "The knockouts enabled us to compare the behavior of VGLUT1 and 2 synapses," says Robert Edwards, University of California, San Francisco. A vesicular glutamate transporter proved difficult to identify. But in 2000, Rosenmund, Edwards, and their respective colleagues independently realized that it had been masquerading as an inorganic phosphate transporter.1 Renamed VGLUT1, the protein could actively transport glutamate into synaptic vesicles using a proton electrochemical gradient. Soon after VGLUT1's identity materialized, two isoforms, VGLUT2 and VGLUT3, were found. © 2004, The Scientist LLC, All rights reserved.

Keyword: Learning & Memory
Link ID: 6294 - Posted: 06.24.2010

By Jill U. Adams Communication between neurons--the stuff of our senses, emotions, and memories, as well as motor and visceral control--relies on chemical messengers. Packaged into tiny membrane-enclosed vesicles, neurotransmitters are delivered when a nerve impulse induces exocytosis. In addition to delivering the message to the receiving neuron, neurotransmission results in changes to the sending neurons, which lose transmitter-loaded vesicles and grow larger as spent vesicles are incorporated into the plasma membrane. Synaptic vesicle recycling resolves both of these changes by pinching off new vesicles from the cell surface for reloading. Often overlooked as mere housekeeping, synaptic vesicle recycling is crucial to neuronal preparedness. The number of vesicles in the releasable pool must be maintained. With biophysical methods allowing study of single vesicle events even in small nerve terminals, recycling research is intensifying as scientists propose mechanisms by which membrane segments are retrieved for reuse. Stimulating much of the new work is the kiss-and-run hypothesis: A vesicle fuses with the cell surface just enough to allow neurotransmitters to flow into the synaptic cleft, and then pinches off to return to the intracellular vesicle pool. Just like the returnable glass soda bottles from yesteryear, the vesicle maintains its membrane shell and simply needs to be refilled. The classical pathway is more akin to melting down bottles for remanufacturing. Opened vesicle membranes collapse into the plasma membrane and their components move to an offsite recycling facility of sorts where sorting and endocytosis occur via clathrin- coated pits. © 2004, The Scientist LLC, All rights reserved.

Keyword: Drug Abuse
Link ID: 6293 - Posted: 06.24.2010

By Bruce Lieberman UNION-TRIBUNE STAFF WRITER University of California San Diego professor Mark Ellisman, shown in his office with an enlarged image of a cerebellum scan as a backdrop, is coordinating a nationwide effort to build a database on neuroanatomy and brain diseases. In a lab at UCSD, Don Cleveland works on Lou Gehrig's disease. Fred Gage, at the Salk Institute, looks at how the brain remodels and repairs itself. A few blocks north on Torrey Pines Road, Evan Snyder of The Burnham Institute studies how stem cells might someday replace nerve cells ravaged by Parkinson's disease. These scientists and many others have built San Diego into a world center for brain research. Tomorrow, they will be joined by an estimated 30,000 researchers gathering in San Diego for the 34th annual meeting of the Society for Neuroscience. The conference, which will continue through Wednesday, will profile the latest discoveries about how the brain develops, grows and ages; the biology behind depression, addiction and schizophrenia; the science of consciousness; what drives brain diseases; and many other topics. © Copyright 2004 Union-Tribune Publishing Co.

Keyword: Miscellaneous
Link ID: 6292 - Posted: 06.24.2010

Common prostate cancer therapy disrupts brain's hippocampal memory system PORTLAND, Ore. - Oregon Health & Science University researchers studying how testosterone deprivation affects verbal memory found that men undergoing the prostate cancer therapy forget things faster than their healthy counterparts. Scientists in the OHSU School of Medicine's departments of Behavioral Neuroscience and Medicine, and the OHSU Cancer Institute, in a study to be presented Sunday to the Society for Neuroscience in San Diego, found that word retention drops sharply after only two minutes among men undergoing testosterone deprivation therapy. However, initial learning of the words, or encoding, was the same for testosterone-deprived and healthy men, according to the study titled "Androgen ablation impairs hippocampal-dependent verbal memory processes." Men who have undergone testosterone deprivation "are able to encode these words well, and if I ask them immediately, they can recall them as easily as non-hormone-deprived men," said Joseph Bussiere, a graduate student in behavioral neuroscience and the study's lead author. "But after only two minutes, there's a marked drop-off. When you stretch the time between encoding and retrieval, that's where the problem lies." © 2001-2004, Oregon Health & Science University

Keyword: Learning & Memory; Hormones & Behavior
Link ID: 6291 - Posted: 06.24.2010

Researchers have produced strong evidence that older fathers are more likely to have children who develop schizophrenia. The finding adds weight to the theory that accumulating mutations in the sperm are to blame. Sweden's Karolinska Institute and Bristol University estimate older fathers could account for 710 cases in England and Wales in 2002. The study is published in the online edition of the British Medical Journal. The researchers analysed the medical records of over 700,000 people born between 1973 and 1980. They found that, even after taking into consideration other factors, people born to older fathers were at increased risk of developing schizophrenia. They calculated that overall 15.5% of cases of schizophrenia seen in the group may have been due to the patient having a father who was aged over 30 years at their birth. The association seemed to be relatively specific to schizophrenia compared with other related forms of psychosis. It was also stronger in those with no family history of the disorder. The researchers argue that the key is the accumulation of mutations in older fathers' sperm. It is known that spontaneous genetic errors are more likely to occur in sperm and egg cells produced by older people - a phenomenon known as age-related aneuploidy. In England and Wales the average paternal age has increased from 29.2 years in 1980 to 32.1 in 2002. (C)BBC

Keyword: Schizophrenia
Link ID: 6290 - Posted: 10.22.2004