Human primitive spinal cord cells delayed symptoms and paralysis by a week when implanted in the spinal cord of rats destined to develop amyotrophic lateral sclerosis (ALS), or Lou Gehrig's disease, researchers from Johns Hopkins report. The human neuronal stem cells were obtained from embryos by scientists at biotech company Neurostem Inc., transferred to Hopkins and implanted into the lower part of the rats' spinal cords about a month before the animals usually develop muscle control problems characteristic of ALS. The treatment delayed the animals' death by 11 days. Research associate Leyan Xu, Ph.D., is scheduled to present the results Oct. 23 at the annual meeting of the Society for Neuroscience in San Diego. "This rat model of ALS progresses very rapidly -- within two or three weeks of symptoms appearing, the rats have to be euthanized -- so the delay we saw is quite significant," says the study's senior author, Vassilis Koliatsos, M.D., associate professor of pathology, neurology, neuroscience and psychiatry and behavioral sciences at Hopkins. "Our study is proof of principle, that neuronal stem cells do have potential in conditions caused by separation within the nervous system, whether by disease or injury."

Keyword: ALS-Lou Gehrig's Disease
Link ID: 6321 - Posted: 10.26.2004

By LINDA CARROLL Parents want their children to succeed. And these days, toy store shelves are filled with products with names like Baby Einstein and Brainy Baby. The toy manufacturers do not come out and say it, but the clear implication is that babies who play with these toys may score some extra I.Q. points and get an early start on the road to an Ivy League college. Attuned to the increasing awareness among parents that the first three years are critical developmentally, companies are increasingly positioning their products as vital to optimizing intellectual growth. Child development experts, however, have their doubts. No studies exist, they point out, to show that any of the toys or videos give children an intellectual edge over playmates who stick to old-fashioned building blocks and baby dolls. While researchers have found that some babies who are deprived of certain stimuli during the first years of life never completely recover, they have yet to demonstrate that increasing stimulation makes babies smarter. And some experts believe that the toys may even be detrimental to development because they lead children to focus on memorization rather than imagination and problem-solving abilities. Copyright 2004 The New York Times Company

Keyword: Development of the Brain; Intelligence
Link ID: 6320 - Posted: 10.26.2004

Cranking up female sex drive, it may have played an important role in early societies By Liz Brown Breastfeeding women and their babies may hold the secret to developing a drug that could increase female sex drive. American researchers at the University of Chicago in Illinois have found that women's sex drive increased up to 24% after being exposed to breastfeeding compounds for two months. "This is the first report in humans of a natural social chemosignal that increases sexual motivation," says Martha McClintock, lead researcher. Though not necessarily perceived as odors, chemosignals affect mood and menstrual cycles when absorbed through the nose. To conduct the study, the researchers recruited 26 breastfeeding women and asked them to wear pads in their nursing bras and underarms. The pads collected infant saliva, perspiration and sweat, and the scientists then cut them into pieces and froze them. Copyright © 2002-2004 Betterhumans

Keyword: Sexual Behavior; Chemical Senses (Smell & Taste)
Link ID: 6319 - Posted: 06.24.2010

Many children slink past bed times the way the craftiest of thieves slip by security—with careful preparation and flawless backup plans. But new research shows that sleep-deprived middle-schoolers experience significant decreases in self-esteem, increased instances of depression and significant dips in grades. Jean Rhodes, professor of psychology at the University of Massachusetts at Boston, studied sleep in nearly 2,500 Chicago school children, aged 11 to 14-years-old. She reported in the January/February issue of the journal Child Development that as various factors suck the sleep out of children, a host of negative side effects result. "The fewer hours of sleep that children got, the more depressed they were, the higher number of depressive symptoms [they had], and the lower their self-esteem and the lower their grades," Rhodes explains. Biologically, middle school marks a child’s second largest growth spurt, a leap that dwarfs even the elementary school years, Rhodes says. As children grow and learn to steer past the pitfalls of puberty, they also learn to shuffle schedules filled with more and more activities. "There’s an increased need for sleep, yet at the same time middle-schooler’s lives are really complicated," Rhodes says. "They’re IMing (instant messaging), there are earlier school start times, extra-curricular [activities]…and so we know that this is a period of an increased need for sleep that’s clashing with an increased need to be awake." © ScienCentral, 2000- 2004

Keyword: Sleep; Development of the Brain
Link ID: 6318 - Posted: 06.24.2010

University of Toronto researchers have shown that human retinal stem cells transplanted into the eyes of mice and chicks can successfully regenerate. The research, published in the Oct. 19 issue of The Proceedings of the National Academy of Sciences, documents the development of transplanted human retinal stem cells into light-sensing photoreceptor cells and retinal pigment epithelial (RPE) cells, the cells which bounce light and images back onto the retina. "We transplanted the cells early in the animals' development when all the nutrients and signals they needed for differentiation were still there," says lead author Brenda Coles, a U of T laboratory technician working under the supervision of Professor Derek van der Kooy in the Department of Medical Genetics and Microbiology. "When their eyes fully developed, the human cells survived, migrated into the sensory part of the eye and formed the correct cells." The research has implications for future treatment of degenerative eye diseases such as retinitis pigmentosa and macular degeneration but that's still a long way off, says Coles. She, van der Kooy and their colleagues are now exploring whether retinal stem cells from healthy mice continue to develop into photoreceptor cells and RPE cells when transplanted to mice with diseased eyes.

Keyword: Stem Cells; Vision
Link ID: 6317 - Posted: 10.26.2004

SAN DIEGO--Doctors who treat patients with posttraumatic stress disorder (PTSD) have long sought a therapy that would erase bad memories, or at least keep them in check. Preliminary research on rats and humans presented here 24 October at the meeting of the Society for Neuroscience suggests that a drug already in wide use for treating high blood pressure might have just that effect. The drug, propranolol, blocks certain receptors for the neurotransmitter norepinephrine and has already shown promise in small clinical trials for PTSD, apparently preventing the formation of traumatic memories. In those studies, emergency room patients given propranolol within a few hours after an accident had fewer symptoms of posttraumatic stress months later. That suggested that propranolol could act as a prophylactic. The new work hints that propranolol might also work on memories that have already formed. Jacek Dębiec, a neurobiologist at New York University, conditioned rats to fear a tone by pairing it with a mild shock. After training, the rats freeze up in anticipation when they hear the tone. The next day, Dębiec refreshed the rats' memory, exposing them again to the tone and shock. He then gave half of the animals an injection of propranolol. Two days later, untreated rats still remembered what the tone meant; upon hearing it, they froze about 70% of the time. But rats given propranolol froze only about half as often, indicating a weaker memory for the fearful association between sound and shock. Even when Dębiec waited 2 months before reactivating the memory and delivering propranolol, the drug had a similar effect, he reported at the meeting and in a paper published in the current issue of Neuroscience. Copyright © 2004 by the American Association for the Advancement of Science.

Keyword: Learning & Memory; Emotions
Link ID: 6316 - Posted: 06.24.2010

EUGENE, Ore. -- A trusted mental map of your surroundings turns out to be slightly misaligned, skewing your orientation. Your ability to control the direction in which you move is similarly compromised, although in a manner opposite the map's offset. Taken together, the errors cancel one another, and you end up exactly where you want to be. Contrary to the proverb, two wrongs do make a right. This exception is the rule when it comes to how our brain processes what our eyes see and where our body moves, according to a discovery by University of Oregon researchers Paul Dassonville and Jagdeep Kaur Bala that will appear in the November issue of the journal PLoS Biology. Their study, funded by the National Science Foundation, challenged a dominant theory of how the brain processes vision. The theory holds that information from the eyes separates into two distinct streams: one to simply represent where we see things in the environment, and another to guide the physical movements of our body within that environment. Both processes have been thought to depend largely on accessing distinct maps of the environment within the brain, representing objects from varying locations in our field of vision by systematically varying activity in corresponding regions of the brain.

Keyword: Vision
Link ID: 6315 - Posted: 10.26.2004

by Rita Suri, M.D., and Lori L. Altshuler, M.D. Lifetime prevalence rates of major depressive disorder (MDD) in women are estimated to be as high as 21% (Kessler et al., 1993; Weissman et al., 1993). The postpartum period in particular represents a time of increased vulnerability for women (Cox et al., 1993; O'Hara et al., 1990), though postpartum disorders are often under-recognized and undertreated. Pregnant women generally receive little education about the possibility of depression after delivery, and because symptoms of depression can overlap with common postpartum symptoms, they may go unrecognized. Women may also feel ashamed of having negative emotions at a time when they "should be joyful" and thus not seek professional help. The DSM-IV defines postpartum depression as a major depressive episode with an onset in the first four weeks following childbirth. Although epidemiologic studies vary in the time frame used to define the postpartum period, ranging from four weeks to six months after delivery, the period of increased risk seems to occur relatively close to delivery. A study by Cox et al. (1993) of 232 postpartum women found that rates of depression were threefold higher in the five weeks after giving birth, but comparable at six months postpartum, when compared to a similarly matched control group of women who had not had a baby within the last 12 months. Wisner et al. (2004a) found that in 51 nondepressed women with a history of postpartum depression, 21 women developed a recurrent postpartum episode when followed for the year after childbirth. Five (24%) of these women experienced depression in the first postpartum month. © 2004 Psychiatric Times. All rights reserved.

Keyword: Depression; Hormones & Behavior
Link ID: 6314 - Posted: 06.24.2010

by Leo Sher, M.D. Light therapy, in one form or another, has been used as a treatment for a number of conditions since ancient times. Nearly 2,000 years ago, Greco-Roman physicians were treating depression and lethargy with sunlight directed toward the eyes. During his Arctic expeditions in the 1890s, Frederick Cook, M.D., noticing the profound influences of light on the voyagers and Alaskan natives, described a syndrome characterized by depressed mood, fatigue, and loss of energy and sexual desire. In 1946, H. Marx reported the use of bright artificial light to treat four men who had become depressed during an Arctic winter. Contemporary light therapy involves daily scheduled exposure to bright artificial light (Lam et al., 1999b; Partonen, 2001; Rosenthal and Matthews, 1999). The term light therapy is used to differentiate light therapy for psychiatric disorders from phototherapy for other conditions, such as hyperbilirubinemia or psoriasis. Since the first study of light therapy in winter seasonal affective disorder (SAD) (Rosenthal et al., 1984), a syndrome in which depression developed during fall or winter and remitted the following spring or summer for at least two successive years, numerous studies have concluded that bright light therapy is an effective treatment for SAD (Lam et al., 1999b; Magnusson and Boivin, 2003; Oren and Rosenthal, 1992; Partonen, 2001). © 2004 Psychiatric Times. All rights reserved.

Keyword: Depression; Biological Rhythms
Link ID: 6313 - Posted: 06.24.2010

by Richard C. Shelton, M.D. Currently available antidepressant medications are effective for a large segment of the population with depression. However, recent data suggest that a sizable portion of patients with unipolar depression do not experience full therapeutic recovery. For example, Simon et al. (1999) found that only about half of depressed patients treated with antidepressants in a primary care setting achieve recovery over a two-year period. Since lack of full response is common, management strategies need to be established and implemented. Current approaches include: the use of combination antidepressant treatments (e.g., selective serotonin reuptake inhibitor and bupropion [Wellbutrin]), augmentation (e.g., the addition of lithium [Eskalith, Lithobid] or thyroid hormone to an antidepressant), the addition of psychotherapy or electroconvulsive therapy (Shelton, 2003, 1999). However, even with these approaches, a significant minority of patients do not experience a full therapeutic effect. Recently, novel antipsychotics have shown some promise for the management of depressive disorders. From a mechanistic standpoint, the pharmacological properties of at least some of these drugs predict antidepressant properties. Novel antipsychotics act, to varying degrees, on a variety of dopamine, serotonin (5HT), glutamate and other receptors. The antagonism of 5HT2A receptors is common among these drugs, and blockade of this subtype is seen with other antidepressant agents such as mirtazapine (Remeron) and nefazodone (Serzone). Blocking of 5HT2C receptors has also been shown to enhance release of frontal dopamine and norepinephrine, which is thought to be a key antidepressant property (Shelton, 2003; Zhang et al., 2000). © 2004 Psychiatric Times. All rights reserved.

Keyword: Depression
Link ID: 6312 - Posted: 06.24.2010

SAN DIEGO – Students, keep this in mind before that next major exam: Pre-test jitters make it easier to recall memorized facts, but that stress also makes it tough to solve more complex problems. Researchers at Ohio State University gave a battery of simple cognitive tests to 19 first-year medical students one to two days before a regular classroom exam – a period when they would be highly stressed. Students were also given a similar battery of tests a week after the exam, when things were less hectic. While pre-exam stress helped students accurately recall a list of memorized numbers, they did less well on the tests that required them to consider many possibilities in order to come up with a reasonable answer. A week after the exam, the opposite was true. "Other studies have suggested that elevated stress levels can actually improve some aspects of cognition, particularly working memory," said Jessa Alexander, a study co-author and a research assistant in neurology at Ohio State. "The results of the two problem-solving tests we administered suggested a decline in problem solving abilities that required flexible thinking."

Keyword: Learning & Memory; Stress
Link ID: 6311 - Posted: 06.24.2010

Using an animal model system, researchers have advanced our understanding of Fragile X Syndrome by successfully visualizing individual mutant neurons in an otherwise normal brain. They find that brain neurons that fail to express appropriate levels of Fragile X protein are structurally abnormal and make defective connections to other neurons. The work is reported by a team led by Kendal Broadie at Vanderbilt University. Fragile X Syndrome is the most common type of inherited mental retardation. Since the early 1990's, it has been known that the disease results from the loss of a single gene and, for the last several years, that the Fragile X gene product regulates the expression of other proteins. However, the link between this molecular function and the Fragile X brain defect has remained a mystery. Employing a fruit fly model of the disease, the researchers utilized a new technique that allows the generation of single mutant nerve cells that are marked by their expression of a glowing fluorescent protein, making these nerve cells distinctly visible in an otherwise normal brain. In their experiments, the researchers were able to observe mutant nerve cells that either completely lacked the Fragile X protein or overexpressed it, the fluorescent protein label allowing the entire architecture of these neurons to be visualized in the intact brain.

Keyword: Genes & Behavior
Link ID: 6310 - Posted: 10.26.2004

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