Scientists have shown how it may be possible to use the body's own natural stress hormone to soothe the agonies of post-traumatic stress disorder. A team at the University of Texas discovered mice were less agitated by the memory of an electric shock after being given shots of corticosterone. The researchers believe the hormone works by creating new memories to compete with those causing anxiety. Tests are now underway to see if similar hormone shots can help humans. The research appears online in the Journal of Neuroscience. Days after experiencing a traumatic event - a mild electrical shock - mice in the study still showed a fearful response when re-exposed to the place where it happened, a condition that could be a model for post-traumatic stress disorder in humans. But mice receiving the corticosterone shot at the time they "relived" the event experienced a significant drop in that fear. Lead researcher Dr Craig Powell said: "Corticosterone appears to enhance new memories that compete with the fearful memory, thereby decreasing its negative emotional significance." His colleague, Dr Jacqueline Blundell, said: "The natural release of stress hormones during recall of a fearful memory may be a natural mechanism to decrease the negative emotional aspects of the memory. Conversely, patients with post-traumatic stress disorder have blunted stress hormone responses and thus may not decrease fearful memories normally over time." (C)BBC

Keyword: Stress; Learning & Memory
Link ID: 9375 - Posted: 09.21.2006

By Rick Weiss Researchers will report today that cells grown from human embryonic stem cells slowed vision loss when injected into the eyes of rats with a disease similar to macular degeneration, the leading cause of blindness in people older than 55. The experiments do not prove that the cells, obtained through the destruction of human embryos, will work in people. But by showing that the cells have the potential to fill in for failing cells in the retina, experts said, the work may help justify trying the technique in humans. Raymond D. Lund, then at the University of Utah's John A. Moran Eye Center in Salt Lake City, and Robert Lanza of Advanced Cell Technology Inc. (ACT) in Worcester, Mass., started by developing a reliable method for turning embryonic stem cells into retinal pigment epithelium cells, which nourish the light-sensitive "photoreceptor" cells in the eye. In macular degeneration, the pigment cells gradually disappear. The researchers achieved the transformation in all 18 stem cell lines they worked with -- including some provided by the National Institutes of Health and others developed privately at Harvard University and at ACT -- proving that their approach can consistently produce the crucial pigment cells. Then they injected the cells, about 20,000 per eye, into the retinas of 14 rats with a genetic disease similar to macular degeneration. Eight control rats received eye injections without any cells. © 2006 The Washington Post Company

Keyword: Vision; Stem Cells
Link ID: 9374 - Posted: 06.24.2010

Even the tiny, mild-mannered fruit fly can be a little mean sometimes – especially when there’s a choice bit of rotten fruit to fight over. And, like people, some flies have shorter tempers than others. Researchers in the North Carolina Sate University genetics department have identified a suite of genes that affect aggression in the fruit fly Drosophila melanogaster, pointing to new mechanisms that could contribute to abnormal aggression in humans and other animals. The study, led by doctoral student Alexis Edwards in the laboratory of Dr. Trudy Mackay, William Neal Reynolds Professor of Genetics, appears online in PloS Genetics. Feisty flies themselves may not be very scary, but their genes and biochemistry have more in common with those of humans than the casual observer might suspect, and geneticists can subject flies to experiments that simply can’t be done on higher organisms. To measure aggression, the researchers starved male flies for an hour and a half, then gave them a small food droplet and watched them duke it out, counting the number of times a focal fly would chase, kick, box, or flick his wings at other flies.

Keyword: Aggression; Genes & Behavior
Link ID: 9373 - Posted: 06.24.2010

An enzyme found naturally in the brain snips apart the protein that forms the sludge called amyloid plaque that is one of the hallmarks of Alzheimer's disease (AD), researchers have found. They said their findings in mice suggest that the protein, called Cathepsin B (CatB), is a key part of a protective mechanism that may fail in some forms of AD. Also, they said their findings suggest that drugs to enhance CatB activity could break down amyloid deposits, counteracting one of the central pathologies of AD. Li Gan and colleagues published their findings in the September 21, 2006, issue of the journal Neuron, published by Cell Press. Their experiments were prompted by previous studies showing that the cysteine protease CatB--an enzyme that snips apart proteins--closely associated with the amyloid-ß (Aß) protein that forms the amyloid plaques, a hallmark of AD. However, those studies had not determined whether CatB was "good" or "bad"--that is, whether it acted to produce Aß from a longer protein, called amyloid precursor protein (APP), or whether it broke down Aß. In their experiments, Gan and colleagues determined that CatB was the latter--breaking down Aß, apparently to enable other enzymes to further degrade the protein for the cell's protein "garbage deposal" system.

Keyword: Alzheimers
Link ID: 9372 - Posted: 09.21.2006

Daily life requires that people cope with distracting emotions--from the basketball player who must make a crucial shot amidst a screaming crowd, to a salesman under pressure delivering an important pitch to a client. Researchers have now discovered that the brain is able to prevent emotions from interfering with mental functioning by having a specific "executive processing" area of the cortex inhibit activity of the emotion-processing region. The findings also offer insight into how sufferers of post-traumatic stress disorder (PTSD) or depression are unable to control emotional intrusion into their thoughts, said the researchers, Amit Etkin, Joy Hirsch, and colleagues, who reported the discovery. They published their findings in the September 21, 2006, issue of the journal Neuron, published by Cell Press. Their studies were based on previous findings that specific parts of an area of the brain called the anterior cingulate cortex (ACC)--a center for so-called "executive" control of neural processing--are connected to the amygdala. The amygdala is the brain's major center for processing emotional events. The experimental challenge for Etkin, Hirsch, and colleagues was to determine whether this region of the ACC was responsible merely for "monitoring" conflict between cognitive and emotional processing or for actively "resolving" that conflict.

Keyword: Emotions
Link ID: 9371 - Posted: 09.21.2006

Rex Dalton The 3.3-million-year-old bones of a female toddler from Ethiopia are telling scientists a story about the route human ancestors took from the trees to the ground. In today's issue of Nature, an Ethiopian-led international team reports the discovery of a juvenile skeleton of the species commonly known as 'Lucy', or Australopithecus afarensis.1,2 The researchers have named her Selam, after an Ethiopian word for 'peace'. The specimen, which is the oldest and most complete juvenile of a human relative ever found, has features that stand as striking examples of part-way evolution between primitive apes and modern humans. Although many other samples of A. afarensis have been found before, this is the first one reported to come complete with a whole shoulder-blade bone (scapula). In modern humans the scapula has a ridge running horizontally across the top of the bone; in apes the scapula's ridge reaches further down the back, where it can help to throw more muscle into arm action, as would be needed to swing from trees. In the young A. afarensis, the scapula looks to be part-way between. "The animal was losing its capacity to be arboreal — heading right toward being human," says anthropologist Owen Lovejoy of Kent State University in Ohio. ©2006 Nature Publishing Group

Keyword: Evolution
Link ID: 9370 - Posted: 06.24.2010

NORTH GRAFTON, MASS., – In the October 2006 issue of the journal Endocrinology, a collaborative research study by scientists at Cummings School of Veterinary Medicine at Tufts University and the University of Otago Medical School in Dunedin, New Zealand, shows that pregnancy and lactation in rodents produce long-term changes in hormone receptor actions in a mother's brain that may affect maternal behavior as well as her response to stress. "It appears that hormonal changes occurring in rats after they nurse their pups may bring about endocrine and neuroendocrine changes that help produce better mothering skills with each pregnancy and reduce the mother's anxiety levels as she matures," said Robert S. Bridges, PhD, the senior author of this paper and head of the reproductive biology section at Tufts' Cummings School of Veterinary Medicine. In this study, female rats that had undergone a single pregnancy and nursed their offspring displayed higher levels of prolactin hormone receptor activity in the brain, as well as a greater receptor response when treated with prolactin weeks following the last contact with their young. Prolactin is produced by the pituitary gland and plays an established role in a range of reproductive functions, including milk production. The present study is the first to demonstrate long-term changes in the prolactin neural system, a system that Bridges' research group previously identified as crucial for stimulating the establishment of maternal behavior.

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 9369 - Posted: 06.24.2010

Michael Hopkin Simple stimulation of the brain can cause the mind to play complex and creepy tricks on itself, neurologists have discovered. They found that, by inserting electrodes into a specific part of the brain, they could induce a patient to sense that an illusory 'shadow person' was lurking behind her and mimicking her movements. Doctors treating the patient, a 22-year-old woman with epilepsy, found that when they stimulated a brain region called the left temporoparietal junction, the patient sensed the presence of a sinister figure behind her who copied her actions. They suspect that the effect is due to the mind projecting its own movements onto a phantom figure conjured up by the brain, an effect that is seen in some patients with serious psychiatric conditions. "It was quite astonishing — she definitely realized the 'person' was taking the same posture as she did, but she didn't make the connection," says Olaf Blanke of the École Polytechnique Fédérale de Lausanne in Switzerland, who led the research. "To her it remained a different person, an alien — exactly what you find in schizophrenics." The patient had no history of psychiatric problems. So the results suggest that this type of illusion, despite being an apparently complex psychiatric symptom, can be caused by a very simple switch in the brain. The mechanism might help to explain schizophrenic feelings such as paranoia, alien control, and the notion that parts of one's body belong to somebody else. ©2006 Nature Publishing Group

Keyword: Emotions; Epilepsy
Link ID: 9368 - Posted: 06.24.2010

Phil McKenna What do you do when your only means of attracting members of the opposite sex also puts your life in jeopardy? For field crickets on the Hawaiian island of Kauai, shutting up seems to work. According to a new study, rapid evolution in the Kauain population of the oceanic field cricket Teleogryllus oceanicus has rendered nine-tenths of the males there incapable of producing their iconic night-time call. The genetic mutation, which changes the shape of the male’s wing to make it silent, means the crickets are better adapted to avoid a deadly parasite. The finding dumbfounded biologist Marlene Zuk, at the University of California in Riverside, US, who first thought the dwindling population of crickets she was studying had gone extinct when she no longer heard their calls. “If you’re a cricket and you’re a male, your life is defined by calling,” Zuk explains. “How are you going to find a female, and once you do, how are you going to get her to mate with you without your call?” Zuk found that the quiet crickets maintained their reproductive chances by congregating near to the few remaining male crickets that are still capable of calling. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Evolution
Link ID: 9367 - Posted: 06.24.2010

Vitamin shots may help protect multiple sclerosis patients from severe long-term disability, a study suggests. Currently, there is no effective treatment for the chronic progressive phase of MS, when serious disability is most likely to appear. Researchers cut the risk of nerve degeneration in mice with MS-type symptoms by giving them a form of vitamin B3 called nicotinamide. The Children's Hospital Boston study appears in the Journal of Neuroscience. MS, which affects about 85,000 people in the UK, is a disease of the central nervous system. It causes the break down of the myelin sheath, a fatty protein, which coats nerve fibres, disrupting the ability to conduct electrical impulses to and from the brain. Many patients develop a form of the disease called relapsing-remitting MS, in which bouts of illness are followed by complete or partial recovery. In this early phase anti-inflammatory drugs can help. But eventually patients can enter the chronic progressive phase, for which there is no good treatment. The Boston team worked on mice with an MS-like disease called experimental autoimmune encephalitis (EAE). They found that daily nicotinamide shots protected the animals' nerve cells from myelin loss, and stabilised the condition of those cells that had already been affected. The greater the dose of nicotinamide, the greater the protective effect. Rating disability on a scale of one to five, mice receiving the highest doses of nicotinamide scored between one and two, while animals who received no shots at all scored between three and four. (C)BBC

Keyword: Muscles
Link ID: 9366 - Posted: 09.20.2006

By JANE E. BRODY For an older woman I know who was suffering from “implacable depression” that refused to yield to any medications, electroconvulsive therapy — popularly called shock therapy — was a lifesaver. And Kitty Dukakis, wife of the former governor of Massachusetts and 1988 Democratic presidential nominee, says ECT, as doctors call it, gave her back her life, which had been rendered nearly unlivable by unrelenting despair and the alcohol she used to assuage it. Neither woman has experienced the most common side effect of ECT: memory disruption, though Mrs. Dukakis recalls nothing of a five-day trip to Paris she took after her treatment. The television host Dick Cavett, who also had the treatment, wrote in People magazine, “In my case, ECT was miraculous.” Mr. Cavett added, “It was like a magic wand.” But for a man I know who was suicidally depressed and given ECT as a last resort, it did nothing to relieve his depression but destroyed some of his long-term memory. Such differences in effectiveness and side effects are not unusual in medicine and psychiatry, and they are not played down in a new book called “Shock,” which Mrs. Dukakis wrote with Larry Tye, a former Boston Globe reporter. The book, in which Mrs. Dukakis details her experience with depression and ECT, explores the history, effectiveness and downsides of this nearly 70-year-old treatment, a remedy that has been repeatedly portrayed in film and literature as barbaric, inhuman, even torturous. Copyright 2006 The New York Times Company

Keyword: Depression
Link ID: 9365 - Posted: 06.24.2010

Early to bed and early to rise may be a prescription for prosperity, but for some morning larks, it's an unfortunate condition written in their genes. These people suffer from familial advanced sleep phase syndrome (FASPS), a rare condition in which people hit the hay and wake up about four hours before everyone else. A simple expulsion of protein from the cell nucleus seems to be at the root of the syndrome, report researchers who studied the way that a previously identified mutant protein behaved in cultured human skin cells. The circadian clock is our body's inborn tool for keeping us on a roughly 24-hour schedule, sleeping and eating at regular intervals, but it can go awry. In many of those with FASPS, researchers had identified a mutation in a protein called PERIOD2. Some hypothesized that the mutant protein's effects arise from the lack of a key phosphate group, but nobody had identified a mechanism, says circadian researcher Achim Kramer of Charité Universitätsmedizin Berlin. Proteins of PERIOD2's family are thought to be more stable when studded with fewer phosphates, but Kramer and co-workers discovered that in this case the opposite is true. The team's research, published online September 18 in Genes and Development, found that the mutant protein degrades more than twice as fast, apparently because it is quickly transported from the nucleus to the cytoplasm, which is rife with protein-digesting enzymes. "Usually the protein is made in the cytosol, and then it goes into the nucleus and inhibits its own synthesis," Kramer explains. The inhibition erodes as the protein is pumped back outside the nucleus. © 1996-2006 Scientific American, Inc.

Keyword: Biological Rhythms; Genes & Behavior
Link ID: 9364 - Posted: 06.24.2010

After Susan Zilber's father died from Alzheimer's disease she wanted to know if she'd share his fate. "Information is key to figuring out how you're going to deal with something," she says. "That's part of who I am, and I think that I'd be able to deal with it. I'd rather know than not know." The problem is, there isn't a single test for Alzheimer's. Now, researchers have developed new software, called HipMask, that can potentially assess a person's risk for cognitive impairment by scanning of a tiny brain area called the hippocampus, which is known to be affected in the early stages of Alzheimer's. When applied to patient PET and MRI scans taken over the course of a longitudinal study of Alzheimer's, the software proved to be 85 percent accurate in predicting who would get the disease nine years before patients showed symptoms. "What we are trying to do is to find the measure that would predict decline from normal aging to Alzheimer's disease," explains Lisa Mosconi, a brain researcher at New York University School of Medicine's Center for Brain Health. "It looks like the hippocampus is particularly involved in early Alzheimer's disease, so by studying how the hippocampus [is working] in Alzheimer's patients — or in Alzheimer's patients it's actually not working — we can probably find a predictor for Alzheimer's disease." © ScienCentral, 2000-2006.

Keyword: Alzheimers; Brain imaging
Link ID: 9363 - Posted: 06.24.2010

A drug commonly used to treat severe acne can lead to depressive behaviour in mice, according to research published in the journal Neuropsychopharmacology. Since the drug’s introduction in the early 1980s there have been controversial reports of depression and suicidal behaviour that may have occurred in some people taking Roaccutane (Accutane in the US). This has led to the drug’s manufacturers, Roche, including a warning in the product information that taking the medication may cause depression, psychosis and suicidal behaviour. However, the chemical mechanism by which this might happen has never been established. In new independent research, scientists at the universities of Bath and Texas at Austin gave Roaccutane to mice over a period of six weeks, and then monitored the rodents’ behaviour. They found that whilst there was no change in the physical abilities of the mice, the rodents spent significantly more time immobile in a range of laboratory assessments designed to test their stress responsiveness – suggesting that administration of Roaccutane increases depression-related behaviour in mice. comms@bath.ac.uk © 2004

Keyword: Depression
Link ID: 9362 - Posted: 06.24.2010

Roxanne Khamsi Birdsongs are so distinctive they are often used by ornithologists to identify individual birds. Now a novel study shows that birds are not "pre-programmed" to sing their song – rather, birds listen closely to their tune to keep their songs note perfect. The same mechanism may operate in humans, perhaps shedding light on speech disorders, the researchers say. Songbirds do not start out life as virtuosos: they often begin by ‘babbling’ random pitches and then advance to sing sophisticated tunes with the help of a tutor. Once they develop their own particular melody, they use it to announce territorial claims or to attract a mate. The slight variations in the song identify one bird from another, so birds take great pains to preserve their unique tune throughout life. To establish how birds keep tabs on their singing, scientists have conducted experiments that involved disabling the birds’ ability to hear by removing a collection of sensory cells known as the cochlea. Over time, each animal produced songs that diverged further and further from its particular identifying tune. But an operation that leaves birds deaf could have other unintended cognitive effects that affect song production, argues Jon Sakata at the University of California in San Francisco, US. He and his colleague, Michael Brainard, set up an experiment that disrupted the hearing of the birds without an invasive procedure. © Copyright Reed Business Information Ltd.

Keyword: Animal Communication; Language
Link ID: 9361 - Posted: 06.24.2010

By Sandra G. Boodman Motherhood and depression share a long common border, author Tracy Thompson observes in "The Ghost in the House" (HarperCollins, $24.95), her exploration of the often-overlooked mental health problem. The book blends memoir with research on the topic. Thompson's focus is not the more-familiar postpartum form that can follow the birth of a baby, but the longer-term illness that affects an estimated 12 million American women, many of them diagnosed in the prime childbearing years between 25 and 44. In Thompson's view, unrealistic expectations about motherhood may be increasing the risk of depression in women who feel they can't measure up. A former Washington Post reporter who chronicled her battle with suicidal depression in her 1995 book "The Beast," Thompson explores the legacy of an illness that is often passed from grandmother to mother to daughter. She discusses ways the intergenerational link might be broken, based on insights gleaned from her own history and interviews with some of the 400 mothers whose accounts of depression she collected over several years. Following are excerpts from a recent question-and-answer session with the author: What do you mean by maternal depression? Maternal depression, the way I define it, is depression that is created or exacerbated by the stresses of being a mother in this culture at this time. It can be transmitted from mother to child via genetics, environment or through learned behavior -- or more likely a combination of all three things. It's depression as it intersects with motherhood, with the lifetime job of rearing a child. © 2006 The Washington Post Company

Keyword: Depression; Genes & Behavior
Link ID: 9360 - Posted: 06.24.2010

By BENEDICT CAREY In the hour before he was killed, on Sunday, Sept. 3, Dr. Wayne S. Fenton, a prominent schizophrenia specialist, was helping his wife clear the gutters of their suburban Washington house. He was steadying the ladder, asking her to please stop showering debris on his clean shirt; he had just made an appointment to see a patient and wanted to look presentable. She said she would be happy to go along, to help control the patient. It was a running joke between them. For in this part of the country, Dr. Fenton was the therapist of last resort, the one who could settle down and get through to the most severely psychotic, resistant patients, seemingly by sheer force of sympathy and good will. An associate director at the National Institute of Mental Health, he met with patients on weekends, sometimes late at night, at all hours. “Absolutely the most nonthreatening person you ever, ever met,” his wife, Nancy Fenton, said in an interview last week. At 4:52 p.m. that Sunday, the Montgomery County police found the 53-year-old psychiatrist dead in his small office, a few minutes’ drive from his house. They soon tracked down the patient he had agreed to meet that afternoon, Vitali A. Davydov, 19, of North Potomac, who admitted he had beaten the doctor with his fists, according to charging documents. When the young man left the office, “Dr. Fenton was on the ground, bleeding from the face,” the documents said. Copyright 2006 The New York Times Company

Keyword: Schizophrenia
Link ID: 9359 - Posted: 06.24.2010

In their hunt for genes and proteins that explain how animals discern bitter from sweet, a team of Johns Hopkins researchers began by testing whether mutant fruit flies prefer eating sugar over sugar laced with caffeine. Using a simple behavioral test, the researchers discovered that a single protein missing from the fly-equivalent of our taste buds caused them to ignore caffeine's taste and consume the caffeine as if it were not there. "No, you won't see jittery Drosophila flitting past your bananas to slurp your morning java anytime soon," says Craig Montell, Ph.D., a professor of biological chemistry in the Institute of Basic Biomedical Sciences at Hopkins. "The bottom line is that our mutant flies willingly drink caffeine-laced liquids and foods because they can't taste its bitterness -- their taste receptor cells don't detect it." The Hopkins flies, genetically mutated to lack a certain taste receptor protein, have been the focus of studies to sort out how animals taste and why we like the taste of some things but are turned off by the taste of others. By color-coding sweet and bitter substances eaten by fruit flies and examining the coloring that shows up in their translucent bellies, the Hopkins team hoped to learn whether flies missing a specific "taste-receptor" protein changed their taste preferences.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 9358 - Posted: 09.19.2006

By Rhitu Chatterjee When her nest is invaded by bloodsucking mites, the female house finch juggles the birth order of her future offspring. She first lays eggs that will bear daughters--which tend to be hardier--and saves the eggs of her more sensitive sons for last. The strategy ensures that vulnerable male chicks spend less time with the mites and may help explain why the house finch has been so successful in adapting to new environments. The house finch (Carpodacus mexicanus) is the conquistador of the bird world. Confined to the western United States and Mexico until about 1940, the bird quickly set up shop around the country when a few individuals were set loose in New York. Each population has had to overcome the hardships of its new environment, and scientists have long suspected that the secret to the bird's success is an ability to adapt very quickly to small changes in its surroundings. To find how these birds fare in the face of an aggressive adversary, evolutionary biologist Alexander Badyaev and his colleagues at the University of Arizona in Tucson turned to a group of house finches that has lived in Arizona for hundreds of years. During the breeding season in late spring, the bloodsucking nest mite (Pellonyssus reedi) attacks mothers and chicks. As in most bird species, the male chicks are especially vulnerable to danger when born. © 2006 American Association for the Advancement of Science.

Keyword: Sexual Behavior; Evolution
Link ID: 9357 - Posted: 06.24.2010

Neuroscience is tackling a problem that obsessed Hamlet: What is the difference in our minds between talk and action? Less than you would expect, an international research group reports in the Sept. 19 issue of Current Biology. The brain's premotor cortex shows the same activity pattern when subjects observe an action as when they hear words describing the same action, the study's authors said. "If you hear the word 'grasp,' it's actually the premotor cortex that's active, not just a separate, abstract semantic area in the brain," said lead investigator Lisa Aziz-Zadeh, assistant professor of occupational sciences with a joint appointment in the Brain and Creativity Institute of the USC College of Letters, Arts and Sciences. The premotor cortex has long been identified as a center of activity for actions. The notion that it could also process verbal descriptions of those actions has met some resistance. "Neuroscience is coming around to this idea, but there hasn't been much data supporting it," Aziz-Zadeh said.

Keyword: Language
Link ID: 9356 - Posted: 09.19.2006