Alison Preston Memory consolidation can occur at many organizational levels in the brain. Cellular and molecular changes typically take place within the first minutes or hours of learning and result in structural and functional changes to neurons (nerve cells) or sets of neurons. Systems-level consolidation, involving the reorganization of brain networks that handle the processing of individual memories, may then happen, but on a much slower time frame that can take several days or years. Memory does not refer to a single aspect of our experience but rather encompasses a myriad of learned information, such as knowing the identity of the 16th president of the United States, what we had for dinner last Tuesday or how to drive a car. The processes and brain regions involved in consolidation may vary depending on the particular characteristics of the memory to be formed. Let's consider the consolidation process that affects the category of declarative memory—that of general facts and specific events. This type of memory relies on the function of a brain region called the hippocampus and other surrounding medial temporal lobe structures. At the cellular level, memory is expressed as changes to the structure and function of neurons. For example, new synapses—the connections between cells through which they exchange information—can form to allow for communication between new networks of cells. Alternately, existing synapses can be strengthened to allow for increased sensitivity in the communication between two neurons. Consolidating such synaptic changes requires the synthesis of new RNA and proteins in the hippocampus, which transform temporary alterations in synaptic transmission into persistent modifications of synaptic architecture. © 1996-2007 Scientific American, Inc.

Keyword: Learning & Memory
Link ID: 10781 - Posted: 06.24.2010

Catherine Brahic Far from being lethargic and lazy creatures, crocodiles will travel hundreds of miles to return home, the first satellite-tracking experiment of the reptile has confirmed. Australian scientists tracked three saltwater crocodiles after moving them between 56 and 126 kilometres away from their home territory. The study confirms that the world's largest reptile has a remarkable homing instinct and will cover great distances in order to get home. It also suggests that airlifting problematic crocs to new areas may be ineffective at keeping them away. Aided by crocodile expert and TV presenter Steve Irwin, who died in September 2006, Craig Franklin of the University of Queensland and colleagues captured the three large male saltwater crocodiles (Crocodylus porosus) from coastal areas between August and September 2004. After fitting each with a satellite tracking device, the researchers airlifted each of the animals by helicopter to a new stretch of coastline either 56 km, 99 km or 126 km away. All three animals behaved in roughly the same way. After a few weeks of exploring their new habitats, each set off home, travelling around the coast back to their point of departure, taking between 5 and 20 days to get home. © Copyright Reed Business Information Ltd.

Keyword: Animal Migration
Link ID: 10780 - Posted: 06.24.2010

Scientists have discovered a link between a mutated gene and a protein found in dead brain cells of people who suffer from a form of dementia and other neurological disorders. The finding, reported in the Sep. 26, 2007, issue of the Journal of Neuroscience, demonstrates for the first time a pathological pathway that ultimately results in cell death related to frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS, also known as Lou Gehrig's disease). The discovery could eventually play a role in the design of new drug therapies. The study was funded by the National Institute on Aging (NIA) at the National Institutes of Health (NIH). Leonard Petrucelli, Ph.D., and Dennis W. Dickson, M.D, of the Mayo Clinic in Jacksonville, Fla., led the international team of scientists in the study supported by the Mayo Clinic Foundation. The study, in cell cultures, showed that a cell death pathway is involved. A cascade of events begins with a mutation in the gene progranulin (PGRN) located on chromosome 17. Normally, high levels of PGRN exist in a cell to promote cell growth and survival. But when progranulin gene mutations occur, low levels of PGRN result. The investigators showed that this causes a protein called TDP-43 to be cut into two fragments. These fragments then migrate from their usual location in the nucleus into the surrounding cytoplasm of the cell where they form inclusions, or insoluble clumps of protein. This abnormal process results in the neurodegeneration in people with FTD and ALS.

Keyword: Alzheimers; Apoptosis
Link ID: 10779 - Posted: 09.27.2007

When you have Tourette Syndrome, you get used to the physical and vocal tics that others often view as faux pas. I know, I have it. When I interviewed 14-year-old Andrew Youngen, who participated in a study designed to find out if the neurological disorder affects the brain in other ways, I began by asking him to tell me some things about himself for background. I wanted to see if he would mention his Tourette Syndrome in his description of himself. He didn't. He told me how he enjoys coin collecting, but in a way that I thought was pretty unique-- he makes sure to get one of those kitschy-touristy penny presses at every attraction he visits. But, while people with Tourette may not think of the neurological disorder as one of the most important parts of themselves, having it has made Andrew into a sort of ad-hoc Tourette ambassador. He does "in-service" visits to classrooms to explain that his sudden or repetitive motions and sounds are involuntary. "After we watch the video, I say in my own words what Tourette is and how it affects me, and I can't help anything about it… And then they usually have some questions, like, actually last year, I got a question, 'What can we do to help?'" "It was the first time I've ever gotten that, it was a very nice one," Andrew says. © ScienCentral, 2000-2007

Keyword: Tourettes
Link ID: 10778 - Posted: 06.24.2010

Katharine Sanderson How do migrating birds perceive which way is north? Research now points to the idea that they actually 'see' the Earth's magnetic fields, rather than feeling or sensing them in some other way. Previous work has suggested that the Earth's magnetic field might act on the sensitivity of a migratory bird's eye, so that sight might be involved in finding magnetic north. Now researchers have firmed that up with evidence that molecules in the eyes of migratory birds are connected to the part of the brain that guides their direction of flight. Dominik Heyers, at the University of Oldenburg, Germany, and colleagues injected migratory garden warblers (Sylvia borin) with a tracer capable of travelling along neuronal fibres along with nerve signals. They injected one tracer into the part of the forebrain known to be the only active area when birds orient themselves (known as Cluster N), and a different tracer into the retina. After a bird experienced a desire to migrate, both tracers ended up in the same place, the researchers report in the Public Library of Science One1 — a part of the thalamus responsible for vision. This anatomical link strongly supports the notion that the birds probably experience magnetic fields as a visual sensation, say the researchers. ©2007 Nature Publishing Group

Keyword: Animal Migration
Link ID: 10777 - Posted: 06.24.2010

Acupuncture - real or sham - is more effective at treating back pain than conventional therapies, research suggests. A German team found almost half the patients treated with acupuncture felt pain relief. But the Archives of Internal Medicine study also suggests fake acupuncture works nearly as well as the real thing. In contrast, only about a quarter who received drugs and other Western therapies felt better. The researchers, from the Ruhr University Bochum, say their findings suggest that the body may react positively to any thin needle prick - or that acupuncture may simply trigger a placebo effect. One theory is that pain messages to the brain can be blocked by competing stimuli. Researcher Dr Heinz Endres said: "Acupuncture represents a highly promising and effective treatment option for chronic back pain. "Patients experienced not only reduced pain intensity, but also reported improvements in the disability that often results from back pain and therefore in their quality of life." More than 1,100 patients took part in the study. They were given either conventional therapy, acupuncture or a sham version. Although needles were used in the sham therapy, they were not inserted as deeply as in standard acupuncture. Neither were they inserted at points thought key to producing a therapeutic effect, or manipulated and rotated once in position. After six months 47% of patients in the acupuncture group reported a significant improvement in pain symptoms, compared to 44% in the sham group, and just 27% in the group who received conventional therapy. (C)BBC

Keyword: Pain & Touch
Link ID: 10776 - Posted: 09.25.2007

They're embedded in everything from mattresses to insoles for shoes to wrist bands — but there is no definitive scientific evidence that static magnets can relieve chronic pain, researchers say. Products that incorporate static magnets are a multibillion-dollar business worldwide, and many chronic pain sufferers are drawn by the promise they hold for alleviating such nagging conditions as arthritis, fibromyalgia and low back discomfort. The theory from proponents is that a magnetic field increases blood flow, causing increased oxygen, nutrients, hormones and painkilling endorphins to be distributed to tissues in the affected area. 'There is no definite grounds of being absolutely sure that a magnet works or not.' —Dr. Max Pittler, researcherResearchers at the universities of Exeter and Plymouth in England decided to search the medical literature to determine whether there is any proof magnets can reduce pain. In their analysis of nine randomized trials comparing products containing magnets with those containing either no magnet or very weak ones, the researchers found that the data did not support the use of magnetic therapy for pain control. "There is no definite grounds of being absolutely sure that a magnet works or not," lead author Dr. Max Pittler, a complementary medicine specialist, said Monday. © CBC 2007

Keyword: Pain & Touch
Link ID: 10775 - Posted: 06.24.2010

If you want to have lots of kids, look for a Barry White instead of a Justin Timberlake. Men with a deep voices have more offspring, a new study suggests. Previous studies conducted by David Feinberg of McMaster University in Canada have shown that women are more attracted to men with deeper voices, judging them to be older, healthier and more masculine than their higher-pitched rivals. Men, on the other hand, go for women with higher pitched voices because they find them more attractive, subordinate, feminine, healthier and younger-sounding. In the new study, detailed in a recent issue of the journal Biology Letters, Feinberg set out to see how that attraction to deeper-voiced men affected reproduction and the survival of offspring. "While we find in this new study that voice pitch is not related to offspring mortality rates," Feinberg said, "we find that men with low voice pitch have higher reproductive success and more children born to them." To look for any relationship between voice pitch and birth rates, the researchers studied the Hadza tribe of Tanzania, one of the last true hunter-gatherer cultures. Because the Hadza have no modern birth control, the researchers were able to compare birth rates without any outside influencing factors. © 2007 MSNBC.com © 2007 Microsoft

Keyword: Sexual Behavior; Evolution
Link ID: 10774 - Posted: 06.24.2010

Researchers at the University of Warwick's Warwick Medical School studied 10,308 British civil servants in two different time periods: between 1985 and 1988, and between 1992 and 1993. Study participants who slept longer than eight hours were more than twice as likely to die as those who kept sleeping for seven. Researchers believe depression, low socioeconomic status and cancer-related fatigue could play a part. (CBC) With seven hours seen as the optimal amount of sleep for the average adult, the study subjects who cut the duration of their sleep from seven hours to five hours a night had a 1.7-fold increased risk of death from all causes, according to the research, presented Monday to the British Sleep Society. They also had twice the increased risk of death from a cardiovascular problem. More surprisingly, scientists found those individuals who increased the number of hours they slept per night from seven to eight hours or more were more than twice as likely to die as those who kept sleeping for seven. They were also more likely to die from non-cardiovascular diseases. "Short sleep has been shown to be a risk factor for weight gain, hypertension and Type 2 diabetes sometimes leading to mortality,' said Francesco Cappuccio, an author of the study. © CBC 2007

Keyword: Sleep; Neuroimmunology
Link ID: 10773 - Posted: 06.24.2010

LONDON - People who do not get enough sleep are more than twice as likely to die of heart disease, according to a large British study released on Monday. Although the reasons are unclear, researchers said lack of sleep appeared to be linked to increased blood pressure, which is known to raise the risk of heart attacks and stroke. A 17-year analysis of 10,000 government workers showed those who cut their sleeping from seven hours a night to five or less faced a 1.7-fold increased risk in mortality from all causes and more than double the risk of cardiovascular death. The findings highlight a danger in busy modern lifestyles, Francesco Cappuccio, professor of cardiovascular medicine at the University of Warwick's medical school, told the annual conference of the British Sleep Society in Cambridge. "A third of the population of the U.K. and over 40 percent in the U.S. regularly sleep less than five hours a night, so it is not a trivial problem," he said in a telephone interview. "The current pressures in society to cut out sleep, in order to squeeze in more, may not be a good idea — particularly if you go below five hours." © 2007 MSNBC.com © 2007 Microsoft

Keyword: Sleep; Neuroimmunology
Link ID: 10772 - Posted: 06.24.2010

Jennifer Viegas, Discovery News — Big-headed people could be brainier too, according to a new analysis of a 1939 study comparing head size and intelligence in a group of male prisoners. Although the effect of head size on IQ is minimal, it does exist, says Jeremy Genovese, who conducted the new research and is an associate professor of human development and educational psychology at Cleveland State University. "The correlations between head size and IQ are quite modest, and you cannot determine someone's intelligence with a tape measure," he told Discovery News. "However, the correlation is real and might have some clinical significance, such as predicting susceptibility to dementia." Genovese explained that "larger bodies do require larger brains to support larger nervous systems," but he added that the notable difference in body size between men and women appears to have "no relationship to intelligence." For the study, which has been accepted for publication in the journal Personality and Individual Differences, Genovese obtained copies of the 1939 inmate data, which was collected by Harvard anthropologist Earnest Albert Hooten. Hooten gathered anthropological and sociological records on roughly 12 percent of American prison inmates. © 2007 Discovery Communications

Keyword: Intelligence
Link ID: 10771 - Posted: 06.24.2010

Roxanne Khamsi Hormone replacement therapy massively boosts sexual interest in post-menopausal women, suggests a new study. Women taking HRT therapy, typically used to treat symptoms of menopause such as "hot flashes", reported a 44% increase in sexual interest in the recent trial. Researchers say this finding supports the idea that the hormone treatment, which consists of oestrogen and progesterone, can help women frustrated by a decline in libido following menopause. Experts say, however, that patients must carefully weigh the benefits of such treatment against the possible negative side effects, which include an increased risk of cancer. Menopause has a huge impact on women, leading sometimes to bone loss known as osteoporosis and facial hair growth. The hormonal changes of menopause can also lead to clitoral atrophy and vaginal dryness, which can make sex less pleasurable. Previous studies have estimated that anywhere from 30% to 70% of women report a decline in libido following menopause for various reasons, according to Jim Pfaus at Concordia University in Montreal, Quebec in Canada. Pfaus adds that sex therapy cannot necessarily boost libido in women who have passed menopause since their loss of interest in sex often has a biological cause. “You can't cognitively treat your hormone levels,” he says. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 10770 - Posted: 06.24.2010

By Deborah Mitchell CHICAGO (Reuters Health) - Physicians, nurses and other health care providers should be aware that patients receiving intravenous treatment with the antifungal drug voriconazole may develop a range of neurological side effects, including auditory and visual hallucinations, according to a report presented at the 47th annual Interscience Conference on Antimicrobial Agents and Chemotherapy. Voriconazole, sold under the trade name Vfend, is a relatively new drug used to treat serious fungus infections, such as invasive mold infections and invasive candidiasis. Many of these patients are extremely ill and are receiving several different drugs, which makes it difficult to distinguish the side effects of specific drugs from the symptoms of the underlying illness. To estimate the frequency and seriousness of voriconazole side effects, Dr. Dimitrios Zonios and colleagues at the National Institutes of Health in Bethesda, Maryland, evaluated patients in an ongoing prospective study that was assessing voriconazole toxicity. The researchers focused on side effects of the central nervous system, which are not well characterized for the drug. Between March 2006 and June 2007, the researchers evaluated 66 cancer patients who were being treated with intravenous voriconazole at their institution. Careful interviews and toxicity evaluations were conducted for each patient. © 1996-2007 Scientific American, Inc

Keyword: Neurotoxins
Link ID: 10769 - Posted: 06.24.2010

Brian Vastag Zakir Ramazanov first encountered Rhodiola rosea in 1979 as a Soviet soldier in Afghanistan. A comrade often received boxes full of the yellow-flowered mountain herb from his home in Siberia and would prepare and share a sweet-smelling tea from the root. Ramazanov found that the drink seemed to quicken his hiking and speed his recovery after a taxing mission. After Ramazanov left the army, he forgot about the Siberian herb. Despite having a good job, he felt depressed, and flashbacks from the war interfered with his daily tasks. After trying various drugs and natural remedies to ease his symptoms, he happened upon a lecture about rhodiola. He learned that the Soviets had been studying the herb since the 1940s, feeding it to Olympic athletes and cosmonauts. Government scientists had noted that rhodiola boosted the body's response to stress. If it was good enough for weight lifters and space travelers, it was good enough for him, Ramazanov thought. He began taking rhodiola extracts, and after a month his symptoms lifted. He had more energy during the day and could finally sleep at night. The horrific war images faded and his concentration improved. After the Soviet Union collapsed, Ramazanov moved to New York State, began translating Russian rhodiola research, and started a small business to import the herb. A few years later, Richard Brown, a psychiatrist at Columbia University College of Physicians and Surgeons, heard about rhodiola from two of his patients. They independently mentioned that the herb, sold as a dietary supplement in the United States by a company affiliated with Ramazanov, had eased their depression. ©2007 Science Service

Keyword: Depression
Link ID: 10768 - Posted: 06.24.2010

Bruce Bower The earliest known human ancestors that trekked from Africa into Asia possessed legs, feet, and spines much like ours, even as they sported relatively apelike arms and small brains, according to an analysis of 1.77-million-year-old fossils unearthed in the central Asian nation of Georgia. A team led by David Lordkipanidze of the Georgian National Museum in Tbilisi recovered 33 lower-body bones from at least three adults and one teenager at a site called Dmanisi. The researchers had previously found four skulls and four lower jaws, as well as simple stone tools, in the same sediment (SN: 5/13/00, p. 308). In several cases, skull and lower-body remains come from the same individual. The researchers classify these ancient finds as early Homo. The fossils might be from an early form of Homo erectus that left eastern Africa for the Asian hinterlands, but a definitive species identity remains unclear, Lordkipanidze cautions. A description of the new finds appears in the Sept. 20 Nature. "The Dmanisi individuals weren't the first hominids [fossil ancestors of humans] to leave Africa," Lordkipanidze says. "They must have had more-primitive ancestors that passed through the Near East before reaching Georgia." ©2007 Science Service.

Keyword: Evolution
Link ID: 10767 - Posted: 06.24.2010

By Nikhil Swaminathan The phrase "Mozart Effect" conjures an image of a pregnant woman who, sporting headphones over her belly, is convinced that playing classical music to her unborn child will improve the tyke's intelligence. But is there science to back up this idea, which has spawned a cottage industry of books, CDs and videos? A short paper published in Nature in 1993 unwittingly introduced the supposed Mozart effect to the masses. Psychologist Frances Rauscher's study involved 36 college kids who listened to either 10 minutes of a Mozart sonata in D-major, a relaxation track or silence before performing several spatial reasoning tasks. In one test—determining what a paper folded several times over and then cut might look like when unfolded—students who had listened to Mozart seemed to show significant improvement in their performance (by about eight to nine spatial IQ points). Rauscher—whose work, unlike most scientists, is sometimes cited on the liner notes of CDs—remains puzzled as to how this narrow effect of classical music extended from a paper-folding task to general intelligence and from college students to children (and fetuses). "I think parents are very desperate to give their own children every single enhancement that they can," she surmises. In addition to a flood of commercial products in the wake of the finding, in 1998 then-Georgia governor Zell Miller mandated that mothers of newborns in the state be given classical music CDs. And in Florida, day care centers were required to pipe symphonies through their sound systems. © 1996-2007 Scientific American, Inc

Keyword: Development of the Brain; Hearing
Link ID: 10766 - Posted: 06.24.2010

FORT CAMPBELL, Ky. - Before they leave for Iraq, thousands of troops with the 101st Airborne Division line up at laptop computers to take a test: basic math, matching numbers and symbols, and identifying patterns. They press a button quickly to measure response time. It’s all part of a fledgling Army program that records how soldiers’ brains work when healthy, giving doctors baseline data to help diagnose and treat the soldiers if they suffer a traumatic brain injury — the signature injury of the Iraq war. “This allows the Army to be much more proactive,” said Lt. Col. Mark McGrail, division surgeon for the 101st. “We don’t want to wait until the soldier is getting out of the Army to say, ’But I’ve had these symptoms.”’ The mandatory brain-function tests are starting with the 101st at Fort Campbell and are expected to spread to other military bases in the next couple of months. Commanders at each base will decide whether to adopt the program. The tests provide a standard, objective measurement for each soldier’s reaction time, their short-term memory and other cognitive skills. That data would be used when the soldiers come home to identify mild brain trauma that can often go unnoticed and untreated. © 2007 The Associated Press.

Keyword: Stress; Learning & Memory
Link ID: 10765 - Posted: 06.24.2010

By Christie Nicholson About three years ago Eva Salem got into some trouble with a crocodile. It snapped her hand in its jaws. In a panic, she managed to knock out the crocodile and free herself. Then, she woke up. "I imagine that's what it's like when you're on heroin. That's what my dreams were like—vivid, crazy and active," she says. Salem, a new mother, had been breast-feeding her daughter for five months before the croc-attack dream, living on four hours of sleep a night. If she did sleep a full night, her dreams boomeranged, becoming so vivid that she felt like she wasn't sleeping at all. Dreams are amazingly persistent. Miss a few from lack of sleep and the brain keeps score, forcing payback soon after eyelids close. "Nature's soft nurse," as Shakespeare called sleep, isn't so soft after all. "When someone is sleep deprived we see greater sleep intensity, meaning greater brain activity during sleep; dreaming is definitely increased and likely more vivid," says neurologist Mark Mahowald of the University of Minnesota and director of the Minnesota Regional Sleep Disorders Center in Minneapolis. The phenomenon is called REM rebound. REM refers to "rapid eye movement," the darting of the eyes under closed lids. In this state we dream the most and our brain activity eerily resembles that of waking life. Yet, at the same time, our muscles go slack and we lie paralyzed—a toe might wiggle, but essentially we can't move, as if our brain is protecting our bodies from acting out the stories we dream. © 1996-2007 Scientific American, Inc

Keyword: Sleep
Link ID: 10764 - Posted: 06.24.2010

By Robin Hilmantel, USA TODAY Whenever Leslie Lipton was handed a menu, she'd freeze. She suddenly would feel that all eyes were upon her, noticing and judging her eating habits. This was something she couldn't quite swallow when she was a teenager. "I'd sit there, and I'd wait, and I'd see what everyone else was ordering before I ordered," says Lipton, now 21 and a student at Barnard College in New York City. Lunch in the high school cafeteria felt like a competition. "Everyone would be looking at everyone else's tray to see what everyone else was eating," says Lipton. "If you eat less, at least the comparisons are good." Lipton says this reluctance to eat in public was the prologue to her anorexia, the starvation eating disorder from which she has since recovered. But, she says, many girls across the country avoid food in public even if they eat normally at home. This self-conscious group is convinced that without the classical symptoms of an eating disorder, such as extreme weight loss, there's no problem. But parents and friends are often left wondering at what point such behavior indicates that an eating disorder is brewing. Lipton, who now speaks to girls across the country about eating disorders and her recovery, says the phenomenon is "rampant." The author of Unwell: A Novel, which was published last year, Lipton blames society's emphasis on thinness. "People don't seem to look at girls as needing food," she says. Copyright 2007 USA TODAY,

Keyword: Anorexia & Bulimia
Link ID: 10763 - Posted: 09.21.2007

The developing nervous system is a seemingly chaotic and exceedingly complex jumble of cells with specialized missions, unique architectures, and stereotyped patterns of neuronal connections, or synapses. How neurons' dendrites and axons weave themselves into precise neural circuits during development remains a challenging question in neurobiology. What are the molecular tags on the surface of neurons that allow them to distinguish between each other? A single gene capable of producing more than 38,000 cell surface proteins is an essential tool in assuring the assembly of precise neural circuits in the fruit fly, Drosophila melanogaster. Now, two teams of researchers from the Howard Hughes Medical Institute (HHMI) have demonstrated how these closely related proteins establish the specificity that allows them to serve as identification tags for individual neurons. In work published in the September 21, 2007, issue of the journal Cell, research teams led by HHMI researchers S. Lawrence Zipursky of the University of California at Los Angeles (UCLA) and David Baker of the University of Washington worked together to describe how each of 18,048 different versions of the Dscam protein is able to recognize and bind only to an identical form of the protein. © 2007 Howard Hughes Medical Institute.

Keyword: Development of the Brain; Genes & Behavior
Link ID: 10762 - Posted: 06.24.2010