By Scicurious Stress is generally not a good thing. Most of us who live stressful lives (which, I suppose, would be all of us), are well aware of this. We try to reduce our stress, or even stress about how stressed we are. Traumatic stress increases the risk for all sorts of psychiatric disorders, including major depressive disorder, anxiety, and post traumatic stress disorder. But not all stresses are created equal, even the traumatic ones. And it turns out that it’s not the stress itself that is important…it’s whether or not you have any control over it. A stress that you can control is a very different one from a stress that you can’t. I usually think of a stress you cannot control as something like the illness of a family member, as compared to a stress you can control, say, the stress involved in training for and running a marathon (which is definitely a physical stressor). These are both stresses, but they aren’t alike. While the stress that you cannot control is often a very traumatic experience, and can predispose people to psychiatric disorders, a controllable stress is actually a good event. Not only does it blunt the impact of the stressor itself, it can be protective against the detriments of future uncontrolled stresses. Scientists call this “behavioral immunization” against future stress. Behavioral immunization involves the recruitment of very specific brain regions, especially the medial prefrontal cortex of the brain. After exposure to a controllable stress, there is increased activity in the medial prefrontal cortex, and it is thought that the increase in activity is important for the development of behavioral immunization. If you stop this increased activity from taking place during controllable stress, you can prevent behavioral immunization. © 2012 Scientific American

Keyword: Stress
Link ID: 17461 - Posted: 11.07.2012

Mo Costandi General anaesthetics induce a coma-like state within seconds, allowing patients to be operated on without feeling pain or discomfort. Yet very little is known about how these drugs work. Now research published today in the Proceedings of the National Academy of Sciences1 shows that they change the activity of specific regions of the brain and make it difficult for the different parts to talk to each other. Neuroscientist Laura Lewis of the Massachusetts Institute of Technology in Cambridge and her colleagues used microelectrodes to measure the activity of single cells and networks of neurons in the brains of three people who were about to undergo neurosurgery for epilepsy. Each patient was given a single dose of the general anaesthetic propofol, and their ability to respond to auditory stimuli was used to determine when they slipped into unconsciousness. The researchers found that loss of consciousness coincided with the rapid onset of brain waves known as slow oscillations. “We were surprised to find that slow oscillations began so abruptly,” says Lewis. “Their onset was sudden, and precisely timed to when patients lost consciousness.” The oscillations started at different times in different regions of the cerebral cortex, and individual neurons became markedly less active overall, with their activity spiking at the same time as the slow oscillations in that region. © 2012 Nature Publishing Group

Keyword: Sleep
Link ID: 17460 - Posted: 11.06.2012

by Virginia Morell Figaro may not be as talented an inventor as Leonardo da Vinci, but among Goffin's cockatoos, he's a prodigy. In their natural habitat—the forests of Indonesia these cockatoos have never been seen making or using tools. But researchers report today—that Figaro, a member of a captive colony of the birds in Austria, invents and uses stick tools of his own design. Although toolmaking and use is not uncommon in animals, this type of spontaneous innovation and individual creativity is "exceedingly rare" among nonhuman animals, the scientists note, and opens up many questions about the cognitive skills required. Understanding these processes, they say, may help unlock many of the questions about the evolution of intelligence. Many species of birds, such as woodpecker finches of the Galapagos Islands, ravens, crows, and herons, are natural toolmakers and users. New Caledonian crows are especially talented, shaping bits of wood and stiff palm leaves into spears and hooks to forage for grubs. One captive New Caledonian crow displayed an inventiveness similar to Figaro's by fashioning hooks (a shape she had not previously seen) out of wire. And captive Northern blue jays, which are not tool-users in the wild, have shredded newspaper to use as rakes for retrieving food pellets. Such talents haven't been seen before in cockatoos—and although tool use is seen in many species, innovative tool manufacture is rare. But even if Figaro is a standalone talent among his species, says Frans de Waal, a primatologist at Emory University in Atlanta, the discovery of such skills in even one individual shows that "general intelligence can lead to innovative behavior." Inventiveness is thus not tied to some type of mental specialization, such as being a natural tool-user, as has been argued previously, he explains. © 2010 American Association for the Advancement of Science.

Keyword: Intelligence; Evolution
Link ID: 17459 - Posted: 11.06.2012

by Virginia Morell Alex, an African grey parrot who died 5 years ago and was known for his ability to use English words, also understood a great deal about numbers. In a new study in this month's Cognition, scientists show that Alex correctly inferred the relationship between cardinal and ordinal numbers, an ability that has not previously been found in any species other than humans. After learning the cardinal numbers—or exact values—of one to six, Alex was taught the ordinal values (the position of a number in a list) of seven and eight—that is, he learned that six is less than seven, and seven is less than eight. He was never taught the cardinal values of seven and eight—but when tested on this, he passed with flying colors, apparently inferring, for instance, that the sound "seven" meant six plus one. In the video above of one of these experiments, comparative psychologist Irene Pepperberg of Harvard University asks Alex to pick out the set of colored blocks that equal the number seven. Play the video to hear his answer. © 2010 American Association for the Advancement of Science.

Keyword: Intelligence; Evolution
Link ID: 17458 - Posted: 11.06.2012

By James Gallagher Health and science reporter, BBC News Researchers have found some of the earliest signs of Alzheimer's disease, more than two decades before the first symptoms usually appear. Treating the disease early is thought to be vital to prevent damage to memory and thinking. A study, published in the Lancet Neurology, found differences in the brains of an extended Colombian family predisposed to develop an early form of Alzheimer's. Experts said the US study may give doctors more time to treat people. Alzheimer's disease starts long before anyone would notice; previous studies have shown an effect on the brain 10-15 years before symptoms. It is only after enough brain cells have died that the signs of dementia begin to appear - some regions of the brain will have lost up to 20% of their brain cells before the disease becomes noticeable. However, doctors fear so much of the brain will have degenerated by this time that it will be too late to treat patients. The failure of recent trials to prevent further cognitive decline in patients with mild to moderate Alzheimer's disease has been partly put down to timing. BBC © 2012

Keyword: Alzheimers
Link ID: 17457 - Posted: 11.06.2012

The brain holds in mind what has just been seen by synchronizing brain waves in a working memory circuit, an animal study supported by the National Institutes of Health suggests. The more in-sync such electrical signals of neurons were in two key hubs of the circuit, the more those cells held the short-term memory of a just-seen object. Charles Gray, Ph.D., of Montana State University, Bozeman, and colleagues, report their findings Nov. 1, 2012, online, in the journal Science Express. "This work demonstrates, for the first time, that there is information about short term memories reflected in in-sync brainwaves," explained Gray. "The Holy Grail of neuroscience has been to understand how and where information is encoded in the brain. This study provides more evidence that large scale electrical oscillations across distant brain regions may carry information for visual memories," said NIMH director Thomas R. Insel, M.D. Prior to the study, scientists had observed synchronous patterns of electrical activity between the two circuit hubs after a monkey saw an object, but weren’t sure if the signals actually represent such short-term visual memories in the brain. Rather, it was thought that such neural oscillations might play the role of a traffic cop, directing information along brain highways. To find out more, Gray, Rodrigo Salazar Ph.D., and Nick Dotson of Montana State and Steven Bressler, Ph.D., at Florida Atlantic University, Boca Raton, recorded electrical signals from groups of neurons in both hubs of two monkeys performing a visual working memory task. To earn a reward, the monkeys had to remember an object — or its location — that they saw momentarily on a computer screen and correctly match it. The researchers expected to see the telltale boost in synchrony during a delay period immediately after an object disappeared from the screen, when the monkey had to hold information briefly in mind.

Keyword: Learning & Memory
Link ID: 17456 - Posted: 11.06.2012

By Meghan Rosen Michael McAlpine’s shiny circuit doesn’t look like something you would stick in your mouth. It’s dashed with gold, has a coiled antenna and is glued to a stiff rectangle. But the antenna flexes, and the rectangle is actually silk, its stiffness melting away under water. And if you paste the device on your tooth, it could keep you healthy. The electronic gizmo is designed to detect dangerous bacteria and send out warning signals, alerting its bearer to microbes slipping past the lips. Recently, McAlpine, of Princeton University, and his colleagues spotted a single E. coli bacterium skittering across the surface of the gadget’s sensor. The sensor also picked out ulcer-causing H. pylori amid the molecular medley of human saliva, the team reported earlier this year in Nature Communications. At about the size of a standard postage stamp, the dental device is still too big to fit comfortably in a human mouth. “We had to use a cow tooth,” McAlpine says, describing test experiments. But his team plans to shrink the gadget so it can nestle against human enamel. McAlpine is convinced that one day, perhaps five to 10 years from now, everyone will wear some sort of electronic device. “It’s not just teeth,” he says. “People are going to be bionic.” McAlpine belongs to a growing pack of tech-savvy scientists figuring out how to merge the rigid, brittle materials of conventional electronics with the soft, curving surfaces of human tissues. Their goal: To create products that have the high performance of silicon wafers — the crystalline material used in computer chips — while still moving with the body. © Society for Science & the Public 2000 - 2012

Keyword: Robotics
Link ID: 17455 - Posted: 11.05.2012

By ANDREW SOLOMON Drew Petersen didn’t speak until he was 3½, but his mother, Sue, never believed he was slow. When he was 18 months old, in 1994, she was reading to him and skipped a word, whereupon Drew reached over and pointed to the missing word on the page. Drew didn’t produce much sound at that stage, but he already cared about it deeply. “Church bells would elicit a big response,” Sue told me. “Birdsong would stop him in his tracks.” Sue, who learned piano as a child, taught Drew the basics on an old upright, and he became fascinated by sheet music. “He needed to decode it,” Sue said. “So I had to recall what little I remembered, which was the treble clef.” As Drew told me, “It was like learning 13 letters of the alphabet and then trying to read books.” He figured out the bass clef on his own, and when he began formal lessons at 5, his teacher said he could skip the first six months’ worth of material. Within the year, Drew was performing Beethoven sonatas at the recital hall at Carnegie Hall. “I thought it was delightful,” Sue said, “but I also thought we shouldn’t take it too seriously. He was just a little boy.” On his way to kindergarten one day, Drew asked his mother, “Can I just stay home so I can learn something?” Sue was at a loss. “He was reading textbooks this big, and they’re in class holding up a blowup M,” she said. Drew, who is now 18, said: “At first, it felt lonely. Then you accept that, yes, you’re different from everyone else, but people will be your friends anyway.” Drew’s parents moved him to a private school. They bought him a new piano, because he announced at 7 that their upright lacked dynamic contrast. “It cost more money than we’d ever paid for anything except a down payment on a house,” Sue said. When Drew was 14, he discovered a home-school program created by Harvard; when I met him two years ago, he was 16, studying at the Manhattan School of Music and halfway to a Harvard bachelor’s degree. © 2012 The New York Times Company

Keyword: Development of the Brain; Intelligence
Link ID: 17454 - Posted: 11.05.2012

By Evan Charney and William English Dozens of studies in the past few years have linked single genes to whether a person is liberal or conservative, has a strong party affiliation or is likely to vote reguarly. The discipline of “genopolitics” has grabbed headlines as a result, but is the claim that a few genes influence political views and actions legitimate? We don't think so. The kinds of studies that have produced many of the findings we question involve searching for connections between behavior and gene variants that occur frequently in the population. Most of the 20,000 to 25,000 human genes come in hundreds or thousands of common variations, which often consist of slight differences in a gene's sequence of DNA code letters or in repeats of a particular segment. For the most part, scientists do not know what effect, if any, these common variants, known as polymorphisms, have on the functioning of the proteins they encode. Genes predict certain well-defined physiological diseases—such as hereditary breast cancer and the risk of developing Alzheimer's disease—but when it comes to complex human behaviors such as voting, the link is tenuous at best. One of the most prominent papers showing a link between a few polymorphisms and political behavior was published by James Fowler and Christopher Dawes in 2008 in the Journal of Politics. They concluded that people who possess certain variants of a gene called MAOA are more likely to vote than those who do not and that people with a particular variant of a gene known as 5-HTT who regularly attend religious services are also more likely to vote. We do not believe that these conclusions are right. © 2012 Scientific American

Keyword: Emotions; Genes & Behavior
Link ID: 17453 - Posted: 11.05.2012

By OLIVER SACKS HALLUCINATIONS are very startling and frightening: you suddenly see, or hear or smell something — something that is not there. Your immediate, bewildered feeling is, what is going on? Where is this coming from? The hallucination is convincingly real, produced by the same neural pathways as actual perception, and yet no one else seems to see it. And then you are forced to the conclusion that something — something unprecedented — is happening in your own brain or mind. Are you going insane, getting dementia, having a stroke? In other cultures, hallucinations have been regarded as gifts from the gods or the Muses, but in modern times they seem to carry an ominous significance in the public (and also the medical) mind, as portents of severe mental or neurological disorders. Having hallucinations is a fearful secret for many people — millions of people — never to be mentioned, hardly to be acknowledged to oneself, and yet far from uncommon. The vast majority are benign — and, indeed, in many circumstances, perfectly normal. Most of us have experienced them from time to time, during a fever or with the sensory monotony of a desert or empty road, or sometimes, seemingly, out of the blue. Many of us, as we lie in bed with closed eyes, awaiting sleep, have so-called hypnagogic hallucinations — geometric patterns, or faces, sometimes landscapes. Such patterns or scenes may be almost too faint to notice, or they may be very elaborate, brilliantly colored and rapidly changing — people used to compare them to slide shows. At the other end of sleep are hypnopompic hallucinations, seen with open eyes, upon first waking. These may be ordinary (an intensification of color perhaps, or someone calling your name) or terrifying (especially if combined with sleep paralysis) — a vast spider, a pterodactyl above the bed, poised to strike. © 2012 The New York Times Company

Keyword: Sleep; Schizophrenia
Link ID: 17452 - Posted: 11.05.2012

By Maureen McCarthy October 30th marked the five-year anniversary of the death of my friend Washoe. Washoe was a wonderful friend. She was confident and self-assured. She was a matriarch, a mother figure not only to her adopted son but to others as well. She was kind and caring, but she didn’t suffer fools. Washoe also happened to be known around the world as the first nonhuman to acquire aspects of a human language, American Sign Language. You see, my friend Washoe was a chimpanzee. Washoe was born somewhere in West Africa around September 1965. Much like the chimpanzees I study here in Uganda, Washoe’s mother cared for her during infancy, nursing her, carrying her, and sharing her sleeping nests with her. That changed when her mother was killed so baby Washoe could be taken from her forest home, then bought by the US Air Force for use in biomedical testing. Washoe was not used in this sort of testing, however. Instead, Drs. Allen and Beatrix Gardner of the University of Nevada chose her among the young chimpanzees at Holloman Aeromedical Laboratory to be cross-fostered. Cross-fostering occurs when a youngster of one species is reared by adults of a different species. In this case, humans raised Washoe exactly as if she were a deaf human child. She learned to brush her teeth, drink from cups, and dress herself, in the same way a human child learns these behaviors. She was also exposed to humans using sign language around her. In fact, humans used only American Sign Language (ASL) to communicate in Washoe’s presence, avoiding spoken English so as to replicate as accurately as possible the learning environment of a young human exposed to sign language. © 2012 Scientific American

Keyword: Language; Evolution
Link ID: 17451 - Posted: 11.05.2012

By James Gallagher Health and science reporter, BBC News A new drug is the "most effective" treatment for relapsing-remitting multiple sclerosis, say UK researchers. During MS the body's immune system turns on its own nerves causing debilitating muscle problems. Researchers at the University of Cambridge say a cancer drug, which wipes out and resets the immune system, has better results than other options. However, there is concern that a drugs company is about to increase the cost of the drug as a result. Around 100,000 people in the UK have multiple sclerosis. When the condition is diagnosed most will have a form of the disease know as relapsing-remitting MS, in which the symptoms can almost disappear for a time, before suddenly returning. Built from scratch The researchers tested a leukaemia drug, alemtuzumab, which had shown benefits for MS in small studies. In leukaemia, a blood cancer, it controls the excess production of white blood cells. In MS patients, the dose eliminates the immune cells entirely, forcing a new immune system to be built from scratch which should not attack the nerves. Two trials, published in the Lancet medical journal, compared the effectiveness of alemtuzumab with a first-choice drug, interferon beta-1a. BBC © 2012

Keyword: Multiple Sclerosis; Neuroimmunology
Link ID: 17450 - Posted: 11.03.2012

By DENISE GRADY Just when they might have thought they were in the clear, people recovering from meningitis in an outbreak caused by a contaminated steroid drug have been struck by a second illness. The new problem, called an epidural abscess, is an infection near the spine at the site where the drug — contaminated by a fungus — was injected to treat back or neck pain. The abscesses are a localized infection, different from meningitis, which affects the membranes covering the brain and spinal cord. But in some cases, an untreated abscess can cause meningitis. The abscesses have formed even while patients were taking powerful antifungal medicines, putting them back in the hospital for more treatment, often with surgery. The problem has just begun to emerge, so far mostly in Michigan, which has had more people sickened by the drug — 112 out of 404 nationwide — than any other state. “We’re hearing about it in Michigan and other locations as well,” said Dr. Tom M. Chiller, the deputy chief of the mycotic diseases branch of the Centers for Disease Control and Prevention. “We don’t have a good handle on how many people are coming back.” He added, “We are just learning about this and trying to assess how best to manage these patients. They’re very complicated.” In the last few days, about a third of the 53 patients treated for meningitis at St. Joseph Mercy Hospital in Ann Arbor, Mich., have returned with abscesses, said Dr. Lakshmi K. Halasyamani, the chief medical officer. © 2012 The New York Times Company

Keyword: Miscellaneous
Link ID: 17449 - Posted: 11.03.2012

By Hannah Krakauer, Last week, the Food and Drug Administration released incident reports describing several deaths that have occurred following the consumption of Monster Energy drinks. Much of the concern over energy-drink consumption centers on the high caffeine content of such beverages. How did these deaths come to light? Anais Fournier, 14, of Hagerstown, Md., died suddenly last December from a heart arrhythmia that led to cardiac arrest. She had apparently drunk two Monster Energy drinks over two days. In mid-October, Fournier’s mother, Wendy Crossland, filed a lawsuit against Monster Beverage, based in Corona, Calif., claiming that the company did not make clear the risks that come with drinking the beverage. As part of a Freedom of Information request by Crossland, the FDA released details of the other four cases, plus one nonfatal heart attack, all of which are alleged to be associated with drinking Monster Energy. The company maintains that its drinks are safe. How much caffeine is in energy drinks such as Monster Energy? Actually, not a huge amount. A 24-ounce can of Monster Energy contains 240 milligrams of caffeine. A typical eight-ounce cup of brewed coffee contains 90 to 200 milligrams of caffeine. © 1996-2012 The Washington Post

Keyword: Drug Abuse
Link ID: 17448 - Posted: 11.03.2012

Kerry Grens Fewer than five percent of patients prescribed narcotics to treat chronic pain become addicted to the drugs, according to a new analysis of past research. The finding suggests that concerns about the risk of becoming addicted to prescription painkillers might be "overblown," said addiction specialist Dr. Michael Fleming at Northwestern University's Feinberg School of Medicine. "If you're a person that doesn't have a history of addiction and doesn't have any major psychiatric problems, narcotics are relatively safe as long as your doctor doesn't give you too much and uses the right medication," Fleming, who was not involved in the new study, told Reuters Health. Some recent research has concluded the same thing, but another expert remained skeptical about the new report because many of the studies it included were not considered the best quality research, and they varied widely in their results. Advertise | AdChoices "I think the jury's still out" on how worrisome prescription opioid addiction is, said Joseph Boscarino of the Geisinger Clinic in Danville, Pennsylvania, who studies pain and addiction. Opioid painkillers, which include oxycodone, fentanyl and morphine, have only recently become available for patients with chronic pain, said Boscarino, who was not part of the new study. © 2012 NBCNews.com

Keyword: Drug Abuse; Pain & Touch
Link ID: 17447 - Posted: 11.03.2012

SAM KIM, Associated Press SEOUL, South Korea (AP) — An elephant in a South Korean zoo is using his trunk to pick up not only food, but also human vocabulary. An international team of scientists confirmed Friday what the Everland Zoo has been saying for years: Their 5.5-ton tusker Koshik has an unusual and possibly unprecedented talent. The 22-year-old Asian elephant can reproduce five Korean words by tucking his trunk inside his mouth to modulate sound, the scientists said in a joint paper published online in Current Biology. They said he may have started imitating human speech because he was lonely. Koshik can reproduce "annyeong" (hello), "anja" (sit down), "aniya" (no), "nuwo" (lie down) and "joa" (good), the paper says. One of the researchers said there is no conclusive evidence that Koshik understands the sounds he makes, although the elephant does respond to words like "anja." Everland Zoo officials in the city of Yongin said Koshik also can imitate "ajik" (not yet), but the researchers haven't confirmed the accomplishment. Koshik is particularly good with vowels, with a rate of similarity of 67 percent, the researchers said. For consonants he scores only 21 percent. Researchers said the clearest scientific evidence that Koshik is deliberately imitating human speech is that the sound frequency of his words matches that of his trainers. © 2012 Hearst Communications Inc.

Keyword: Language; Evolution
Link ID: 17446 - Posted: 11.03.2012

By MARGALIT FOX Arthur R. Jensen, an educational psychologist who ignited an international firestorm with a 1969 article suggesting that the gap in intelligence-test scores between black and white students might be rooted in genetic differences between the races, died on Oct. 22 at his home in Kelseyville, Calif. He was 89. His death was confirmed by the University of California, Berkeley, where he was an emeritus professor in the Graduate School of Education. Professor Jensen was deeply interested in differential psychology, a field whose central question — What makes people behave and think differently from one another? — strikes at the heart of the age-old nature-nurture debate. Because of his empirical work in the field on the quantification of general intelligence (a subject that had long invited a more diffuse, impressionistic approach), he was regarded by many colleagues as one of the most important psychologists of his day. But a wider public remembered him almost exclusively for his 1969 article “How Much Can We Boost I.Q. and Achievement?” Published in The Harvard Educational Review, a scholarly journal, the article quickly became — and remains even now — one of the most controversial in psychology. In the article, Professor Jensen posited two types of learning ability. Level I, associative ability, entailed the rote retention of facts. Level II, conceptual ability, involved abstract thinking and problem-solving. This type, he argued, was roughly equivalent to general intelligence, denoted in psychology by the letter “g.” © 2012 The New York Times Company

Keyword: Intelligence; Genes & Behavior
Link ID: 17445 - Posted: 11.03.2012

By DAN HURLEY IN the back room of a suburban storefront previously occupied by a yoga studio, Nick Vecchiarello, a 16-year-old from Glen Ridge, N.J., sits at a desk across from Kathryn Duch, a recent college graduate who wears a black shirt emblazoned with the words “Brain Trainer.” Spread out on the desk are a dozen playing cards showing symbols of varying colors, shapes and sizes. Nick stares down, searching for three cards whose symbols match. “Do you see it?” Ms. Duch asks encouragingly. “Oh, man,” mutters Nick, his eyes shifting among the cards, looking for patterns. Across the room, Nathan Veloric, 23, studies a list of numbers, looking for any two in a row that add up to nine. With tight-lipped determination, he scrawls a circle around one pair as his trainer holds a stopwatch to time him. Halfway through the 50 seconds allotted to complete the exercise, a ruckus comes from the center of the room. “Nathan’s here!” shouts Vanessa Maia, another trainer. Approaching him with a teasing grin, she claps her hands like an annoying little sister. “Distraction!” she shouts. “Distraction!” There is purpose behind the silliness. Ms. Maia is challenging the trainees to stay focused on their tasks in the face of whatever distractions may be out there, whether Twitter feeds, the latest Tumblr posting or old-fashioned classroom commotion. On this Wednesday evening at the Upper Montclair, N.J., outlet of LearningRx, a chain of 83 “brain training” franchises across the United States, the goal is to improve cognitive skills. LearningRx is one of a growing number of such commercial services — some online, others offered by psychologists. Unlike traditional tutoring services that seek to help students master a subject, brain training purports to enhance comprehension and the ability to analyze and mentally manipulate concepts, images, sounds and instructions. In a word, it seeks to make students smarter. © 2012 The New York Times Company

Keyword: Intelligence; Learning & Memory
Link ID: 17444 - Posted: 11.03.2012

By Gary Stix Nicotine enhances the ability to focus and remember. The alkaloid acts in a similar manner to the brain’s own signaling molecule, acetylcholine. It interacts with eponymous receptors on the surface of nerve cells to regulate signaling in the brain. The role of the nicotinic-acetylcholine receptors throughout the central nervous system is so wide-ranging that new discoveries about the molecule continue apace. A recent study published in Nature Neuroscience found that one type of nicotinic receptor acts as a key element in a cell that appears to perform a critical function in regulating memory. A team of researchers—led by one group from Uppsala University in Sweden and another from Rio Grande do Norte in Brazil—found that a type of nicotinic receptor on a cell called oriens lacunosum-moleculare (OLM-alpha 2) seems to be involved in turning on a critical circuit in the hippocampus, a brain structure involved with memory formation. “This cell has a significant influence on the incoming information to the hippocampus,” says Klas Kullander from Uppsala University. When this circuit is switched on, visual, auditory or other inputs to the hippocampus are targeted for additional processing of the incoming information, perhaps a means of flagging its importance so that it can be directed to the cerebral cortex for long-term storage of memory. The on-state of this circuit “prioritizes more intense local processing of the information,” Kullander says. “It lets the hippocampus dwell on the information longer.” © 2012 Scientific American

Keyword: Learning & Memory
Link ID: 17443 - Posted: 11.03.2012

By Laura Sanders Devoid of any external time cues, monkeys can still tell time. Animals learned to move their eyeballs once every second, a completely internal timing feat made possible by the rhythmic behavior of small groups of nerve cells, researchers propose online October 30 in PLOS Biology. Time is often measured with clues from the environment, says study coauthor Geoffrey Ghose of the University of Minnesota in Minneapolis. A quick glance at a clock indicates that your meeting will start soon, and a look outside at a low sun tells you that it’s time to leave work. But some time-telling abilities rely on purely internal processes — just a feeling that minutes, hours or days have ticked by, Ghose says. Ghose and Blaine Schneider, also of the University of Minnesota, studied this internal sensation of time by creating a situation in which two monkeys had to generate their own pattern without any outside help. The animals were trained to switch their gaze rhythmically between a red dot and a blue dot on a computer screen once every second, a job that looks like “they’re watching an extremely boring tennis match,” Ghose says. After a while, the monkeys got good, on average just tens of milliseconds off their tempo. Meanwhile, the researchers used electrodes to eavesdrop on the behavior of neurons in a part of the brain called the lateral intraparietal area. Earlier monkey studies found that neurons there build up activity with time, firing messages more and more frequently as the milliseconds tick by. © Society for Science & the Public 2000 - 2012

Keyword: Biological Rhythms; Hearing
Link ID: 17442 - Posted: 11.03.2012