Internal and Environmental Factors Trigger Unique Brain Activity in Teens

 

While the otherworldly behavior of teenagers is well documented, University of Pittsburgh researchers have taken a significant step toward finally unraveling the actual brain activity that can drive adolescents to engage in impulsive, self-indulgent, or self-destructive behavior. Published in the current edition of Behavioral Neuroscience, the Pitt study demonstrates that adolescent brains are more sensitive to internal and environmental factors than adult brains and suggests that the teenage tendency to experiment with drugs and develop psychological disorders could stem from this susceptibility.

Lead researcher Bita Moghaddam, a professor in the Department of Neuroscience in Pitt's School of Arts and Sciences, said that although the exact mechanics of the adolescent brain's reaction need further investigation, the current study is a starting point in mapping the neural path from stimuli to behavior in the adolescent brain. Pitt neuroscience doctoral student David Sturman was the Behavioral Neuroscience report's lead author, conducting the study with Moghaddam and Pitt research assistant Daniel Mandell. The project was supported by the National Institute of Mental Health.

"Adolescence is a period of volatility and vulnerability with tendencies toward interpersonal conflict, emotional reactivity, and risk behavior, but we know very little about the brain mechanisms that promote this state," Moghaddam said. "We want to know how the adolescent brain interacts with the environment at the brain-cell level, when the neural signals are firing. Once we identify how certain factors trigger teenage behavior, we might better understand-and possibly address-the origin of the risk taking and psychological disorders such as depression and schizophrenia that occur during this period."

The researchers trained adolescent and adult rats to respond to a visual light cue by rewarding them with sugar pellets. Previous research has shown that adolescent rats and mice exhibit behavioral differences from adults similar to those of adolescent humans, including greater impulsiveness, impatience, and vulnerability to psychological problems, the authors wrote. The rats were placed in front of three holes with the light behind the middle hole. If a rat poked its nose into the center hole when the light was activated, it received a pellet; if it explored the right or left hole, it got nothing. The researchers found that the adolescents responded to the light cue at least as readily as adult rats, suggesting a similar or slightly better capacity for learning.

After six days, the rats no longer received a reward for choosing the center hole. They were divided into four test groups, each with an equal number of adults and adolescents: rats that were given 20 percent less food between sessions and received the light cue; rats that received the light cue but could eat as much as they liked between sessions; a group that received less food and no light cue; and a group that could eat between sessions but was not shown the light cue during the experiments.

Moghaddam and her team found that adolescents tended to return to the center hole far more often than the adults although they received no reward and continued going to the hole long after the adult rats stopped altogether. Such doggedness was even more prominent in adolescents who received the light cue and had a restricted diet before the experiment. This group nosed the center hole 30 times, twice as often as adults under the same circumstances and as adolescents with less food and no light cue. Adolescents that received the cue and had free access to food made for the center hole only a third as often.

Thus, rats experiencing internal and external stimuli-hunger and the light cue-compulsively sought the earlier reward long after the other rats realized it no longer existed. These results suggest that human teenagers can similarly behave irrationally and compulsively when faced with certain feelings and settings, Moghaddam said. "A scenario could range from the relatively mundane, such as hungry teenagers being more likely than adults to buy fast food immediately after seeing an advertisement, to despair and relationship problems eliciting thoughts of suicide," she said.

For the project's next phase, the Pitt group will repeat the experiments while monitoring activity in the emotion and cognition centers of the adolescent and adult rats' brains, Moghaddam said. This information will help Moghaddam and her colleagues grasp how brain cells encode the behavioral signals sent in response to stimuli.

Midday Nap Markedly Boosts the Brain's Learning Capacity

 

If you see a student dozing in the library or a co-worker catching 40 winks in her cubicle, don't roll your eyes. New research from the University of California, Berkeley, shows that an hour's nap can dramatically boost and restore your brain power. Indeed, the findings suggest that a biphasic sleep schedule not only refreshes the mind, but can make you smarter.

 

Conversely, the more hours we spend awake, the more sluggish our minds become, according to the findings. The results support previous data from the same research team that pulling an all-nighter -- a common practice at college during midterms and finals -- decreases the ability to cram in new facts by nearly 40 percent, due to a shutdown of brain regions during sleep deprivation.

"Sleep not only rights the wrong of prolonged wakefulness but, at a neurocognitive level, it moves you beyond where you were before you took a nap," said Matthew Walker, an assistant professor of psychology at UC Berkeley and the lead investigator of these studies.

In the recent UC Berkeley sleep study, 39 healthy young adults were divided into two groups -- nap and no-nap. At noon, all the participants were subjected to a rigorous learning task intended to tax the hippocampus, a region of the brain that helps store fact-based memories. Both groups performed at comparable levels.

At 2 p.m., the nap group took a 90-minute siesta while the no-nap group stayed awake. Later that day, at 6 p.m., participants performed a new round of learning exercises. Those who remained awake throughout the day became worse at learning. In contrast, those who napped did markedly better and actually improved in their capacity to learn.

These findings reinforce the researchers' hypothesis that sleep is needed to clear the brain's short-term memory storage and make room for new information, said Walker, who presented his preliminary findings on Feb. 21, at the annual meeting of the American Association of the Advancement of Science (AAAS) in San Diego, Calif.

Since 2007, Walker and other sleep researchers have established that fact-based memories are temporarily stored in the hippocampus before being sent to the brain's prefrontal cortex, which may have more storage space.

"It's as though the e-mail inbox in your hippocampus is full and, until you sleep and clear out those fact e-mails, you're not going to receive any more mail. It's just going to bounce until you sleep and move it into another folder," Walker said.

In the latest study, Walker and his team have broken new ground in discovering that this memory- refreshing process occurs when nappers are engaged in a specific stage of sleep. Electroencephalogram tests, which measure electrical activity in the brain, indicated that this refreshing of memory capacity is related to Stage 2 non-REM sleep, which takes place between deep sleep (non-REM) and the dream state known as Rapid Eye Movement (REM). Previously, the purpose of this stage was unclear, but the new results offer evidence as to why humans spend at least half their sleeping hours in Stage 2, non-REM, Walker said.

"I can't imagine Mother Nature would have us spend 50 percent of the night going from one sleep stage to another for no reason," Walker said. "Sleep is sophisticated. It acts locally to give us what we need."

Walker and his team will go on to investigate whether the reduction of sleep experienced by people as they get older is related to the documented decrease in our ability to learn as we age. Finding that link may be helpful in understanding such neurodegenerative conditions as Alzheimer's disease, Walker said.

In addition to Walker, co-investigators of these new findings are UC Berkeley post-doctoral fellow Bryce A. Mander and psychology undergraduate Sangeetha Santhanam.

 

Youngest Extra-Solar Planet Discovered Around Solar-Type Star

 

Astronomers have discovered the youngest extra-solar planet around a solar-type star, named BD+20 1790b.

 

The giant planet, six-times the mass of Jupiter, is only 35 million years old. It orbits a young active central star at a distance closer than Mercury orbits the Sun. Young stars are usually excluded from planet searches because they have intense magnetic fields that generate a range of phenomena known collectively as stellar activity, including flares and spots. This activity can mimic the presence of a companion and so can make extremely difficult to disentangle the signals of planets and activity.

University of Hertfordshire astronomers, Dr Maria Cruz Gálvez-Ortiz and Dr John Barnes, are part of the international collaboration that made the discovery.

Dr Maria Cruz Gálvez-Ortiz, describing how the planet was discovered, said: "The planet was detected by searching for very small variations in the velocity of the host star, caused by the gravitational tug of the planet as it orbits -- the so-called 'Doppler wobble technique.' Overcoming the interference caused by the activity was a major challenge for the team, but with enough data from an array of large telescopes the planet's signature was revealed."

There is currently a severe lack of knowledge about early stages of planet evolution. Most planet-search surveys tend to target much older stars, with ages in excess of a billion years. Only one young planet, with an age of 100 million years, was previously known. However, at only 35 million years, BD+20 1790b is approximately three times younger. The detection of young planets will allow the testing of formation scenarios and to investigate the early stages of planetary evolution.

BD+20 1790b was discovered using observations made at different telescopes, including the Observatorio de Calar Alto (Almería, Spain) and the Observatorio del Roque de los Muchachos (La Palma, Spain) over the last five years. The discovery team is an international collaboration including: M.M. Hernán Obispo, E. De Castro and M. Cornide (Universidad Complutense de Madrid, Spain), M.C. Gálvez-Ortiz and J.R. Barnes, (University of Hertfordshire, U.K.), G. Anglada-Escudé (Carnegie Institution of Washington, USA) and S.R. Kane (NASA Exoplanet Institute, Caltech, USA).

The discovery has just been published in the journal Astronomy & Astrophysics.

 

Walking Linked to Eased Osteoarthritis, Study Suggests

 

 "Progressive walking" combined with glucosamine sulphate supplementation has been shown to improve the symptoms of osteoarthritis. Researchers writing in BioMed Central's open-access journal Arthritis Research and Therapy found that patients who walked at least two bouts of 1500 steps each on three days of the week reported significantly less arthritis pain, and significantly improved physical function.

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Dr Kristiann Heesch worked with a team of researchers from The University of Queensland, Australia, to carry out the trial in 36 osteoarthritis patients (aged 42-73 years). All patients received the dietary supplement for six weeks, after which they continued to take the supplement during a 12-week progressive walking program. The program, called Stepping Out, includes a walking guide; a pedometer; weekly log sheets and a weekly planner, all intended to help patients adopt the exercise regime.

Seventeen patients were randomly assigned to walk five days per week, while the remaining 19 were instructed to walk three days a week.

The team found that both groups achieved significant improvement in their symptoms, however being encouraged to walk five days a week was notmore effective than being encouraged to walk three days. "These findings are not surprising given that the three-day and five-day walking groups did not differ significantly in the mean number of days actually walked per week, the mean number of daily steps walked, nor their weekly minutes of physical activity," Dr Heesch said. "They provide preliminary evidence that osteoarthritis sufferers can benefit from a combination of glucosamine sulphate and walking 3000 steps per day for exercise, in bouts of at least 1500 steps each, on at least three days per week."

This amount of walking is less than current physical activity recommendations for the general population, but follows the recommendations for people with arthritis.

Drama or Reality TV: Do Medical Shows Depict Proper First Aid for Seizures?

http://www.sciencedaily.com/releases/2010/02/100214220102.htm

 

Watching TV medical shows might not be the best way to learn what to do when someone has a seizure. Researchers screened the most popular medical dramas and found that doctors and nurses on the shows responded inappropriately to seizures almost half the time, according to a study that will be presented at the American Academy of Neurology's 62nd Annual Meeting in Toronto April 10 to April 17, 2010.

 

"Television dramas are a potentially powerful method of educating the public about first aid and seizures," said study author Andrew Moeller, with Dalhousie University, Halifax, in Nova Scotia, Canada. "Our results, showing that television shows inaccurately showed seizure management half the time, are a call to action. People with epilepsy should lobby the television industry to adhere to guidelines for first aid management of seizures." Moeller worked alongside R. Mark Sadler, MD, also with Dalhousie University for the research.

For the study, researchers screened all episodes of the highest-rated US medical dramas: "Grey's Anatomy," "House, M.D.," and "Private Practice" and the last five seasons of "ER" for seizures. In the 327 episodes, 59 seizures occurred. Fifty-one seizures took place in a hospital. Nearly all first aid was performed by "nurses" or "doctors."

Guidelines on seizure management were used to determine whether the seizure was handled properly.

The study found that inappropriate practices, including holding the person down, trying to stop involuntary movements or putting something in the person's mouth, occurred in 25 cases, nearly 46 percent of the time. First aid management was shown appropriately in 17 seizures, or about 29 percent of the time. Appropriateness of first aid could not be determined in 15 incidents of seizures, or 25 percent.

Long-Distance Migration Shapes Butterfly Wings

A University of Georgia study has found that monarch butterflies that migrate long distances have evolved significantly larger and more elongated wings than their stationary cousins, differences that are consistent with traits known to enhance flight ability in other migratory species.

As part of a National Science Foundation and UGA-funded study, researchers in the Warnell School of Forestry and Natural Resources and the Odum School of Ecology examined the size and shape of monarchs from migratory and non-migratory populations using sophisticated computer imaging that was able to measure precise details about the insects' wings. Warnell doctoral candidate Andy Davis and Odum Associate Professor Sonia Altizer compared migratory monarchs from the eastern and western U.S. to those in Hawaii, Costa Rica, South Florida and Puerto Rico that do not migrate. They also measured the wings of lab-grown monarchs to rule out environmental causes of differences in size and shape, and to demonstrate a genetic basis for variation in wing traits among individual monarchs. Altizer and Davis' findings were recently published in the online edition of the scientific journal Evolution.

The findings in monarchs were consistent with previous studies comparing migratory and non-migratory bird species, which indicate that the best shape for long-distance flight involves long wings with a narrow tip to help reduce drag. In addition to their findings on wing size and shape, the team also found that monarchs from the two migratory populations in the U.S. differed in body size, suggesting that each population could have adapted to the demands of migration in subtly different ways. Larger bodies might help eastern monarchs, with their much longer migration, carry fat deposits to fuel the long journey and five-month overwintering period in Mexico.

Monarchs in eastern North America, famous for migrating the longest distances of any insect species in the world, face a number of threats, to the point that monarch migration is considered to be an "endangered phenomenon." Davis has published previous research indicating that female monarch butterflies are on a 30-year decline in the eastern U.S., a troubling pattern that paints a dire picture for population recruitment. Furthermore, monarchs from this population are prone to periodic population crashes from storms at the Mexican overwintering site. Although monarchs worldwide are not threatened, Altizer said, those with the larger wingspan are. "Our study shows that we would lose an evolutionarily unique population if the migration of eastern monarchs were to unravel," she said.

How The Moon Produces Its Own Water

The Moon is a big sponge that absorbs electrically charged particles given out by the Sun. These particles interact with the oxygen present in some dust grains on the lunar surface, producing water. This discovery, made by the ESA-ISRO instrument SARA onboard the Indian Chandrayaan-1 lunar orbiter, confirms how water is likely being created on the lunar surface.

It also gives scientists an ingenious new way to take images of the Moon and any other airless body in the Solar System.

The lunar surface is a loose collection of irregular dust grains, known as regolith. Incoming particles should be trapped in the spaces between the grains and absorbed. When this happens to protons they are expected to interact with the oxygen in the lunar regolith to produce hydroxyl and water. The signature for these molecules was recently found and reported by Chandrayaan-1’s Moon Mineralogy Mapper (M3) instrument team.

The SARA results confirm that solar hydrogen nuclei are indeed being absorbed by the lunar regolith but also highlight a mystery: not every proton is absorbed. One out of every five rebounds into space. In the process, the proton joins with an electron to become an atom of hydrogen. “We didn’t expect to see this at all,” says Stas Barabash, Swedish Institute of Space Physics, who is the European Principal Investigator for the Sub-keV Atom Reflecting Analyzer (SARA) instrument, which made the discovery.

Although Barabash and his colleagues do not know what is causing the reflections, the discovery paves the way for a new type of image to be made. The hydrogen shoots off with speeds of around 200 km/s and escapes without being deflected by the Moon’s weak gravity. Hydrogen is also electrically neutral, and is not diverted by the magnetic fields in space. So the atoms fly in straight lines, just like photons of light. In principle, each atom can be traced back to its origin and an image of the surface can be made. The areas that emit most hydrogen will show up the brightest.

Whilst the Moon does not generate a global magnetic field, some lunar rocks are magnetised. Barabash and his team are currently making images, to look for such ‘magnetic anomalies’ in lunar rocks. These generate magnetic bubbles that deflect incoming protons away into surrounding regions making magnetic rocks appear dark in a hydrogen image.

The incoming protons are part of the solar wind, a constant stream of particles given off by the Sun. They collide with every celestial object in the Solar System but are usually stopped by the body’s atmosphere. On bodies without such a natural shield, for example asteroids or the planet Mercury, the solar wind reaches the ground. The SARA team expects that these objects too will reflect many of the incoming protons back into space as hydrogen atoms.

This knowledge provides timely advice for the scientists and engineers who are readying ESA’s BepiColombo mission to Mercury. The spacecraft will be carrying two similar instruments to SARA and may find that the inner-most planet is reflecting more hydrogen than the Moon because the solar wind is more concentrated closer to the Sun.

SARA was one of three instruments that ESA contributed to Chandrayaan-1, the lunar orbiter that finished its mission in August 2009. The instrument was built jointly by scientific groups from Sweden, India, Japan, and Switzerland: Swedish Institute of Space Physics, Kiruna, Sweden; Vikram Sarabhai Space Centre, Trivandrum, India; University of Bern, Switzerland; and Institute of Space and Astronautical Science, Sagamihara, Japan. The instrument is led by Principal Investigators Stanislav Barabash, IRF, Sweden, and Anil Bhardwaj, VSSC, India.

Moms Influence How Children Develop Advanced Cognitive Functions

Executive functioning is a set of advanced cognitive functions -- such as the ability to control impulses, remember things, and show mental flexibility -- that help us plan and monitor what we do to reach goals. Although executive functioning develops speedily between ages 1 and 6, children vary widely in their skills in this area. Now a new longitudinal study tells us that moms play a role in how their children develop these abilities.

The study was conducted at the University of Montreal and the University of Minnesota. It appears in the January/February 2010 issue of the journal Child Development.

The researchers looked at 80 pairs of middle-income Canadian moms and their year-old babies. It turns out that the ways moms act when they're playing and solving puzzles with their babies can explain some of the differences in children's development of executive functioning.

Children of moms who answered their children's requests for help quickly and accurately; talked about their children's preferences, thoughts, and memories during play; and encouraged successful strategies to help solve difficult problems performed better at a year and a half and 2 years on tasks that call for executive skills than children of moms who didn't use these techniques in interacting with their youngsters.

"The study sheds light on the role parents play in helping children develop skills that are important for later school success and social competence," according to Annie Bernier, professor of psychology at the University of Montreal and the study's lead author.

Excessive Internet Use Is Linked to Depression

People who spend a lot of time browsing the Internet are more likely to show depressive symptoms, according to the first large-scale study of its kind in the West by University of Leeds psychologists.

Researchers found striking evidence that some users have developed a compulsive internet habit, whereby they replace real-life social interaction with online chat rooms and social networking sites. The results suggest that this type of addictive surfing can have a serious impact on mental health.

Lead author Dr Catriona Morrison, from the University of Leeds, said: "The internet now plays a huge part in modern life, but its benefits are accompanied by a darker side.

"While many of us use the internet to pay bills, shop and send emails, there is a small subset of the population who find it hard to control how much time they spend online, to the point where it interferes with their daily activities."

These 'internet addicts' spent proportionately more time browsing sexually gratifying websites, online gaming sites and online communities. They also had a higher incidence of moderate to severe depression than non-addicted users.

"Our research indicates that excessive internet use is associated with depression, but what we don't know is which comes first -- are depressed people drawn to the internet or does the internet cause depression?

"What is clear, is that for a small subset of people, excessive use of the internet could be a warning signal for depressive tendencies."

Incidents such as the spate of suicides among teenagers in the Welsh town of Bridgend in 2008 led many to question the extent to which social networking sites can contribute to depressive thoughts in vulnerable teenagers. In the Leeds study, young people were more likely to be internet addicted than middle-aged users, with the average age of the addicted group standing at 21 years.

"This study reinforces the public speculation that over-engaging in websites that serve to replace normal social function might be linked to psychological disorders like depression and addiction," added Dr Morrison. "We now need to consider the wider societal implications of this relationship and establish clearly the effects of excessive internet use on mental health."

This was the first large-scale study of Western young people to consider the relationship between internet addiction and depression. The internet use and depression levels of 1,319 people aged 16-51 were evaluated for the study, and of these, 1.2% were classed as being internet addicted. While small, this is larger than the incidence of gambling in the UK, which stands at 0.6%. The research will be published in the journal Psychopathology on 10th February.

Prayer Increases Forgiveness, Study Shows

We have all been guilty of a transgression at one time or another. That's because we're not perfect. We all commit hurtful acts, violate trust, and hope for forgiveness.

That's simply a fact, and here's another one: Nine out of 10 Americans say that they pray -- at least on occasion. Florida State University psychologist Nathaniel Lambert put these two facts together and came up with an idea: Why not take all that prayer and direct it at the people who have wronged us? Is it possible that directed prayer might spark forgiveness in those doing the praying -- and in the process preserve relationships?

Lambert and his colleagues decided to test this scientifically in two experiments appearing in Psychological Science, a journal of the Association for Psychological Science. In the first, they had a group of men and women pray one single prayer for their romantic partner's well being. Others -- the experimental controls -- they simply described their partner, speaking into a tape recorder.

Then they measured forgiveness. The scientists defined forgiveness as the diminishing of the initial negative feelings that arise when you've been wronged. Their results showed that those who had prayed for their partner harbored fewer vengeful thoughts and emotions: They were more ready to forgive and move on.

If one single prayer can cause such a striking difference in feelings, then what could prayer over a period of time do for a relationship? In a second study, the researchers had a group of men and women pray for a close friend every day for four weeks. Others simply reflected on the relationship, thinking positive thoughts but not praying for their friend's well-being. They also added another dimension. They used a scale to measure selfless concern for others -- not any particular person but other people generally. They speculated that prayer would increase selfless concern, which in turn would boost forgiveness.

And that's just what they found. But why? How does this common spiritual practice exert its healing effects? The psychological scientists have an idea: Most of the time, couples profess and believe in shared goals, but when they hit a rough patch, they often switch to adversarial goals like retribution and resentment. These adversarial goals shift cognitive focus to the self, and it can be tough to shake that self-focus. Prayer appears to shift attention from the self back to others, which allows the resentments to fade.