Journal of Neuroscience: Why evolutionarily ancient brain areas are important

[ Back to EurekAlert! ] Public release date: 30-Nov-2011
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Contact: Dr. Claudia Distler-Hoffmann
claudia.distler@rub.de
49-234-322-4365
Ruhr-University Bochum

Different brain structures control eye reflexes in the course of life

Structures in the midbrain that developed early in evolution can be responsible for functions in newborns which in adults are taken over by the cerebral cortex. New evidence for this theory has been found in the visual system of monkeys by a team of researchers from the RUB. The scientists studied a reflex that stabilizes the image of a moving scene on the retina to prevent blur, the so-termed optokinetic nystagmus. They found that nuclei in the midbrain initially control this reflex and that signals from the cerebral cortex (neocortex) are only added later on. PD Dr. Claudia Distler-Hoffmann from the Department of General Zoology and Neurobiology and Prof. Dr. Klaus-Peter Hoffmann from the Department of Animal Physiology report in the Journal of Neuroscience.

Why the neocortex needs help

To control sensorimotor functions (e.g. eye movements), the adult brain is equipped with different areas in the neocortex, the evolutionarily youngest part of the cerebrum. "This raises the question, why older subcortical structures in the brain have not lost the functions that can also be controlled by the neocortex" says Hoffmann. The neocortex of primates is, however, not fully functional shortly after birth and therefore cannot control the optokinetic nystagmus. "This is most probably also the case with people" says Distler-Hoffmann. Nevertheless, this reflex works directly after birth.

First the brain stem, then the cerebral cortex

The researchers examined what information controls the optokinetic nystagmus in the first weeks after birth. During the first two weeks, the reflex is controlled by signals from the retina, which are transmitted to two nuclei in the midbrain. The neocortex then adds its information and takes over during the first months of life. The optokinetic reflex, which was studied by the researchers also at the behavioural level, is almost identical under the control of the midbrain and the neocortex. It occurs, for example, when watching a moving scene. First the eyes follow the passing scene, then they move quickly in the opposite direction back to their original position. On this reflex, monkeys and humans build their slow eye tracking movements with which they keep "an eye" on moving objects.

Detecting maldevelopments in the visual system at an early stage

The optokinetic nystagmus changes if the visual system does not develop normally. Lens aberrations, corneal opacity and strabismus affect the reflex. "These findings from research with primates are important for recognizing and treating maldevelopments in the visual system of infants and young children at an early stage" explains Distler-Hoffmann.

###

Bibliographic record

C. Distler, K.-P. Hoffmann (2011): Visual pathway for the optokinetic reflex in infant macaque monkeys, Journal of Neuroscience, doi: 10.1523/JNEUROSCI.4302-11.2011

Further information

PD. Dr. Claudia Distler-Hoffmann, Department of Biology and Biotechnology at the Ruhr-Universitt, 44780 Bochum, Tel.: +49/234/32-24365 claudia.distler@rub.de

Editor

Dr. Julia Weiler


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[ Back to EurekAlert! ] Public release date: 30-Nov-2011
[ | E-mail | Share Share ]

Contact: Dr. Claudia Distler-Hoffmann
claudia.distler@rub.de
49-234-322-4365
Ruhr-University Bochum

Different brain structures control eye reflexes in the course of life

Structures in the midbrain that developed early in evolution can be responsible for functions in newborns which in adults are taken over by the cerebral cortex. New evidence for this theory has been found in the visual system of monkeys by a team of researchers from the RUB. The scientists studied a reflex that stabilizes the image of a moving scene on the retina to prevent blur, the so-termed optokinetic nystagmus. They found that nuclei in the midbrain initially control this reflex and that signals from the cerebral cortex (neocortex) are only added later on. PD Dr. Claudia Distler-Hoffmann from the Department of General Zoology and Neurobiology and Prof. Dr. Klaus-Peter Hoffmann from the Department of Animal Physiology report in the Journal of Neuroscience.

Why the neocortex needs help

To control sensorimotor functions (e.g. eye movements), the adult brain is equipped with different areas in the neocortex, the evolutionarily youngest part of the cerebrum. "This raises the question, why older subcortical structures in the brain have not lost the functions that can also be controlled by the neocortex" says Hoffmann. The neocortex of primates is, however, not fully functional shortly after birth and therefore cannot control the optokinetic nystagmus. "This is most probably also the case with people" says Distler-Hoffmann. Nevertheless, this reflex works directly after birth.

First the brain stem, then the cerebral cortex

The researchers examined what information controls the optokinetic nystagmus in the first weeks after birth. During the first two weeks, the reflex is controlled by signals from the retina, which are transmitted to two nuclei in the midbrain. The neocortex then adds its information and takes over during the first months of life. The optokinetic reflex, which was studied by the researchers also at the behavioural level, is almost identical under the control of the midbrain and the neocortex. It occurs, for example, when watching a moving scene. First the eyes follow the passing scene, then they move quickly in the opposite direction back to their original position. On this reflex, monkeys and humans build their slow eye tracking movements with which they keep "an eye" on moving objects.

Detecting maldevelopments in the visual system at an early stage

The optokinetic nystagmus changes if the visual system does not develop normally. Lens aberrations, corneal opacity and strabismus affect the reflex. "These findings from research with primates are important for recognizing and treating maldevelopments in the visual system of infants and young children at an early stage" explains Distler-Hoffmann.

###

Bibliographic record

C. Distler, K.-P. Hoffmann (2011): Visual pathway for the optokinetic reflex in infant macaque monkeys, Journal of Neuroscience, doi: 10.1523/JNEUROSCI.4302-11.2011

Further information

PD. Dr. Claudia Distler-Hoffmann, Department of Biology and Biotechnology at the Ruhr-Universitt, 44780 Bochum, Tel.: +49/234/32-24365 claudia.distler@rub.de

Editor

Dr. Julia Weiler


[ Back to EurekAlert! ] [ | E-mail | Share Share ]

?


AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.


Source: http://www.eurekalert.org/pub_releases/2011-11/rb-jon113011.php

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Earthquakes: Water as a lubricant

ScienceDaily (Nov. 30, 2011) ? Geophysicists from Potsdam have established a mode of action that can explain the irregular distribution of strong earthquakes at the San Andreas Fault in California. As the science magazine "Nature" reports in its latest issue, the scientists examined the electrical conductivity of the rocks at great depths, which is closely related to the water content within the rocks. From the pattern of electrical conductivity and seismic activity they were able to deduce that rock water acts as a lubricant.

Los Angeles moves toward San Francisco at a pace of about six centimeters per year, because the Pacific plate with Los Angeles is moving northward, parallel to the North American plate which hosts San Francisco. But this is only the average value. In some areas, movement along the fault is almost continuous, while other segments are locked until they shift abruptly several meters against each other releasing energy in strong earthquakes. After the San Francisco earthquake of 1906, the plates had moved by six meters.

The San Andreas Fault acts like a seam of the Earth, ranging through the entire crust and reaching into the mantle. Geophysicists from the GFZ German Research Centre for Geosciences have succeeded in imaging this interface to great depths and to establish a connection between processes at depth and events at surface. "When examining the image of the electrical conductivity, it becomes clear that rock water from depths of the upper mantle, i.e. between 20 to 40 km, can penetrate the shallow areas of the creeping section of the fault, while these fluids are detained in other areas beneath an impermeable layer," says Dr. Oliver Ritter of the GFZ. "A sliding of the plates is supported, where fluids can rise."

These results suggest that significant differences exist in the mechanical and material properties along the fault at depth. The so-called tremor signals, for instance, appear to be linked to areas underneath the San Andreas Fault, where fluids are trapped. Tremors are low-frequency vibrations that are not associated with rupture processes as they are typical of normal earthquakes. These observations support the idea that fluids play an important role in the onset of earthquakes.

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The above story is reprinted from materials provided by Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences.

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Journal Reference:

  1. Michael Becken, Oliver Ritter, Paul A. Bedrosian, Ute Weckmann. Correlation between deep fluids, tremor and creep along the central San Andreas fault. Nature, 2011; 480 (7375): 87 DOI: 10.1038/nature10609

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

Source: http://www.sciencedaily.com/releases/2011/11/111130142245.htm

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Ahead of the Bell: Google shares climb (AP)

NEW YORK ? Shares of Google Inc. got a boost in premarket trading Monday after a Citi Investment Research analyst upgraded the online search leader, citing a recent stock price drop and consistent revenue growth.

The analyst, Mark S. Mahaney, upgraded Google to "Buy" from "Neutral." He'd downgraded the stock in mid-April, but Google's stock price has declined since then while its revenue has grown 28 percent, not counting acquisitions.

The company, he added, has also started to show signs that its profit margin is stabilizing, and its stock price value "has become more attractive as estimates have increased while its share price hasn't. This "is essentially the dip we have been looking for," Mahaney said.

Back in April, the analyst had also cited the growing influence of Facebook as a reason for his downgrade. But in the upgrade, dated Sunday, Mahaney said while he thinks Facebook will continue to influence more traffic on the Internet, the company has no intention of getting into the search business. In addition, Facebook's focus is generating demand through display advertising, while Google's focus is on "demand conversion," that is, turning that demand into clicks and purchases through search ads.

Google's shares climbed $15.08, or 2.7 percent, to $578.08 in premarket trading on Monday.

The stock closed at $563 on Friday, down nearly 4 percent since the beginning of April.

A representative for Google could not immediately be reached for comment on the upgrade.

Source: http://us.rd.yahoo.com/dailynews/rss/search/*http%3A//news.yahoo.com/s/ap/20111128/ap_on_bi_ge/us_google_ahead_of_the_bell

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Video: Is Iran becoming a pressing foreign policy issue?

Meet Nashville's square-dancing Occupiers

While anti-Wall Street protesters in New York, California and elsewhere may often pass their downtime playing drums, meditating or knitting, their Tennessee counterparts could be playing football, hosting a square dance or welcoming opponents with cookies.

Source: http://www.msnbc.msn.com/id/3036697/vp/45483892#45483892

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Kindergarten friendships matter, especially for boys

Wednesday, November 30, 2011

High-quality friendships in kindergarten may mean that boys will have fewer behavior problems and better social skills in first and third grades, said Nancy McElwain, a University of Illinois associate professor of human development and co-author of a study published in a recent issue of Infant and Child Development.

"The findings for girls were different," said Jennifer Engle, lead author of the study. "Overall, teachers reported that girls in the first and third grade had good social skills, regardless of the quality of their kindergarten friendships. Boys, on the other hand, clearly benefited from the good start that early high-quality friendships provide."

Engle said the study was unique in comparing how the presence and quality of children's kindergarten friendships are related to their behavior problems and social skills in kindergarten, first, and third grades.

She noted that friendship quality was important for both boys and girls in kindergarten. Kindergarten kids with high-quality friendships tended to have fewer behavior problems and better social skills than those whose friendships were of low or moderate quality. In contrast, kids who had low-quality kindergarten friendships had more behavior problems during kindergarten.

The differences in friendship quality for boys versus girls didn't show up until the children were older, she said.

"Boys who had no friends in kindergarten had more behavior problems, but not until they had reached first and third grades," she said.

The researchers examined data from 567 children who had participated in the Eunice Kennedy Shriver National Institute of Child Health & Human Development Study of Early Child Care and Youth Development.

Mothers in the study reported on whether their kindergarten child had at least one friend and on the quality of their child's friendships. Researchers then compared the progress of children with no friends, low-quality friendships, average-quality friendships, and high-quality friendships. Teachers provided feedback on children's behavior problems in kindergarten and first and third grades.

"As we expected, high-quality kindergarten friendships that featured cooperation and sharing, taking turns, low levels of hostility, and little destructive conflict, gave children?especially boys?practice in positive interaction, which they demonstrated in grades 1 and 3," Engle said.

How can you help your child learn to be a good friend? McElwain stressed that peers become important as children enter kindergarten. Parents should make an effort to help children, especially boys, make friends at this age through play dates and other social activities, she said.

Children also will likely relate to friends in more positive ways if they have experiences in their family that model positive expectations, caring, and respect.

When children learn to expect that people will respond positively to them, they will be responsive and friendly to others, she noted.

"Those children will be able to handle their emotions better when the going gets rough, and they'll learn how to work through conflicts. Conflict isn't necessarily good or bad; it's a matter of how kids approach disagreements with their friends or parents," she said.

McElwain offered reassurance to parents of friendless kindergartners. "Almost all of those children had made a friend by the time they reached third grade," she said.

###

University of Illinois College of Agricultural, Consumer and Environmental Sciences: http://aces.illinois.edu/

Thanks to University of Illinois College of Agricultural, Consumer and Environmental Sciences for this article.

This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.

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Source: http://www.labspaces.net/115555/Kindergarten_friendships_matter__especially_for_boys

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Divorce Research 2011: Top 11 Findings Of The Year

A September 2011 study published in the Journal of Sexual Medicine found that affairs do more than break hearts -- they may also break penises. Dr. Andrew Kramer studied 16 cases of penile fracture between 2007 and 2011; half of the patients admitted to fracturing their penises during an extramarital affair. "I think that a guy, when he's with a girlfriend or a coworker and he's in a weird place, I think the sex might be different," Dr. Kramer told the Huffington Post. "He's extra excited and maybe he's doing more forceful or frequent thrusting, and the key is that he has less control over the angle that his penis can penetrate and that's what can predispose the fracture." Kramer noted that the paper was "just observational" and that there is no causal relationship between infidelity and penile fracture. It's no surprise that this buzzed-about piece was one of the most popular features on the Huffington Post.

Source: http://www.huffingtonpost.com/2011/11/30/divorce-research-2011_n_1119562.html

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Psychiatric evaluation finds Norway killer insane (AP)

OSLO, Norway ? Confessed mass killer Anders Behring Breivik was insane when he killed 77 people in a bomb and shooting rampage in Norway, and should be sent to a psychiatric ward instead of prison, prosecutors said Tuesday.

A psychiatric evaluation ordered by an Oslo court found that Breivik was "psychotic" during the July 22 attacks ? the country's worst peacetime massacre ? which means he's not mentally fit to be sentenced to prison, prosecutors told reporters.

The conclusions, which will be reviewed by a panel of forensic psychiatrists, contrasted with comments made by the head of that board after the attacks. Dr. Tarjei Rygnestad at the time told who told The Associated Press that it was unlikely that Breivik would be declared legally insane because the attacks were so carefully planned and executed.

"The conclusions of the forensic experts is that Anders Behring Breivik was insane," prosecutor Svein Holden said, adding Breivik was in a state of psychosis during the attacks.

In their report, the experts describe a man "who finds himself in his own delusional universe, where all his thoughts and acts are governed by these delusions," Holden said. "They conclude that Anders Behring Breivik during a long period of time has developed the mental disorder of paranoid schizophrenia, which has changed him and made him into the person he is today."

In Norway, an insanity defense requires that a defendant be in a state of psychosis while committing the crime with which he or she is charged. That means the defendant has lost contact with reality to the point that he's no longer in control of his own actions.

The 243-page report will be reviewed by a panel from the Norwegian Board of Forensic Medicine, which could ask for additional information and add its own opinions.

On Tuesday, Rygnestad, who heads that board told AP that his comments in July were based on "secondary information" and that a person's mental state can only be determined through in-depth analysis. He said he had not read the full report yet.

Source: http://us.rd.yahoo.com/dailynews/rss/topstories/*http%3A//news.yahoo.com/s/ap/20111129/ap_on_re_eu/eu_norway_massacre

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AP IMPACT: More kids skip school shots in 8 states (AP)

ATLANTA ? More parents are opting out of school shots for their kids. In eight states now, more than 1 in 20 public school kindergartners aren't getting all the vaccines required for attendance, an Associated Press analysis found.

That growing trend among parents seeking vaccine exemptions has health officials worried about outbreaks of diseases that once were all but stamped out.

The AP analysis found more than half of states have seen at least a slight rise in the rate of exemptions over the past five years. States with the highest exemption rates are in the West and Upper Midwest.

It's "really gotten much worse," said Mary Selecky, secretary of health for Washington state, where 6 percent of public school parents have opted out.

Rules for exemptions vary by state and can include medical, religious or ? in some states ? philosophical reasons.

Reasons for skipping some school shots vary. Some parents are skeptical that vaccines are essential. Others fear vaccines carry their own risks. Some find it easier to check a box opting out than the effort to get the shots and required paperwork schools demand. Still others are ambivalent, believing in older vaccines but questioning newer shots against, say, chickenpox.

The number of shots is also giving some parents pause. By the time most children are 6, they will have been stuck with a needle about two dozen times ? with many of those shots given in infancy. The cumulative effect of all those shots has not been studied enough, some parents say.

"Many of the vaccines are unnecessary and public health officials don't honestly know what the effect of giving so many vaccines to such small children really are," said Jennifer Margulis, a mother of four and parenting book author in Ashland, Ore.

But few serious problems have turned up over years of vaccinations and several studies have shown no link with autism, a theory from the 1990s that has been widely discredited.

To be sure, childhood vaccination rates remain high overall, at 90 percent or better for several vaccines, including those for polio, measles, hepatitis B and even chickenpox. In many states, exemptions are filed for fewer than 1 percent of children entering school for the first time.

Health officials have not identified an exemption threshold that would likely lead to outbreaks. But as they push for 100 percent immunization, they worry when some states have exemption rates climbing over 5 percent. The average state exemption rate has been estimated at less than half that.

Even more troubling are pockets in some states where exemption rates much higher. In some rural counties in northeast Washington, for example, vaccination exemption rates in recent years have been above 20 percent and even as high as 50 percent.

"Vaccine refusers tend to cluster," said Saad Omer, an Emory University epidemiologist who has done extensive research on the issue.

While parents may think it does no harm to others if their kids skip some vaccines, they are in fact putting others at risk, health officials say. No vaccine is completely effective. If an outbreak begins in an unvaccinated group of children, a vaccinated child may still be at some risk of getting sick.

Studies have found communities with higher exemption rates sometimes are places where measles have suddenly re-emerged in outbreaks. Vaccinated kids are sometimes among the cases, or children too young to be vaccinated. Last year, California had more than 2,100 whooping cough cases, and 10 infants died. Only one had received a first dose of vaccine.

"Your child's risk of getting disease depends on what your neighbors do," said Omer.

And while it seems unlikely that diseases like polio and diphtheria could ever make a comeback to the U.S., immunization expert Dr. Lance Rodewald with the federal Centers for Disease Control and Prevention says it could happen.

"Polio can come back. China was polio free for two decades, and just this year, they were infected from Pakistan, and there is a big outbreak of polio China now. The same could happen here," Rodewald said in an email.

He cited outbreaks of Hib, a disease that can lead to meningitis, among the Amish who don't consistently vaccinate their children. Russia had a huge diphtheria outbreak in the early to mid-1990s, he said, because vaccine coverage declined. "Measles is just visible, but it isn't the only concern," Rodewald said.

For its review, the AP asked state health departments for kindergarten exemption rates for 2006-07 and 2010-11. The AP also looked at data states had previously reported to the federal government. (Most states don't have data for the current 2011-12 school year.)

Alaska had the highest exemption rate in 2010-11, at nearly 9 percent. Colorado's rate was 7 percent, Minnesota 6.5 percent, Vermont and Washington 6 percent, and Oregon, Michigan and Illinois were close behind.

Mississippi was lowest, at essentially 0 percent.

The AP found that vaccine exemptions rose in more than half of states, and 10 had increases over the five years of about 1.5 percentage points or more, a range health officials say is troubling.

Those states, too, were in the West and Midwest ? Alaska, Kansas, Hawaii, Illinois, Michigan, Montana, Oregon, Vermont, Washington and Wisconsin. Arizona saw an increase that put that state in the same ballpark.

Exemption seekers are often middle-class, college-educated white people, but there are often a mix of views and philosophies. Exemption hot spots like Sedona, Ariz., and rural northeast Washington have concentrations of both alternative medicine-preferring as well as government-fearing libertarians.

Opposition to vaccines "is putting people together that normally would not be together," observed Elizabeth Jacobs, a University of Arizona epidemiologist looking at that state's rising exemption rates.

What many of exemption-seeking parents share, however, is a mental calculation that the dangers to their children of vaccine-preventable diseases are less important than the possible harms from vaccine. Or they just don't believe health officials, putting more stock in alternative sources ? often discovered through Internet searches.

"We are being told this by every government official, teacher, doctor that we need vaccines to keep us safe from these diseases. I simply don't believe that to be true. I believe all the diseases in question were up to 90 percent in decline before mass vaccines ever were given. I don't think vaccines are what saved the world from disease. I think effective sewer systems, nutrition, and handwashing (are the reasons)," said Sabrina Paulick, of Ashland, Ore. She's part-time as a caregiver for elderly people in their homes and a mother of a 4-year-old daughter.

Parents say they'd like to reserve the right to decide what vaccinations their children should get, and when. Health officials reply that vaccinations are recommended at an early age to protect children before they encounter a dangerous infection. "If you delay, you're putting a child at risk," said Gerri Yett, a nurse who manages Alaska's immunization program.

Analyzing vaccination exemptions is difficult. States collect data differently; some base their exemption rates on just a small sample of schools ? Alaska, for example ? while others rely on more comprehensive numbers. So the AP worked with researchers at CDC, which statistically adjusted some states' 2010-11 data for a better comparison.

It's also not clear when an exemption was invoked against all vaccines and when it was used to excuse just one or two shots. CDC officials think the second scenario is more common.

Also, states differ on some of the vaccines required and what's needed to get an exemption: Sometimes only a box on a form needs to be checked, while some states want letters or even signed statements from doctors.

Meanwhile, some parent groups and others have pushed legislators to make exemptions easier or do away with vaccination requirements altogether. The number of states allowing philosophical exemptions grew from 15 to 20 in the last decade.

Some in public health are exasperated by the trend.

"Every time we give them evidence (that vaccines are safe), they come back with a new hypothesis" for why vaccines could be dangerous, said Kacey Ernst, another University of Arizona researcher.

The exemption increases have come during a time when the government has been raising its estimates of how many children have autism and related disorders. Some experts suggest that parents have listened intently to that message, with some believing the growing roster of recommended shots must somehow be related.

"I don't understand how other people don't see that these two things are related," said Stacy Allan, a Summit, N.J., mother who filed religious exemptions and stopped vaccinating her three children.

Several parents said that while they believe many health officials mean well, their distrust of the vaccine-making pharmaceutical industry only continues to grow.

"I wouldn't be one to say I am absolutely certain these things are hurting our children," said Michele Pereira, an Ashland mother of two young girls. She is a registered nurse and married to an anesthesiologist. While her daughters have had some vaccinations, they have not had the full recommended schedule.

"I feel like there are enough questions out there that I don't want to take the chance," she said.

___

Associated Press writer Jeff Barnard in Grants Pass, Ore., contributed to this report.

Source: http://us.rd.yahoo.com/dailynews/rss/topstories/*http%3A//news.yahoo.com/s/ap/20111128/ap_on_he_me/us_med_skipping_school_shots

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