Scientists unlock genetics of kids’ brain tumour

May 19, 2010 By Leave a Comment

Washington, May 19 (ANI): An important cancer gene that could lead to more effective drugs being developed to fight pediatric high grade glioma – a disease that currently has a poor prognosis, has been identified.

Gliomas are the most common brain tumour in children.

Scientists at The Institute of Cancer Research (ICR) and The University of Nottingham on behalf of the UK Children’s Cancer and Leukaemia Group, and St Jude Children’s Research Hospital in the US, conducted by far the most comprehensive analysis to date of pediatric high-grade glioma, making a detailed scan of the genome of 78 newly-diagnosed patients.

They compared these pediatric tumour samples with the genome of adult gliomas, looking through 500,000 individual pieces of DNA for variations in the number of copies of each.

In pediatric gliomas, a gene called PDGFRA on chromosome 4q12 was commonly amplified and there were often extra copies of chromosome 1q. These changes are rarely seen in the adult form of the disease.

Clinical differences between gliomas in adults and youth had already been observed, for example growth in disparate areas of the brain, but this is the first study to establish that the underlying genetics differ.

“We found significant differences between the genomes of adult and young people’s gliomas. This is an important finding because it means studies on adult gliomas cannot simply be applied to younger patients, and it has particular implications for drug trials,” said Dr Chris Jones, Leader of the Paediatric Molecular Pathology Team at the ICR.

The researchers also tracked gene activity in 53 of the tumour samples, and compared the results with adult gliomas. Paediatric glioma tumours that did not have the PDGFRA alteration were nevertheless found to have associated genes switched on, suggesting that this biological pathway is a key to the development of this childhood cancer.

The PDGFRA gene carries instructions for making a protein found on the cell surface, which is part of a pathway that helps control cell growth, proliferation and survival — processes that are commonly disrupted in cancer.

“This cancer gene is unusually active in pediatric high-grade gliomas and is likely to be an important drug target,” said Professor Richard Grundy from the Children”s Brain Tumour Research Centre at The University of Nottingham.

In addition, 10 children in the study had glioma that arose after they were treated with radiotherapy to the brain for a previous cancer. Analysis of these children’s tumours revealed they had the gene alterations at even higher frequency than the other cancers studied, which had been triggered by other factors.

The presence of these alterations irrespective of the trigger for the cancer also indicates that they are crucial to glioma development.

The study has been published in the Journal of Clinical Oncology. (ANI)

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Neuroscientists verify how nerve cells distinguish odours

April 29, 2010 By Leave a Comment

Washington, Apr 29 (ANI): Mice in which a certain receptor in the olfactory centre is missing can distinguish similar smells more quickly than mice without genetic manipulation, showed a new study.

The researchers in Professor Dr. Thomas Kuner’s team at the Institute of Anatomy and Cell Biology at Heidelberg University Medical School and Dr. Andreas Schäfer at the Max Planck Institute for Medical Research directly attributed the above behaviour to inhibitor loops between adjacent nerve cells.

The Heidelberg researchers have for the first time confirmed “lateral inhibition” for the olfactory system, from the molecular level to behaviour.

Odours attach to receptors of olfactory cells in nasal mucosa, where they trigger nerve signals.

These signals are processed in what is known as the olfactory bulb, a part of the brain.

In the neuronal network, the incoming signal is converted to a specific electrical pattern that is transmitted to the cerebral cortex and other areas of the brain and is recognized there.

The researchers have now shown for the first time how neuronal processing of olfactory stimuli directly affects the behaviour of test animals.

“We manipulated information processing very specifically in the olfactory bulb and then measured the effect of this genetic manipulation based on reaction time. We were thus able to prove that the test animals, due to localized inhibitor loops, could distinguish very similar odor combinations much faster, yet very reliably,” explained Kuner.

Inhibition via interneurons acts as a kind of filter by amplifying strong stimuli and further weakening weak stimuli, which makes the essential information easier to recognize.

In the test animals, reaction time was reduced by about 50 ms. The time needed by test animals to learn various odors and their memory capability remained unaffected. Recognition of simple odors was also unchanged.

The results of the study were published in the prestigious journal ‘Neuron’. (ANI)

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Gurus can power off your brain

April 28, 2010 By Leave a Comment

The influence that religious gurus have on a person’s thinking power can be all-encompassing.

Areas of the brain responsible for scepticism and vigilance become less active when a person falls under the spell of a charismatic figure, concludes a new study.

The study, which looked at people”s response to prayers spoken by someone purportedly possessing divine healing powers, has been published in Social Cognitive and Affective Neuroscience.

To come up with the conclusion, Uffe Schjødt of Aarhus University in Denmark and colleagues turned to Pentecostal Christians, who believe that some people have divinely inspired powers of healing, wisdom and prophecy.

New Scientist reports, “using functional magnetic resonance imaging (fMRI), Schjødt and his colleagues scanned the brains of 20 Pentecostalists and 20 non-believers while playing them recorded prayers. The volunteers were told that six of the prayers were read by a non-Christian, six by an ordinary Christian and six by a healer. In fact, all were read by ordinary Christians.

“Only in the devout volunteers did the brain activity monitored by the researchers change in response to the prayers. Parts of the prefrontal and anterior cingulate cortices, which play key roles in vigilance and scepticism when judging the truth and importance of what people say, were deactivated when the subjects listened to a supposed healer.

“Activity diminished to a lesser extent when the speaker was supposedly a normal Christian.”

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Gurus can power off your brain

April 28, 2010 By Leave a Comment

The influence that religious gurus have on a person’s thinking power can be all-encompassing.

Areas of the brain responsible for scepticism and vigilance become less active when a person falls under the spell of a charismatic figure, concludes a new study.

The study, which looked at people”s response to prayers spoken by someone purportedly possessing divine healing powers, has been published in Social Cognitive and Affective Neuroscience.

To come up with the conclusion, Uffe Schjødt of Aarhus University in Denmark and colleagues turned to Pentecostal Christians, who believe that some people have divinely inspired powers of healing, wisdom and prophecy.

New Scientist reports, “using functional magnetic resonance imaging (fMRI), Schjødt and his colleagues scanned the brains of 20 Pentecostalists and 20 non-believers while playing them recorded prayers. The volunteers were told that six of the prayers were read by a non-Christian, six by an ordinary Christian and six by a healer. In fact, all were read by ordinary Christians.

“Only in the devout volunteers did the brain activity monitored by the researchers change in response to the prayers. Parts of the prefrontal and anterior cingulate cortices, which play key roles in vigilance and scepticism when judging the truth and importance of what people say, were deactivated when the subjects listened to a supposed healer.

“Activity diminished to a lesser extent when the speaker was supposedly a normal Christian.”

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Psychopathic behaviour might be linked to frontal lobe dysfunction

April 28, 2010 By Leave a Comment

Washington, April 28 (ANI): Psychopathic behaviour might be associated with frontal lobe dysfunction, suggests a new Israeli study.

One previous explanation for psychopathic tendencies has been a reduced capacity to make inferences about the mental states of other people, an ability known as Theory of Mind (ToM).

On the other hand, psychopaths are also known to be extremely good manipulators and deceivers, which would imply that they have good skills in inferring the knowledge, needs, intentions, and beliefs of other people.

Therefore, it has been suggested recently that ToM is made up of different aspects: a cognitive part, which requires inferences about knowledge and beliefs, and another part which requires the understanding of emotions.

Dr Simone Shamay-Tsoory, from the University of Haifa in Israel, along with colleagues from The Shalvata Mental Health Care Center and the Rambam Medical Center, tested the hypothesis that impairment in the emotional aspects of these abilities may account for psychopathic behaviour.

Earlier research from the same group had shown that patients with damage to the frontal lobes of the brain lack some of the emotional aspects of Theory of Mind, so they speculated that psychopathy may also be linked to frontal lobe dysfunction.

The emotional and cognitive aspects of Theory of Mind abilities were examined for participants in the new study, which consisted of a number of different groups: criminal offenders, who had been diagnosed as having antisocial personality disorder with highly psychopathic tendencies, patients with damage to the frontal lobes of the brain, patients with damage to other areas of the brain, and healthy control subjects.

The pattern of impairments in the psychopathic participants showed a remarkable resemblance to those in the participants with frontal lobe damage, suggesting that an underlying cause of the behavioural disturbances observed in psychopathy may be dysfunction in the frontal lobes.

The findings of the study have appeared in the May 2010 issue of Elsevier”s Cortex. (ANI)

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Religious gurus have the power to switch off your brain

April 28, 2010 By Leave a Comment

London, Apr 28 (ANI): Areas of the brain responsible for scepticism and vigilance become less active when a person falls under the spell of a charismatic figure, concludes a new study.

The study, which looked at people”s response to prayers spoken by someone purportedly possessing divine healing powers, has been published in Social Cognitive and Affective Neuroscience.

To come up with the conclusion, Uffe Schjødt of Aarhus University in Denmark and colleagues turned to Pentecostal Christians, who believe that some people have divinely inspired powers of healing, wisdom and prophecy.

New Scientist reports, “using functional magnetic resonance imaging (fMRI), Schjødt and his colleagues scanned the brains of 20 Pentecostalists and 20 non-believers while playing them recorded prayers. The volunteers were told that six of the prayers were read by a non-Christian, six by an ordinary Christian and six by a healer. In fact, all were read by ordinary Christians.

“Only in the devout volunteers did the brain activity monitored by the researchers change in response to the prayers. Parts of the prefrontal and anterior cingulate cortices, which play key roles in vigilance and scepticism when judging the truth and importance of what people say, were deactivated when the subjects listened to a supposed healer.

“Activity diminished to a lesser extent when the speaker was supposedly a normal Christian.” (ANI)

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Even pain-associated words hurt

March 31, 2010 By Leave a Comment

Washington, Mar 31 (ANI): It is not only the painful memories and associations that set our pain memory on the alert, pain-associated words too pinch in the brain, researchers have shown.

“Even verbal stimuli lead to reactions in certain areas of the brain”, claims Dr. Thomas Weiss from the Friedrich-Schiller-University Jena. As soon as we hear words like “tormenting”, “gruelling” or “plaguing”, exactly those areas in the brain are being activated which process the corresponding pain.

In the new study, the scientist and his team from the Dept. of Biological and Clinical Psychology have examined how pain-associated words are processed in the brain.

The psychologists from Jena University were able to examine this phenomenon using functional magnetic resonance tomography (fMRT).

In their study they investigated how healthy subjects process words associated with experiencing pain. In order to prevent reactions based on a plain negative affect the subjects were also confronted with negatively connotated words like “terrifying”, “horrible” or “disgusting” besides the proper pain words.

“Subject performed two tasks”, explains Maria Richter, doctoral candidate in Weiss”s team.

“In a first task, subjects were supposed to imagine situations which correspond to the words”, the Jena psychologist says. In a second task, subjects were also reading the words but they were distracted by a brain-teaser.

“In both cases we could observe a clear activation of the pain matrix in the brain by pain-associated words”, Maria Richter states. Other negatively connotated words, however, do not activate those regions. Neither for neutrally nor for positively connotated words comparable activity patterns could be examined.

“These findings show that words alone are capable of activating our pain matrix”, underlines Prof. Weiss.

To save painful experiences is of biological advantage since it allows us to avoid painful situations in the future, which might be dangerous for our lives. “However, our results suggest as well that verbal stimuli have a more important meaning than we have thought so far.”

For the Jena psychologist the question remains open which role the verbal confrontation with pain plays for chronic pain patients. “They tend to speak a lot about their experiencing of pain to their physician or physiotherapist”, Maria Richter says.

It is possible that those conversations intensify the activity of the pain matrix in the brain and therefore intensify the pain experience. This is what the Jena psychologists want to clarify in another study. (ANI)

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Some women have ‘bad mum’ switch

March 26, 2010 By Leave a Comment

Melbourne, Mar 26 (ANI): Some women are born with a bad mother switch, says a new study.

Researchers at Richmond University in Virginia said that women develop a set of “maternal neurons” that operate like “bad mother/good mother” switches in the brain.

Using brain-scanning techniques, they have identified a cluster of brain cells, created during pregnancy and “switched on” after birth, that appear to correlate with good or bad parenting behaviours.

“We believe that a certain number of these ”maternal neurons” need to be ”switched on” for good mothering to take place,” News.com.au quoted Professor Craig Kinsley, whose research has so far been limited to rodents and small mammals, as saying.

“Our research showed that the mothers with fewer than this number of ‘maternal neurons’ tended to neglect or abuse their offspring, while those animals with the lowest numbers actually savaged or killed their own young,” he added.

Similar techniques could soon be used to identify human mothers with the capacity to abuse their children.

A team at Yale University is already using brain scans to study the areas of the brain that drive good and bad mothering.

“We have identified certain areas of the brain where there is a correlation between the level of neuron activity and measures of ‘adequate’ and ‘inadequate’ parenting,” said Professor James Swain.

However, not everyone is supporting the idea.

“There is no single factor that determines maternal behaviour,” said Professor Alison Fleming.

“The idea that a woman’s brain is ‘hard-wired’ in such a way that she will abuse her children and that it is not within her power to refrain from doing wrong is based on a misunderstanding of neuro-anatomy. All behaviour is dictated by the brain, but the brain is formed in interaction with our environment,” he added.

Fleming is also concerned that the new research into maternal neurons could be used to argue diminished responsibility for those who abuse their children.

But Kinsley disagrees, saying: “We are all a slave to our brain function. An abusive mother has something malfunctioning in the brain so, in that respect, her behavior is beyond her control.” When it comes to studying the brain, questions of “bad” and “good” need to be replaced with notions of “broken” and “fixed”, he said.

“But it’s not a question of whether we excuse a certain behaviour. The aim of our research is to identify brain malfunctions so we can work towards fixing them.” (ANI)

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Humans better than monkeys at understanding tools’ use

September 17, 2009 By Leave a Comment

London, Sep 17 (ANI): Humans have an edge over monkeys when it comes to using tools to solve a multitude of problems, according to a study.

In the study, a brain region in humans lighted up on seeing tools being used, but the same effect could not be observed in macaque monkeys.

Thus, the researchers concluded that, in humans, a particular brain region responds to tool use.

This could have enabled early humans to understand how and why a tool worked, because it gave them early insights into cause and effect.

With this knowledge in hand, they could work out in advance how tools could be used or modified to solve a multitude of new problems.

On the other hand, monkeys can be taught to use a tool to obtain a reward, but they have little or no insight into the underlying concepts and forces that make it work.

“It meant humans could understand things much more rapidly,” New Scientist quoted Guy Orban of the Catholic University of Leuven in Belgium, the head of the team that discovered the uniquely human area, as saying.

“To get an associative understanding between tool and reward, monkeys must do things many times to learn by trial and error. But once understanding was genetically programmed to be there, humans could begin solving each new problem from a much higher level,” he added.

The researchers identified the unique area, called the anterior supramarginal gyrus (aSMG), through experiments in which 47 people and five rhesus monkeys watched videos of simple tools being used while their brains were scanned with fMRI.

Two of the monkeys had been trained to obtain rewards beyond their reach by using either a rake or a pair of pliers.

The researchers observed that exactly the same areas of the brain became active in people and monkeys when they watched footage of hands simply grasping tools.

But when they watched videos of tools actually being used, the aSMG became active in the humans alone. It was silent even in the two trained monkeys’.

According to the researchers, the region may be specific to understanding cause and effect in tools alone: other brain regions have been seen to be active in more general studies of “cause and effect”.

“This is only the first step towards use of tools,” said Orban.

The study has been published in the Journal of Neuroscience. (ANI)

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How some people maintain weight loss, others don’t

September 17, 2009 By Leave a Comment

Washington, Sep 16 (ANI): Ever wondered how some people successfully maintain a significant weight loss, while others tend to regain the weight? Well, researchers at The Miriam Hospital attribute such tendencies to a difference in brain activity patterns.

The researchers showed that when individuals who had kept the weight off for several years were shown pictures of food, they were more likely to engage the areas of the brain associated with behavioural control and visual attention, as compared to obese and normal weight participants.

The findings of the study suggest that successful weight loss maintainers may learn to respond differently to food cues.

“Our findings shed some light on the biological factors that may contribute to weight loss maintenance. They also provide an intriguing complement to previous behavioral studies that suggest people who have maintained a long-term weight loss monitor their food intake closely and exhibit restraint in their food choices,” said lead author Dr. Jeanne McCaffery.

Long-term weight loss maintenance continues to be a major problem in obesity treatment.

Participants in behavioural weight loss programs lose an average of 8 to 10 percent of their weight during the first six months of treatment, and will maintain approximately two-thirds of their weight loss after one year.

However, despite intensive efforts, weight regain appears to continue for the next several years, with most patients returning to their baseline weight after five years.

The researchers used functional magnetic resource imaging (fMRI) to study the brain activity of three groups- 18 individuals of normal weight, 16 obese individuals (defined as a body mass index of at least 30), and 17 participants who have lost at least 30 lbs and have successfully maintained that weight loss for a minimum of three years.

When the participants were shown pictures of food items after a four-hour fast, it was found that those in the successful weight loss maintenance group responded differently to these pictures compared to the other groups.

Specifically, researchers observed strong signals in the left superior frontal region and right middle temporal region of the brain – a pattern consistent with greater inhibitory control in response to food images and greater visual attention to food cues.

“It is possible that these brain responses may lead to preventive or corrective behaviors – particularly greater regulation of eating – that promote long-term weight control. However, future research is needed to determine whether these responses are inherent within an individual or if they can be changed,” said McCaffery.

The study has been published in the American Journal of Clinical Nutrition. (ANI)

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Scientists develop robotic hand that ‘restores sense of touch’

September 10, 2009 By Leave a Comment

London, Sept 10 (ANI): The first robotic hand to give amputees a sense of touch has been created by Swedish scientists.

When pressed against an object the 40 sensors in the Smarthand get activated. It also has four motors, which move the thumb and fingers.

They stimulate nerves in the arm to activate the appropriate part of the brain. This allows patients to feel objects they are holding, reports Sky News.

“It’s a feeling I have not had in a long time,” said Robin af Ekenstam, the first amputee to try the hand.

“When I grab something tightly I can feel it in the fingertips. It’s strange since I don’t have them any more! It’s amazing,” he added.

The motors are connected to nerves in the arm that once moved Robin’s real digits. Thanks to the “hand”, he’s able to pick up a plastic water bottle, without crushing it, and pour himself a drink.

Professor Goran Lundborg, a surgeon at Malmo University Hospital, said the artificial hand was a significant advance.

“If you find the right spot the correct areas of the brain cortex will be activated. If you put pressure on the index finger of the artificial hand then the index finger area of the brain will be activated,” he said.

The research is funded by the European Commission. (ANI)

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How monkeys decide to explore new options

September 5, 2009 By Leave a Comment

Washington, Sep 5 (ANI): Researchers at Duke University Medical Center have used brain scans in monkeys to predict when monkeys decide if they want to switch from exploiting a known resource to exploring newer options.

Such a trade-off is easy for many, but not for those with conditions such as Alzheimer’s disease or obsessive-compulsive disorder who are trapped in simple routines.

“Humans aren’t the only animals who wonder if the grass is greener elsewhere, but it’s hard to abandon what we know in hopes of finding something better,” said Dr. John Pearson.

“Studies like this one help reveal how the brain weighs costs and benefits in making that kind of decision. We suspect that such a fundamental question engages many areas of the brain, but this is one of the first studies to show how individual neurons can carry signals for these kinds of strategic decisions,” he added.

The researchers analysed how nerve cells fired in a part of the brain known as the posterior cingulate cortex as the monkeys were offered a selection of rewards.

Generally, these neurons fired more strongly when monkeys decided to explore new alternatives.

The monkeys started with four rewards to choose from, each a 200 microliter cup of juice.

Later, the four targets began to slowly change in value, becoming larger or smaller. The monkeys were free to explore the other targets or stay with the initial target, whose value they knew for certain.

The animals had to select an option to learn its current value and integrate this information with their knowledge of the chances of getting more juice at a different target.

The researcher studied individual neurons and were able to predict which strategy the monkey would employ.

“These data are interesting from a human health perspective, because the posterior cingulate cortex is the most metabolically active part of the brain when we are daydreaming or thinking to ourselves, and it is also one of the first parts of the brain to show damage in Alzheimer’s disease,” said Dr. Michael Platt.

“People with Alzheimer’s become set in their ways and don’t explore as much, which may be because this part of the brain is damaged. Likewise, in people with obsessive-compulsive disorder, they can become fixed on certain activities or patterns of activity and can’t disengage from them, which may also relate to changes in this part of the brain that renders them mentally unable to switch gears between exploring and exploiting,” he added.

Such brain functions could be crucial to the flexible adaptation of strategy in response to changing environments, said Pearson.

The study has been published in the latest issue of Current Biology. (ANI)

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Playing Tetris could boost brain power

September 2, 2009 By Leave a Comment

London, September 2 (ANI): Playing Tetris may help increase brain efficiency, says a new research.

Researchers from Mind Research Network in Albuquerque, New Mexico, examined the effects of practice in the brain using two image techniques.

Dr. Rex Jung and Dr. Richard Haier, co-investigators in the Tetris study, made use of brain imaging and Tetris to see if practice makes the brain efficient because it increases gray matter.

Jung, a clinical neuropsychologist, said: “One of the most surprising findings of brain research in the last five years was that juggling practice increased gray matter in the motor areas of the brain.

“We did our Tetris study to see if mental practice increased cortical thickness, a sign of more gray matter. If it did, it could be an explanation for why previous studies have shown that mental practice increases brain efficiency.

“More gray matter in an area could mean that the area would not need to work as hard during Tetris play.”

Haier, lead author of a 1992 research that discovered practicing Tetris led to greater brain efficiency, also added: “We were excited to see cortical thickness differences between the girls that practiced Tetris and those that did not.

“But, it was surprising that these changes were not where we saw more efficiency. How a thicker cortex and increased brain efficiency are related remains a mystery.”

The study has been published in the open access journal BMC Research Notes. (ANI)

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Obese people ‘at greater Alzheimer’s risk’

August 26, 2009 By Leave a Comment

Washington, Aug 26 (ANI): Here’s some discouraging news for obese people: a new report has found that fat people are at greater risk for developing Alzheimer’s.

In the current online edition of the journal Human Brain Mapping, Paul Thompson, senior author and a UCLA professor of neurology, and lead author Cyrus A. Raji, a medical student at the University of Pittsburgh School of Medicine, and colleagues compared the brains of people who were obese, overweight, and of normal weight, to see if they had differences in brain structure; that is, did their brains look equally healthy.

They found that obese people had 8 percent less brain tissue than people with normal weight, while overweight people had 4 percent less tissue.

“That’s a big loss of tissue and it depletes your cognitive reserves, putting you at much greater risk of Alzheimer’s and other diseases that attack the brain,” said Thompson. But you can greatly reduce your risk for Alzheimer’s, if you can eat healthily and keep your weight under control,” he added.

To reach the conclusion, researchers used brain images from an earlier study called the Cardiovascular Health Study Cognition Study. Scans were selected of 94 elderly people in their 70s who were healthy not cognitively impaired-five years after the scan was taken. To define the weight categories, they used the Body Mass Index (BMI), the most widely used measurement for obesity. Normal weight people were defined as having a BMI between 18.5-25; overweight people between 25-30, and obese people greater than 30.

The researchers then converted the scans into detailed three-dimensional images using tensor-based morphometry, a neuroimaging method that offers high resolution mapping of anatomical differences in the brain.

In looking at both grey matter and white matter of the brain, they found that the people defined as obese had lost brain tissue in the frontal and temporal lobes, areas of the brain critical for planning and memory, and in the anterior cingulate gyrus (attention and executive functions), hippocampus (long term memory) and basal ganglia (movement). Overweight people showed brain loss in the basal ganglia, the corona radiata, white matter comprised of axons, and the parietal lobe (sensory lobe).

“The brains of obese people looked 16 years older than the brains of those who were lean, and in overweight people looked eight years older,” says Thompson.

“It seems that along with increased risk for health problems such as type 2 diabetes and heart disease, obesity is bad for your brain: we have linked it to shrinkage of brain areas that are also targeted by Alzheimer’s,” said Pittsburgh’s Raji.

“But that could mean exercising, eating right and keeping weight under control can maintain brain health with aging and potentially lower the risk for Alzheimer’s and other dementias,” the expert added. (ANI)

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New ‘brain-reading’ method can uncover a person’s mental state

July 29, 2009 By Leave a Comment

Washington, July 28 (ANI): Researchers at Rutgers University in Newark and the University of California, Los Angeles, have developed a highly accurate method to peer into the brain, which can help uncover a person’s mental state and determine what sort of information is being processed before it reaches conscious awareness.

The discovery of this new window into the brain has provided scientists with a means to develop a more accurate model of the inner functions of the brain.

Led by Stephen Jose Hanson, a professor of Psychology at Rutgers, the study has provided direct evidence that a person’s mental state can be predicted with a high degree of accuracy through functional magnetic resonance imaging (fMRI).

The research has also suggested that a more comprehensive approach is needed to map brain activity, and that the widely held belief that localized areas of the brain are responsible for specific mental functions is misleading and incorrect.

In their analysis of global brain activity, the researchers found that different processing tasks have their own distinct pattern of neural connections stretching across the brain, similar to the fingerprints that distinctively identify each of us.

However, instead of being a static pattern, the brain is able to arrange and rearrange the connections based on the mental task being undertaken.

“You can’t just pinpoint a specific area of the brain, for example, and say that is the area responsible for our concept of self or that part is the source of our morality.

It turns out the brain is much more complex and flexible than that. It has the ability to rearrange neural connections for different functions. By examining the pattern of neural connections, you can predict with a high degree of accuracy what mental processing task a person is doing,” said Hanson.

The findings open up the possibility of categorizing a multitude of mental tasks with their unique pattern of neural circuitry, and also represent a potential first, early step in developing a means for identifying higher-level mental functions, such as ‘lying’ or abstract reasoning.

They potentially also could pave the way for earlier diagnosis and better treatment of mental disorders, such as autism and schizophrenia, by offering a means for identifying very subtle abnormalities in brain activity and synchrony.

The findings provide a more accurate direction for mapping the effective connectivity of the brain.

Known as the Connectome Project, the goal of researchers involved in the work is to provide a complete map of the neural circuitry of the central nervous system.

The study involved 130 participants, each of whom performed a different mental task, ranging from reading, to memorizing a list, to making complex decisions about whether to take monetary risks, while being scanned using fMRI.

By analysing the participants’ fMRI data against classifications developed from the fMRIs of other individuals, the researches could identify which of eight tasks participants were involved in with more than 80 percent accuracy.

The researchers could also identify what class of objects (faces, houses, animals, etc.) a person was viewing before he or she could report that information by analysing the pattern of brain activity at the back of the brain where information is processed and then conveyed towards the frontal regions associated with awareness.

“What our research shows is that if you want to understand human cognitive function, you need to look at system-wide behaviour across the entire brain. You can’t do it by looking at single cells or areas. You need to look at many areas of the brain to even understand the simplest of functions,” explained Hanson.

The study appears in a forthcoming issue of Psychological Science. (ANI)

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Superior language skills in 20s may protect against Alzheimer’s

July 10, 2009 By Leave a Comment

Washington, July 9 (ANI): People with greater language abilities in early adulthood may be less likely to develop Alzheimer’s disease later in life, according to a new research.

A team from Johns Hopkins University studied the brains of 38 Catholic nuns after death and found that those with good language skills early in life were less likely to have memory problems – even if their brains showed signs of dementia damage.

“A puzzling feature of Alzheimer’s disease is how it affects people differently,” said study author Juan C. Troncoso, MD, with Johns Hopkins University in Baltimore.

“One person who has severe plaques and tangles, the telling signs of Alzheimer’s disease in their brains, may show no symptoms affecting their memory. Another person with those same types of plaques and tangles in the same areas of the brain might end up with a full-blown case of Alzheimer’s disease. We looked at how language ability might affect the onset of symptoms,” Troncoso added.

In the study, scientists determined two groups: women with memory problems and Alzheimer’s disease hallmarks in the brain and women with normal memory with or without signs of Alzheimer’s disease in the brain.

The researchers analyzed essays that 14 participants wrote as they entered the convent in their late teens or early 20′s.

They studied the average number of ideas expressed for every 10 words. The analysis also measured how complex the grammar was in each essay.

The study found that language scores were 20 percent higher in the women without memory problems compared to those with memory problems. The grammar score, however, did not show any difference between the two groups.

“Despite the small number of participants in this portion of the study, the finding is a fascinating one.

Our results show that an intellectual ability test in the early 20s may predict the likelihood of remaining cognitively normal five or six decades later, even in the presence of a large amount of Alzheimer’s disease pathology,” Troncoso said.

The study has been published in the July 9, 2009, online issue of Neurology. (ANI)

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Decision-making brain region also deciphers different phonetic sounds

July 1, 2009 By Leave a Comment

Washington, July 1 (ANI): A collaborative team of researchers from Brown University and the University of Cincinnati have found that a front portion of the brain, which handles decision-making, also helps decipher different phonetic sounds.

Writing about their findings in the journal Psychological Science, the researchers have revealed that this section of the brain is called the left inferior frontal sulcus.

They say that this section treats different pronunciations of the same speech sound-such as a ‘d’ sound-the same way.

The researchers say that in determining this, they have solved a mystery.

MRI studies showed that test subjects reacted to different sounds – ta and da, for example – but appeared to recognize the same sound even when pronounced with slight variations. These five sounds are the same, but the fifth (right) has a slightly different pronunciation.

“No two pronunciations of the same speech sound are exactly alike. Listeners have to figure out whether these two different pronunciations are the same speech sound such as a ‘d’ or two different sounds such as a ‘d’ sound and a ‘t’ sound,” said Emily Myers, assistant professor (research) of cognitive and linguistic sciences at Brown University.

Lead researcher Sheila Blumstein, the Albert D. Mead Professor of Cognitive and Linguistic Sciences at Brown, said that the findings provided a window into how the brain processes speech.

“No one has shown before what areas of the brain are involved in these decisions. As human beings we spend much of our lives categorizing the world, and it appears as though we use the same brain areas for language that we use for categorizing non-language things like objects,” said Blumstein.

The research team studied 13 women and five men, ages 19 to 29. All were brought into an MRI scanner at Brown University’s Magnetic Resonance Facility, so that the researchers could measure blood flow in response to different types of stimuli.

Subjects were asked to listen to repetitive syllables in a row as they lay in the scanner. The sounds were derived from recorded, synthesized speech. Initially subjects would hear identical “dah” or “tah” sounds – four in a row – which would reduce brain activity because of the repetition. The fifth sound could be the same or a different sound.

The study showed that the brain signal in the left inferior frontal sulcus changed when the final sound was a different one. But if the final sound was only a different pronunciation of the same sound, the brain’s response remained steady.

According to Myers and Blumstein, the study matters in the bid to understand language and speaking and how the brain is able to understand certain sounds and pronunciations.

“What these results suggest is that [the left inferior frontal sulcus] is a shared resource used for both language and non-language categorization,” Blumbstein said. (ANI)

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Novel peptide nanoparticles to fight fatal brain infections

June 29, 2009 By Leave a Comment

London, June 29 (ANI): New peptide nanoparticles developed by researchers at the Institute of Bioengineering and Nanotechnology (IBN) of Singapore could pave the way for new methods of drug and gene delivery for the treatment of meningitis and drug-resistant bacteria and fungal infections.

The stable bioengineered nanoparticles effectively seek out and destroy bacteria and fungal cells that could cause fatal infections and are highly therapeutic.

Major brain infections like meningitis and encephalitis are leading causes of death, hearing loss, learning disability, and brain damage in patients.

Conversely, the peptide nanoparticles contain a membrane-penetrating component that enables them to pass through the blood brain barrier to the infected areas of the brain that require treatment.

IBN’s peptide nanoparticles can traverse the blood brain barrier, thereby offering a superior alternative to existing treatments for brain infections.

The brain membrane is impenetrable to most conventional antibiotics because the molecular structure of most drugs is too big to enter the membrane.

“Our treatment damages the structure of the pathogen and literally breaks it apart,” Nature magazine quoted Dr. Yiyan Yang, group leader at IBN, as saying.

He added: “Our oligopeptide has a unique chemical structure that forms nanoparticles with membranepenetrating components on their surface. These nanoparticles can easily enter bacteria, yeast or fungal cells and destabilize them to cause cell death. For example, the nanoparticles cause damage to bacteria cell walls and prevent further bacterial growth.”

The researchers have demonstrated that these engineered peptide nanoparticles have high anti-microbial activity and are highly effective in killing microbes.

In addition, the peptide nanoparticles are more powerful in inhibiting the growth of fungal infections than conventionally available anti-fungal drugs such as fluconazole and amphotericin B.

“We are able to kill bacteria better than conventional antibiotics. By attacking the cellular structure of the microbes, our nanoparticles can be used to successfully combat persistant bacterial infections,” added IBN scientist Dr. Lihong Liu.

Pre-clinical tests have shown that IBN’s peptide nanoparticles are biocompatible, and cause no damage to the liver or kidneys at tested doses.

Highly anti-infective, the therapeutic doses of the peptide nanoparticles are expected to be safe for use because they also do not damage red blood cells.

The study has been published in the journal Nature Nanotechnology. (ANI)

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How brain waves fire in unison while paying attention

May 29, 2009 By Leave a Comment

Washington, May 29 (ANI): While the neurons in human brains are known to start firing in unison when a person pays attention, scientists have now found the brain centre that controls this neural chorus.

MIT neuroscientists have found that neurons in the prefrontal cortex – the brain’s planning centre – fire in unison and send signals to the visual cortex to do the same, generating high-frequency waves that oscillate between these distant brain regions like a vibrating spring.

The waves, also known as gamma oscillations, have long been associated with cognitive states like attention, learning, and consciousness.

“We are especially interested in gamma oscillations in the prefrontal cortex because it provides top-down influences over other parts of the brain. We know that the prefrontal cortex is affected in people with schizophrenia, ADHD and many other brain disorders, and that gamma oscillations are also altered in these conditions.

Our results suggest that altered neural synchrony in the prefrontal cortex could disrupt communication between this region and other areas of the brain, leading to altered perceptions, thoughts, and emotions,” said senior author Robert Desimone.

The researchers explained this neural synchrony by using the analogy of a crowded party with people talking in different rooms-if individuals raise their voices at random, the noise just becomes louder.

But if a group of individuals in one room chant together in unison, the next room is more likely to hear the message, and if the people in the other room respond in the same way, the two rooms can communicate.

In the study, the researchers looked for patterns of neural synchrony in two “rooms” of the brain associated with attention – the frontal eye field (FEF) within the prefrontal cortex and the V4 region of the visual cortex.

By training two macaque monkeys to watch a monitor displaying multiple objects, and to concentrate on one of the objects, the researchers monitored neural activity in both the above regions of the brain.

They analysed the timing of the neural activity and found that the prefrontal cortex became engaged by attention first, followed by the visual cortex-as if the prefrontal cortex commanded the visual region to snap to attention.

The delay between neural activity in these areas during each wave cycle revealed the speed at which signals travel from one region to the other, which indicated that the two brain regions were talking to one another.

The study has been published in the journal Science. (ANI)

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Meditation helps build stronger brains

May 13, 2009 By Leave a Comment

Washington, May 13 (ANI): A new study has confirmed what many people believed: meditation helps increase gray matter.

A research team from University of California, Los Angeles scanned the brains of people who meditate and found that certain regions in the brains of long-term meditators were larger than in a similar control group.

Meditators showed significantly larger volumes of the hippocampus and areas within the orbito-frontal cortex, the thalamus and the inferior temporal gyrus – all known for regulating emotions.

“We know that people who consistently meditate have a singular ability to cultivate positive emotions, retain emotional stability and engage in mindful behaviour,” said Eileen Luders, lead author and a postdoctoral research fellow at the UCLA Laboratory of Neuro Imaging.

“The observed differences in brain anatomy might give us a clue why meditators have these exceptional abilities,” Luders added.

During the study, the research team looked at 44 people. Half were asked to practice various forms of meditation such as Zazen, Samatha and Vipassana and the other half acted as the control group.

More than half of all the meditators said that deep concentration was an essential part of their practice, and most meditated between 10 and 90 minutes every day.

The brains of the meditators showed larger volumes of the right hippocampus and increased gray matter in the right orbito-frontal cortex, the right thalamus and the left inferior temporal lobe.

Because these areas of the brain are closely linked to emotion, Luders said, “these might be the neuronal underpinnings that give meditators’ the outstanding ability to regulate their emotions and allow for well-adjusted responses to whatever life throws their way.”

The study is published in the journal NeuroImage. (ANI)

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