Thursday, August 2, 2012

Parkinson's eye damage hope

Vaaka_Eye_iStock Recent studies by the team show near infra-red light can protect the retina of the eye from toxins which attack its nerve cells. Vision scientists have discovered a new avenue for the treatment of vision loss, one of complications of Parkinson’s disease.

Gentle, non-invasive treatment with a soft infra-red light can potentially protect and heal the damage that occurs to the human retina in in Parkinson’s disease, says Professor Jonathan Stone from The Vision Centre and The University of Sydney.

“Near infra-red light (NIR) treatment has long been known to promote the healing of wounds in soft tissues such as skin. Our recent studies are showing that it can also protect the retina of the eye from toxins which attack its nerve cells,” Professor Stone says.

“We have been studying a mouse ‘model’ of Parkinson’s disease, in which such a toxin is used to create a Parkinson-like condition. The toxin targets brain cells which use a particular signalling molecule called dopamine, and the infrared light – in the right dose and with the right timing – blocks the toxic effect.”

The toxin also kills certain key retinal cells which use dopamine which are important in giving sharpness to the retina’s coding of visual images. However infrared light also protects these retinal cells and reduces the damage.

“This protection or rescue of neurones in the brain – and as we know now, in the retina – is better than the best established treatments for Parkinson’s disease,” Professor Stone says. “The challenge now is to translate these findings, made in mouse models, to human patients suffering from Parkinson’s disease.”

The research has also raised important new questions, he adds. “How, for example, does the infrared light create this protection? The answer seems to be that the radiation reverses damage to the cells’ machinery for the production of the energy it needs, from oxygen. With their energy production restored, damaged cells repair themselves, and resume function.

“Does the radiation work if given before the cell is damaged, or only after it is damaged? The rescue effect is there either way”, says Professor Stone. “We have much to learn about the mechanism and its timing, but these initial observations are encouraging.

“As to how soon it can be applied clinically, there are already dozens of clinical trial published, using infrared light for soft tissue wound healing and for pain relief. Small but good quality clinical trials have been reported for human vision, in age-related macular degeneration, and for stroke damage to the brain.

“Our new results suggest that infra-red radiation will be effective in Parkinson’s disease. Because the radiation is effective at low intensities, with no known toxicity, there are few barriers if any to trials in humans.

”Diseases like Parkinson’s are seriously debilitating; for the individual the need is immediate. There is every reason for trials to be carried out as soon as possible.”

As to the potential benefits for Parkinson’s patients, he says: “Principally, we anticipate there would be a preservation of acuity, the clarity with which we can see detail and contours in the visual world. The same treatment should be protective for the brain as well, preventing or slowing the otherwise relentless progress of the disease. As always, we will need rigorous trials, to know what can be achieved.”

Finally, he says, it is no surprise that the same treatment works for both the brain and the retina: “The retina of the eye is really part of the brain – the only part outside the skull. It has to be outside the skull, so it can function as an eye. In many ways the retina is the most accessible part of the brain, and many discoveries about the brain have begun in the retina.”

“Parkinson’s is a double-whammy disease,” says Professor Stone. “Our dream is turn back both the damage to the brain, and the damage to the retina. Increasingly, this seems possible.”

The study “Survival of Dopaminergic Amacrine Cells after Near-Infrared Light Treatment in MPTP-Treated Mice” by Cassandra Peoples, Victoria E. Shaw, Jonathan Stone, Glen Jeffery, Gary E. Baker and John Mitrofanis was published in ISRN Neurology. A copy of it is available here.

The Vision Centre is funded by the Australian Research Council as the ARC Centre of Excellence in Vision Science.

Older brains more capable of learning than previously believed

It is commonly thought that the brain becomes less malleable as we age, leading to the concoction of phrases like "you can't teach an old dog new tricks".

However, researchers claim that in fact the brain is more impressionable in old age than previously thought.

There is evidence to suggest that the brain is capable of learning new information even later in life, but it may need stimulation to activate this plasticity.

New experiences can exert physical changes in the brain over the course of a few days and in some instances may accelerate the physical, chemical and functional remodelling of the organ.

During a roundtable discussion about the latest developments, Dr Michael Merzenich from the University of California San Francisco commented: "All that’s required to drive changes in the brain is exposure to the physical world. With that exposure, the brain competitively sorts information coming in, and refines its responses to it by creating selective, coordinated networks of neurons."

This process continues even into old age, allowing the brain to continue to adapt.

For older adults, these findings highlight the importance of keeping the brain stimulated during the ageing process.

Are tumors fueled by stem cells?

How can a cancer come back after it's apparently been eradicated? Three new studies are bolstering a long-debated idea: that tumors contain their own pool of stem cells that can multiply and keep fueling the cancer, seeding regrowth.
If that's true, scientists will need to find a way to kill those cells, apart from how they attack the rest of the tumor.
Stem cells in healthy tissues are known for their ability to produce any kind of cell. The new research deals with a different kind, cancer stem cells. Some researchers, but not all, believe they lurk as a persisting feature in tumors.
Over the past decade, studies have found evidence for them in tumors like breast and colon cancers. But this research has largely depended on transplanting human cancer cells into mice that don't have immune systems, an artificial environment that raises questions about the relevance of the results.
Now, three studies reported online Wednesday in the journals Nature and Science present evidence for cancer stem cells within the original tumors. Again, the research relies on mice. That and other factors mean the new findings still won't convince everyone that cancer stem cells are key to finding more powerful treatments.
But researcher Luis Parada, of the University of Texas Southwestern Medical Center in Dallas, believes his team is onto something. He says that for the type of brain tumor his team studied, "we've identified the true enemy."
If his finding applies to other cancers, he said, then even if chemotherapy drastically shrinks a tumor but doesn't affect its supply of cancer stem cells, "very little progress has actually been made."
The three studies used labeling techniques to trace the ancestry of cells within mouse tumors.
Collectively, they give "very strong support" to the cancer stem cell theory, said Jeffrey M. Rosen, a professor of molecular and cellular biology at Baylor College of Medicine in Houston. He did not participate in the work but supports the theory, which he said is widely accepted.
Another scientist who's skeptical about the theory, and said he has plenty of company, said the new papers did not change his mind.
Parada's team worked with mice genetically primed to develop a certain type of brain tumor. The scientists genetically labeled particular cells in the tumor and then attacked the cancer with the same drug given to human patients. It kills growing tumor cells and temporarily stops the cancer's growth.
After treatment, when the tumor started growing again in the mice, the researchers showed that the vast majority, if not all, of its new cells had descended from the labeled cells. Apparently these were the tumor's cancer stem cells, they concluded.
Parada said his team is now trying to isolate cancer stem cells from mouse brain cancers to study them and perhaps get some leads for developing therapies to eradicate them.
He also said that preliminary study of human brain tumors is producing results consistent with what his team found in the mice.
Parada's study appears in Nature. In a second Nature report, British and Belgian researchers found evidence for cancer stem cells in early stage skin tumors in mice. And in the journal Science, a Dutch group found such evidence in mouse intestinal polyps, which are precursors to colon cancer.
Scott Kern of the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University in Baltimore is skeptical about whether tumors contain cancer stem cells. He said that since the new studies didn't involve human tumors, it's not clear how relevant they are to people.
The two European studies focused largely on lesions that can lead to tumors, he said. And as for Parada's brain cancer study, he said he believed the results could be explained without relying on the cancer stem cell theory.

Adult human brain remarkably malleable and capable of new feats

There is growing evidence that, beyond what was previously believed, the adult human brain is remarkably malleable and capable of new feats -- even in the last decades of life.
In fact, new experiences can trigger major physical changes in the brain within just a few days, and certain conditions can accelerate this physical, chemical and functional remodeling of the brain.
"We used to think that the brain was completely formed by development and its basic structure didn't change much in adults, but as research went on we discovered that wasn't true, at least in the cerebral cortex," explains Randy Bruno, a member of the Kavli Institute for Brain Science at Columbia University. "We now know that an underlying portion of the brain called the thalamus, which feeds the cortex information from our senses, is also remarkably plastic."
Change can also happen quickly. Using new research techniques on rats, Bruno's lab has found that the neuronal connections bridging the thalamus to the cortex are not only massively plastic, but they grow and retract rather rapidly in only a few days in response to different sensations. "The rapidity of this growth is really striking-it happens within just three days, which is something nobody in the past thought was possible. Those kinds of rapid physical changes also probably occur in other parts of the brain as well."
In fact, certain conditions accelerate this physical, chemical and functional remodeling of the brain. Said Michael Merzenich, Emeritus Professor at the Keck Center for Integrative Neurosciences at the University of California at San Francisco, and Director and founder of the Brain Plasticity Institute, "In our experiments in adult rats, changes only occurred when the animal was attentive within a rewarded learning environment. When we train the animals to improve their behavioral capabilities under near-optimal contextual conditions, we can drive easily recordable functional and physical changes in the cerebral cortex within a day or two. By contrast, little or no change is induced by the passive exposure of an animal to many days of stimulation with thousands of the same stimuli applied in training."
At the same time, there are limitations that come with age. "There is no evidence that there is any part of the adult brain that is not plastic," said Randy Nudo, Director of the Landon Center on Aging and Professor in the Department of Molecular and Integrative Physiology at the University of Kansas. "But studies indicate that some aspects of musical training, such as the ability to perceive temporal patterns, require the brain to be trained during early developmental periods when its primed for certain types of stimuli. For other aspects of musical development, such as the ability to perceive and repeat a sequence of tones, it's irrelevant whether you've had that experience and training early in life."
All of this matters when considering the relationship between age and brain developmental disorders such as autism, Down's syndrome, and dyslexia. "The brain is plastic for life," said Merzenich. "The fundamental thing that determines how much [persons with brain disorders] will improve is the level of their initial impairment, but not their age."

From brain to mouth: The psychology of obesity

Everyone knows that people put on weight because they consume more calories than they burn. But as the medical community struggles to get a handle on obesity in the USA, a growing body of research is delving deeper to find out more about the psychology behind the numbers.
Although people might be inclined to think of nutritionists or dietitians, obesity is "one of the big common public health issues that falls right in the heart of psychology," says psychologist Paul Rozin of the University of Pennsylvania in Philadelphia.
Among a host of questions aimed directly at the psychology of eating are why Americans are eating more than they used to; whether some foods can really be addictive; and whether more people than in the past are genetically predisposed to pack on pounds.
Rozin, who has studied humans and food for 30 years, is one of dozens of psychologists who will share their latest findings and theories this weekend at the American Psychological Association's annual meeting, starting Thursday in Orlando. Obesity is one of the themes.
"Obesity has been much more resistant to treatment than any reasonable person would have thought 50 years ago," he says.
There's no question that Americans are heavier than ever before. More than one-third of adults are considered obese and almost 17% of teens and kids fit the category, according to the most recent federal data, released earlier this year.
In fact, food is everywhere at any time, and advertising is an additional lure, says psychologist Kelly Brownell, director of the Rudd Center for Food Policy & Obesity at Yale University in New Haven, Conn. "We've been completely retrained to think that large portions are acceptable, that eating throughout the day is acceptable, that eating late at night is acceptable, that eating in the car is acceptable," he says. "All the boundaries that would put limits around eating have been exploded."
Among the most-blamed culprits are intense food marketing toward consumers and less physical activity.
But research scientist David Allison has some other ideas. A psychologist who directs the Nutrition Obesity Research Center at the University of Alabama-Birmingham, Allison points to other contributors, such as too little sleep and advanced maternal age, which some research has shown can increase the chances of overweight kids.
Allison's new research, online in Frontiers in Genetics, finds that people with higher body mass index tend to partner with those of similar BMI and may predispose their offspring to obesity. Using Danish height and weight data collected for hundreds of thousands of children at age 13, researchers were able to find 37,792 spousal pairs who married between 1945 and 2010. They then calculated couples' BMIs. The study he co-wrote confirms that those with higher BMIs tended to pair up and suggests the implications for heavier offspring.
"It starts concentrating the genes for BMI within families," he says.
He and others also are looking at cognitive demand. Early findings suggest we may be draining our brains because "we have more cognitively demanding lifestyles."
Significant increases in the prevalence of obesity occurred over the past 30 years, when computers and technology use exploded, Allison says. Being constantly available to others means we are so often occupied with mentally involved tasks that we're on cognitive overload. And that, he says, may be wearing out our self-control to resist food temptations.
Food could be the fuel we need, the reward we want or maybe both, he says. But "if those mental activities lead to increased food intake, that could be a major driver of why we're taking in more food," he says.
"That's not to say any of us want to give up our computers or stop engaging in mentally demanding activities. But we may want to say, 'Are there ways to alter our lifestyle that might protect us?' "
'The buffet effect'
Another area of research focuses on food itself. Studies by Barbara Rolls, director of the Laboratory for the Study of Human Ingestive Behavior at Penn State University in University Park, Pa., have found that something as seemingly innocuous as more variety actually encourages overeating. She says pleasure from eating a food declines while eating. But if other foods at the meal have different tastes, aromas, shapes and textures, instead of stopping eating, people shift to another food that remains appealing.
"It's the buffet effect," she says. "If you go to a place with 50 different kinds of foods, you're going to eat more than if there was just a few."
She co-wrote a study in the August Journal of the Academy of Nutrition and Dietetics in which researchers found that participants ate more vegetables when served three types (broccoli florets, baby carrots or snap peas) at a meal than when served the same amount of just one, even if it was a preferred vegetable. The 66 adults got pasta and cooked vegetables once a week for four weeks; amounts were carefully measured.
Among the more controversial topics to be discussed is food addiction. Some research suggests certain foods "hijack" the brain in ways that resemble addiction to drugs or alcohol.
"Nobody would say food addiction is like morphine, but it does get similar effects," Brownell says. "So the question is, 'Should some of these constituents of food be limited because they're hijacking the brain?' "
Brownell's center is at the forefront of food addiction research. One of its studies, published last year in the Archives of General Psychiatry, gained attention for finding that food cues activated the same brain areas in those who score high on food addiction measures as drugs or alcohol do in those addicted to them. Lead author Ashley Gearhardt, a psychologist, will present research on food addiction in children this weekend.
She also has compiled data on the foods people report stimulate the most addictive response. Generally, she says, they are higher in sugar, fat and salt.
"Ice cream, chocolate and pizza were our three big culprits," says Gearhardt, who this fall moves to the University of Michigan in Ann Arbor as an assistant professor.
"In recent years, science has begun to provide support for food's addictive properties, and food addiction has gained attention as a contributor to obesity," says Rebecca Puhl of the Yale center. "But there has been no research examining how the public perceives food addiction, and whether it is believed to be a legitimate addiction or disease," an area of her latest work.
Still, many are successful at losing weight and keeping it off. Rena Wing, a professor of psychiatry and human behavior at Brown University in Providence, says psychologists have had an influence on the field of obesity.
She has been studying people who have been successful at maintaining long-term weight loss in a national study tracking more than 10,000 people who have lost at least 30 pounds and kept it off at least a year.
Stigma doesn't help
"We have a lot of measures of their behavior," she says, even MRIs showing how people respond to pictures of food. "The pattern of brain responses in successful weight losers suggests they are restraining their responses to the food cues. They exhibit a lot of cognitive control when looking at the pictures — more than normal-weight or overweight people."
But for those who struggle with the pounds, there is continued stigma, says Puhl, director of Research and Weight Stigma Initiatives at the Rudd Center. She says the public may think "maybe a little bit of stigma is not such a bad thing — that maybe it will motivate people to lose weight and provide an incentive for weight loss."
But she says the opposite is true. "When people are stigmatized because of their weight, they are more likely to engage in unhealthy behaviors, like binge eating and unhealthy weight-control practices. They actually increase their food consumption and have lower motivation for physical activity," she says. "They are at increased risk for numerous psychological consequences that includes depression, anxiety, poor body image, low self-esteem and, unfortunately, suicide."
Weight stigma surfaced just last week over Australian Olympic swimmer Leisel Jones when a newspaper in her home country published photos suggesting she had put on weight and polled readers online about whether she was fit enough to swim. Readers were outraged, and the poll was removed within hours.
"We live in a culture that has placed a premium value on thinness," Puhl says.
Rozin's work as a cultural psychologist focuses on how culture frames eating behavior. For a paper comparing French and American eating cultures, published last year in the journal Frontiers in Psychology, he found that Americans emphasize quantity over quality, have a higher preference for variety and prefer convenience in food. He says the French enjoy food more than Americans do — yet are thinner.
"They eat more fat than we do. They don't snack. They have a very strong food culture — which we don't have — as to what a proper meal is. The meal is a real occasion to sit down and relax and spend time together — and not eat too much."

Toddler whose brain was pierced by a pencil makes a full recovery

Toddler's brain pierced by pencil.
Wren Bowell
The father of a toddler who had a pencil pierce her eye socket and lodge in her brain said he was thankful the two-year-old had made a full recovery. Wren Bowell, from Peasedown St John, was getting ready for bed when she fell on to the pencil she was carrying. It narrowly missed her eyeball and lodged in her brain just a millimetre away from a major blood vessel.
Martyn Bowell, Wren's father, said he was "just thankful to have her here still".
Wren was at her home near Bath, last March, when the incident happened.
"She tripped and fell with the pencil and it went through her eye socket," said Mr Bowell.
"It missed her eye fortunately but it went up into her brain and obviously she screamed out and we called an ambulance."
'Pull pencil out' The pencil lodged 1.5in (3.8cm) into the front lobe of the toddler's brain
CT Head scan image showing the pencil The pencil penetrated her right eye socket before lodging 1.5in (3.8cm) into the front lobe of her brain
"I was going to pull the pencil out, which I know now that you're not supposed to because it could have been a lot worse if I had done," said Mr Bowell.
"But thankfully Michelle [Wren's mother] was here and she kept me calm and said 'leave the pencil there and call an ambulance' and we'll wait and we did."
Wren was taken to Frenchay Hospital in Bristol where surgeons operated for four hours to remove it.
Mr Pople, the consultant neurosurgeon who operated on her, said it would have been "impossible" to remove the pencil without surgery.
"It had passed through the skull - fractured the skull - and little bits of fractured bone were holding the pencil inside," he said.
"So even if he'd tried to pull it out, it was just stuck rigid - that was one of the reasons why we had to open up the front of her skull and extricate it.
"But luckily the pencil only just reached the two big arteries right in the middle of the brain and hadn't penetrated them if they had - it would probably have been fatal.
"She was extremely lucky to get away with that without damage."
The incident happened in March and Wren was released from hospital in April.

Child brain study to help understand autism

Child brain study to help understand autism London: Five-month-old Ricky Kimber is taking part in a study that will help researchers understand how babies learn from others and give clues about development of autism.

Infants like Ricky and younger than him will don sensor-filled caps and the researchers at the Durham University will monitor their brain functioning to understand how babies learn from seeing other people do things, the Daily Mailreported .

The university is hoping to bring on board at least 40 other babies, aged up to 10 weeks, for the tests.

The study will be conducted under parental supervision at all times and the babies will `walk` in a small bath.

They will then watch moving computer images of people walking while their brain activity is being monitored which will show the researchers how the babies` brains react to seeing someone walking.

Dr Vincent Reid, lead researcher and a psychologist at the University said he hoped it would help to spot autism in infants at an earlier age.

"While there is no cure for autism, intervention can take place to assist the condition. At present autism is not detected in infants until they are around three years of age," he was quoted by the paper as saying."This research should help us to learn how to possibly detect the condition at an earlier age," he added.

"How babies learn best is important for parents and carers and also gives a better understanding about how the brain reacts to social information, something which is crucial in the early detection of autism," he said.

Scientists wish to underscore that the tests are harmless, painless and non-invasive and none of the infants will be medically tested for autism, the report said.

New microchip helps take detailed images of brain

University of Calgary researchers Orly Yadid-Pecht, left, and Naweed Syed, have achieved a milestone in the further development of a neurochip that can monitor several functions of the brain.

CALGARY — The human brain is an intricate network of tens of billions of cells. But when something goes wrong, it often takes expensive and invasive tools to get a window into what’s happening in the mind.
University of Calgary researchers say they’ve come up with a microchip with a specialized filter that can take diagnostic images of brain cells that are easier for physicians to use, less stressful for patients and cheaper for the health-care system.
“The filters we have built on this microchip are made out of a chewing gum material,” said U of C neuroscientist and head of the cell biology and anatomy department Naweed Syed.
“You can paint it on to the chip and you need not have sophisticated microscopes or cameras and software.”
“The portability of this technique hopefully in future means you could take it into an operating room without having to deal with (MRI’s) where you can’t take all the surgical tools inside,” added Syed who helped test the device.
Findings to be published in this month’s IEEE Photonics Journal show U of C faculty of medicine and engineering researchers have created what they are calling a “lab-on-a-chip” that can take images of individual brain cells.
The biggest challenge was finding a way to ensure brain cells could function well with the microchip and its new filter, said U of C engineer Orly Yadid-Pecht who helped design the new device.
This invention builds on a previous achievement by U of C teams, which invented a neurological microchip that communicates directly with brain cells.
“We’ve been continuously building and exploring means to record brain cell activity, so we could understand brain function better,” Syed said.
The new microchip and its special imaging filter unveiled Wednesday was tested on snail brain cells and will also be studied using rat brain cells.
But it is hoped human brain cells can be adapted to the technology in future.
Ultimately these neurological microchips — known as neurochips — could be used to help screen drugs for disorders such as Parkinson’s disease or epilepsy.
The hope is someday the microchips could also replace dead or damaged brain cells.
“If a brain cell dies, either due to stroke, trauma, injury, Parkinson’s and Alzheimer’s disease there is no current techniques available to regain lost brain function,” Syed said.
“We’re developing these neurochips or brain chips to be able to allow us to hopefully in the future implant these chips inside the brain to regain that lost brain function.”

Child abuse disrupts brain, may cause depression: study

An MRI machine (AFP/Getty Images/File, Matthew Simmons)

PARIS — Children who suffer or witness physical abuse undergo changes to their brain structure that may predispose them to depression and substance abuse later in life, a study said Wednesday.
The finding holds promise for early detection and pre-emptive counselling already in adolescence -- a crucial phase of physical and emotional development and brain maturation, say researchers in the United States.
Using a specialised MRI scanning technique, "we identified microstructural disruption at certain locations of the white matter tracts of adolescents who experienced maltreatment during childhood," researcher Hao Huang told AFP.
White matter tracts or nerve fibres, comparable to computer network cables, connect the grey matter in the brain's different processing regions -- transmitting signals to ensure they "talk" with each other efficiently.
Nineteen adolescents who had suffered physical or sexual abuse before the age of 10 or witnessed domestic violence that lasted six months or longer, took part in the study, as well as a control group of 13 with no abuse history.
Those in the abused group were physically and mentally healthy at the time they were recruited at an average age of 16, and were not abusing alcohol or drugs at the time.
All the teenagers were followed at six-month intervals for up to five years.
"We found that adolescents with maltreatment history who had disrupted white matter tracts during the initial recruitment were more likely to develop depressive and addictive disorders," said Huang of the University of Texas Southwestern Medical Centre's Advanced Imaging Research Centre.
Five of the 19 abuse victims developed depression later, compared to one in the control group, while four became substance abusers compared to one control teenager.
Two from the maltreated group developed both conditions, said the study published in the journal Neuropsychopharmacology.
The adolescents exposed to childhood abuse as well as those who later developed depression had significantly lower FA values -- a measure of white matter efficiency.
"We believe that... brain scans might be helpful in identifying youngsters who are at high risk for developing these disorders and target them for early preventive intervention," said Huang.
Earlier studies had observed similar white matter changes in individuals with a history of abuse, but this was the first to find a link to later psychological problems.
Huang said the exact mechanism by which the white matter tracts were disrupted was not yet understood and required further investigation.

Brain imaging can tell how intelligent you are

Washington, August 2 (ANI): Scientists may have found factors that distinguish the brains of the exceptionally smart persons from those of average individuals.
As science has long suspected, overall brain size matters somewhat, accounting for about 6.7 percent of individual variation in intelligence.
More recent research pinpointed the brain's lateral prefrontal cortex, a region just behind the temple, as a critical hub for high-level mental processing, with activity levels there predicting another 5 percent of variation in individual intelligence.
Now, new research from Washington University in St. Louis has suggested that another 10 percent of individual differences in intelligence can be explained by the strength of neural pathways connecting the left lateral prefrontal cortex to the rest of the brain.
The findings establish "global brain connectivity" as a new approach for understanding human intelligence.
"Our research shows that connectivity with a particular part of the prefrontal cortex can predict how intelligent someone is," said lead author Michael W. Cole, PhD, a postdoctoral research fellow in cognitive neuroscience at Washington University.
The study is the first to provide compelling evidence that neural connections between the lateral prefrontal cortex and the rest of the brain make a unique and powerful contribution to the cognitive processing underlying human intelligence, said Cole, whose research focuses on discovering the cognitive and neural mechanisms that make human behaviour uniquely flexible and intelligent.
One possible explanation of the findings, the research team suggests, is that the lateral prefrontal region is a "flexible hub" that uses its extensive brain-wide connectivity to monitor and influence other brain regions in a goal-directed manner.
"There is evidence that the lateral prefrontal cortex is the brain region that 'remembers' (maintains) the goals and instructions that help you keep doing what is needed when you're working on a task. So it makes sense that having this region communicating effectively with other regions (the 'perceivers' and 'doers' of the brain) would help you to accomplish tasks intelligently," Cole explained.
While other regions of the brain make their own special contribution to cognitive processing, it is the lateral prefrontal cortex that helps coordinate these processes and maintain focus on the task at hand, in much the same way that the conductor of a symphony monitors and tweaks the real-time performance of an orchestra.
"We're suggesting that the lateral prefrontal cortex functions like a feedback control system that is used often in engineering, that it helps implement cognitive control (which supports fluid intelligence), and that it doesn't do this alone," Cole says.
The findings are based on an analysis of functional magnetic resonance brain images captured as study participants rested passively and also when they were engaged in a series of mentally challenging tasks associated with fluid intelligence, such as indicating whether a currently displayed image was the same as one displayed three images ago.
Results indicate that levels of global brain connectivity with a part of the left lateral prefrontal cortex serve as a strong predictor of both fluid intelligence and cognitive control abilities.
Although much remains to be learned about how these neural connections contribute to fluid intelligence, new models of brain function suggested by this research could have important implications for the future understanding - and perhaps augmentation - of human intelligence.
The findings have been published in the Journal of Neuroscience.

Concussions may speed up brain ageing: Study

Concussions may speed up brain ageing: Study
Washington: Concussions and even lesser head impacts may accelerate the brain`s natural ageing process, a new study has claimed.

Researchers from the University of Michigan found that brain injuries can cause signalling pathways in the brain to break down more quickly than they would in someone who has never suffered a concussion.1The study looked at college students with and without a history of concussion and found changes in gait, balance and in the brain`s electrical activity, specifically attention and impulse control.

"The declines were present in the brain injury group up to six years after injury, though the differences between the study groups were very subtle, and outwardly all of the participants looked and acted the same," said Steven Broglio, assistant professor of kinesiology and director of the Neurotrauma Research Laboratory.

The study was published in the journal Exercise and Sport Sciences Reviews.

Researchers asked the participants to perform certain tasks in front of a computer, and took images of their brains.

The brains of the non-concussed group showed a greater area of electrical activation than the participants with a history of brain injury.

The signalling pathways in our brains are analogous to a five-lane highway. On a new highway, traffic runs smoothly and quickly as all lanes are in top shape. However, during normal ageing, the asphalt deteriorates and lanes might become bumpy or even unusable, the study said.

As we age, the brain`s pathways break down and can`t transfer the information as quickly. Concussive and other impacts to the head may result in a `pothole` on the brain`s highway, causing varying degrees of damage and speeding the pathway`s natural deterioration.

"The last thing we want is for people to panic. Just because you`ve had a concussion does not mean your brain will age more quickly or you`ll get Alzheimer`s," Broglio said in a statement.

"We are only proposing how being hit in the head may lead to these other conditions, but we don`t know how it all goes together just yet," Broglio stressed.

Broglio mentioned that other factors, such as lifestyle choices, smoking, alcohol consumption, physical exercise, family history and whether or not you exercise your brain also impact the brain`s ageing process; concussion may only be one small factor.

Stem cell findings point toward new cancer treatments

Scientists hope that if drugs are designed to kill or disable "cancer stem cells" like this one, they could eradicate the tumor. (UCLA / August 1, 2012)

Cancer stem cellWhen cancers are treated, tumors may shrink but then come roaring back. Now studies on three different types of tumors suggest a key reason why: The cancers are fueled by stem cells that chemotherapy drugs don't kill.
The findings — made by independent research teams that used mice to study tumors of the brain, intestines and skin — could change the approach to fighting cancers in humans, experts said.
Properties of these so-called cancer stem cells can be investigated so researchers can devise strategies for killing them off, said Luis F. Parada, a molecular geneticist at the University of Texas Southwestern Medical Center in Dallas and senior author of one of the studies published Wednesday.
"Everything has a soft underbelly once you understand it well," Parada said. "With all the modern molecular techniques and modern approaches we have, we should be able to find their soft underbelly."
Cancer researchers have long suspected — and some pioneering studies have strongly suggested — that specific cells within tumors are responsible for their continued growth. But the earlier experiments hadn't convinced everyone, and the hypothesis has been controversial.
The three papers published by the journals Nature and Science "really should seal the deal," said cancer biologist Owen Witte, director of the Broad Stem Cell Research Center at UCLA.
"People can stop arguing," he said. "Now they can say, 'OK, the cells are here. We now need to know how to treat them.' "
All three studies used molecular tricks that allowed scientists to mark certain tumor cells with bright colors. When these marked cells divided, all of the daughter cells were similarly colored. This permitted the researchers to see whether any old cell in a tumor can continue to fuel its growth or if only a subset of cells is responsible.
The three groups used different experimental approaches and different kinds of cancer, but all of them found the latter to be true.
Parada's group, whose work was published in Nature, studied an aggressive cancer called glioblastoma that arises when brain cells called glia turn rogue. The scientists started with a hunch — if a cancer stem cell existed, it would have biological similarities to the stem cells that normally exist in the brain.
To test whether this was true, the team created glioblastoma-prone mice whose brain stem cells glowed green. When those cells divided, their daughter cells contained some of the green dye too. After enough generations, the dye was diluted away.
Sure enough, the mice developed brain tumors. When the researchers examined those tumors, they found a small number of green-glowing cells that weren't actively dividing, unlike the rest of the tumor.
It looked as though the scientists had detected cancer stem cells.
Next, the scientists treated the mice with a chemotherapy drug that kills rapidly dividing tumor cells. When the tumors grew back, as glioblastomas generally do, the scientists used other chemical tricks to see that the new cells were all descendants of the green-glowing cells that weren't killed by the drug.
The next step was to see what would happen if the cancer stem cells were wiped out, a test that was possible because of the way the mice were genetically constructed. Without the stem cells, the tumors never grew as large and the animals lived longer.
The scientists concluded that they had destroyed the wellspring of cells that renew the tumor when other cancer cells within the mass stop dividing.
In the two other papers, cancer cells with stem-cell-like properties were found in mouse intestinal adenomas, which give rise to intestinal cancers, by Dr. Hans Clevers at the Hubrecht Institute in the Netherlands; and in squamous cell skin tumors by Dr. Cedric Blanpain at the Free University of Brussels. Those papers were published in Science and Nature, respectively.
There are still many unknowns, said MIT cancer researcher Robert Weinberg, who wasn't involved in the studies. Among them: Do these cells come from a tissue's normal stem cells or somewhere else? What makes them turn rogue? Do most — or even all — cancers work this way?
Even so, the implications are obvious, he and others said: Doctors can't just go after the rapidly dividing cells if they want to effectively fight a cancer.
"Unless we treat the cell of origin, we won't cure the patient," said Dr. Jenny Chang, director of the Cancer Center at Methodist Hospital in Houston.
Today, cancer medications generally kill only rapidly dividing cells, and scientists don't yet know enough about cancer stem cells to target them. Biotech companies and academics are working on the problem.
Overall, scientists are finding that cancers are grotesque caricatures of normal body tissues, said John E. Dick, senior scientist at Toronto's Princess Margaret Cancer Center, whose work in the 1990s provided early evidence for stem cells in leukemia.
Just as healthy tissues contain a mix of cells — ones that are dividing, ones that have taken on distinct identities, and stem cells that periodically replenish the tissue — so, too, do cancers.
And just as normal tissue growth involves a complicated dance of chemical messages among cells, so, too, might the growth of cancers.
That complexity makes the prospect of devising new therapies seem daunting, Dick said. But, he added, it opens up a whole new menu of strategies that scientists can try.