Posts tagged psychology

ScienceDaily (Apr. 2, 2012) — Why do some persons succumb to post-traumatic stress disorder (PTSD) while others who suffered the same ordeal do not? A new UCLA study sheds light on the answer.

UCLA scientists have linked two genes involved in serotonin production to a higher risk of developing PTSD. Published in the April 3 online edition of the Journal of Affective Disorders, the findings suggest that susceptibility to PTSD is inherited, pointing to new ways of screening for and treating the disorder.

"People can develop post-traumatic stress disorder after surviving a life-threatening ordeal like war, rape or a natural disaster," explained lead author Dr. Armen Goenjian, a research professor of psychiatry at the Semel Institute for Neuroscience and Human Behavior at UCLA. "If confirmed, our findings could eventually lead to new ways to screen people at risk for PTSD and target specific medicines for preventing and treating the disorder."

PTSD can arise following child abuse, terrorist attacks, sexual or physical assault, major accidents, natural disasters or exposure to war or combat. Symptoms include flashbacks, feeling emotionally numb or hyper-alert to danger, and avoiding situations that remind one of the original trauma.

Goenjian and his colleagues extracted the DNA of 200 adults from several generations of 12 extended families who suffered PTSD symptoms after surviving the devastating 1988 earthquake in Armenia.

In studying the families’ genes, the researchers found that persons who possessed specific variants of two genes were more likely to develop PTSD symptoms. Called TPH1 and TPH2, these genes control the production of serotonin, a brain chemical that regulates mood, sleep and alertness — all of which are disrupted in PTSD.

"We suspect that the gene variants produce less serotonin, predisposing these family members to PTSD after exposure to violence or disaster," said Goenjian. "Our next step will be to try and replicate the findings in a larger, more heterogeneous population."

Affecting about 7 percent of Americans, PTSD has become a pressing health issue for a large percentage of war veterans returning from Iraq and Afghanistan. The UCLA team’s discovery could be used to help screen persons who may be at risk for developing PTSD.

"A diagnostic tool based upon TPH1 and TPH2 could enable military leaders to identify soldiers who are at higher risk of developing PTSD, and reassign their combat duties accordingly," observed Goenjian. "Our findings may also help scientists uncover alternative treatments for the disorder, such as gene therapy or new drugs that regulate the chemicals responsible for PTSD symptoms."

According to Goenjian, pinpointing genes connected with PTSD symptoms will help neuroscientists classify the disorder based on brain biology instead of clinical observation. Psychiatrists currently rely on a trial and error approach to identify the best medication for controlling an individual patient’s symptoms.

Serotonin is the target of the popular antidepressants known as SSRIs, or selective serotonin re-uptake inhibitors, which prolong the effect of serotonin in the brain by slowing its absorption by brain cells. More physicians are prescribing SSRIs to treat psychiatric disease beyond depression, including PTSD and obsessive compulsive disorder.

Source: Science Daily

March 30th, 2012

A new animal model of nerve injury has brought to light a critical role of an enzyme called Nmnat in nerve fiber maintenance and neuroprotection. Understanding biological pathways involved in maintaining healthy nerves and clearing away damaged ones may offer scientists targets for drugs to mitigate neurodegenerative diseases such as Huntington’s and Parkinson’s, as well as aid in situations of acute nerve damage, such as spinal cord injury.

University of Pennsylvanian biologists developed the model in the adult fruit fly, Drosophila melanogaster.

“We are using the basic power of the fly to learn about how neurons are damaged in acute injury situations,” said Nancy Bonini, senior author of the research and a professor in the Department of Biology at Penn. “Our work indicates that Nmnat may be key.”

The research was published in Current Biology. First author on the study is postdoctoral researcher Yanshan Fang, with additional contributions from postdoctoral researcher Lorena Soares and research technicians Xiuyin Teng and Melissa Geary, all of Penn’s Department of Biology.

When a nerve suffers an acute injury — as might be caused by a penetrating wound, for example, or a broken bone that damages nearby tissues — the long projection of the nerve cell, called the axon, can become injured and degenerate. The process by which it disintegrates is known as Wallerian or Wallerian-like degeneration and is an active, orderly process.

Though this function of eliminating damaged nerve cells is crucial, biologists do not have a clear understanding of all of the molecular signaling pathways that govern the process.

Bonini’s lab has previously focused on chronic neurodegenerative diseases but made this foray into acute nerve injury to determine if mechanistic overlaps exist between acute axon injury and chronic neurodegeneration. They first searched for an appropriate nerve tract to target and identified the wing of adult flies as a prime option.

The fly wing is not only translucent and a site of lengthy nerve fibers that can be easily observed, but it can also be cut to cause injury without killing the fly. That way, the researchers can follow the animal’s response to nerve injury for weeks.

Using various reagents to manipulate the fly’s genetic traits, the team confirmed that the cut wing nerve underwent Wallerian degeneration. They then tested versions of Nmnat and another protein called Wld^S, all of which had previously been shown to protect nerves from degeneration, to see if any of these might stop the process. All significantly delayed neurodegeneration. Even a form of Nmnat that hadn’t worked in other animal models suppressed degeneration, although to a lesser extent.

“That indicates that our assay is really sensitive,” Bonini said. “This sensitivity could help us identify genes that have moderate although important functionality at protecting against nerve degeneration.”

Their investigations into the wing nerve also showed that the degenerating axon “died back,” fragmenting first from the axon terminals, the side farthest from the nerve cell body—a pattern similar to what has been seen in other disorders.

Doing more genetic tinkering, the researchers showed that when the animal’s own Nmnat was depleted, the nerves fragmented in the same way as if the axon was physically cut. And when Nmnat and the other “rescue” proteins were added back to these genetically modified flies, they were able to block degeneration, highlighting that Nmnat is critical to maintaining healthy axons.

In a final set of experiments, the biologists sought to narrow where in the nerve cells Nmnat might be working. They focused on mitochondria, the powerhouses of cells. When they created a genetic line of flies that blocked mitochondria from entering the axon fibers, the nerve tract degenerated, again, in a dying-back fashion. Yet now Wld^S and Nmnat failed to prevent axon degeneration, suggesting that those proteins may act on and require the presence of axonal mitochondria to maintain healthy nerves in normal flies.

Flipping that scenario around, they looked to see what happened to the mitochondria of flies upon nerve injury. When they cut the wing nerve axons, the mitochondria rapidly disappeared. Yet they can largely preserve the mitochrondria by increasing expression of Nmnat.

Their results, taken together with the findings of other studies, suggest that Nmnat may stabilize mitochondria in some way in order to keep axons in a healthy state.

“We have some hope that these proteins or their activity may someday serve as drug targets or could provide the foundation for a therapeutic advance,” Bonini said. “But right now, my hope is that the power of the fly model will open up a lot of new directions of research and new pathways that could be targets for development in the future.”

Source: Neuroscience News

16:55 30 March 2012

Sumit Paul-Choudhury, editor

My Soul, 2005, Katharine Dowson (Image: Image courtesy of the artist and GV Art)

LOOKING at your own brain is a humbling and slightly unnerving experience. Mine, depicted in a freshly acquired MRI scan, is startlingly intricate, compact - and baffling. This is as much of a portrait of my own mind as I am ever likely to see. But to my ignorant eyes (which, by way of an eerie bonus, are now looking at their own cross-sections) it looks pretty much like any other brain.

Apparently a more expert eye wouldn’t help. “Whilst all my participants get very excited about seeing their brain for the first time after being scanned, and I frequently get asked ‘What can you tell me about my brain?’, the reality is that the brain will for a long time yet remain a mysterious mass,” says the neuroscientist who scanned my brain, for research purposes. “We must be content with knowing that the ‘I’ is constructed in its intricacies, but we cannot explain how.”

The hope of closing the gap between the physical and mental is presumably what gets neuroscientists up in the morning, but it’s frustrating for a layperson like me. Avowed materialist though I am, I nonetheless rebel against the knowledge that the impassive blob on screen is “me”.

This cognitive dissonance was what I took with me to the opening of Brains, a new show at London’s Wellcome Collection, whose subtitle, “The Mind as Matter”, suggests that its curators sympathise with my materialist perspective. “The neurosciences hold out the prospect of an objective account of consciousness - the soul or mind as nothing more than intricately connected flesh,” reads the introduction. But the bulk of the exhibition is dedicated to whole brains, brain collectors and anatomical paraphernalia, with little explicit reference to the brain’s fine structure, or how it might give rise to thought.

This remit is less restrictive than it might sound. Evolution has seen to it that the most vital of our bodily organs is well guarded against intrusion, and as a by-product, well hidden from inspection. Even today, only a small minority of the population have seen their own brains - and many (unlike me, thankfully) have done so only when they had reason to be fearful of what they found.

So the history of attempts to access, visualise and understand the brain is a rich one. But it’s also well worn, and some of the historical material - elaborate anatomical models, kooky phrenological busts and grim-looking surgical implements - is over-familiar. The scientific objects are more compelling, albeit they also tend to the grotesque - from the arachnid contraptions used to measure skull size to the spools of finely-sliced mouse-brains on tape.

Much of the fascination lies not in the objects themselves, but in the human stories behind them, told in captions whose straight-facedness sometimes comes across as drollery or clinical detachment. Trepanning tools fashioned from flint and animal teeth “would have taken longer to cut through the skull than more modern instruments”, one informs us drily; the American Anthropometric Society was “basically a club to enable the leading men of US science to dissect each other,” says another.

Secluded in the skull, individual brains develop relatively few distinguishing features save those given them by trauma, disease or rare accidents of birth. So brains of note tend to be associated with tales of misfortune. That’s often the case with anatomical specimens, but what’s remarkable about the brains on display here is how much they overlap with criminality. Some of the most striking have been acquired from people whose wickedness in life was deemed sufficient reason to deny them dignity in death. In other cases, the moral equation is reversed, with collectors stepping outside the bounds of decency in their desire to possess the brain; the abhorrent nadir being reached with the probable murder of “feeble” children by Nazi doctors.

(Image: Science Museum, London)

The collection’s examples of brains being voluntarily donated are equally remarkable. Persuading someone to donate this most personal of organs is a tough sell, and the historical portion of the exhibition makes much of how appeals to ego have persuaded the great and good to offer up their brains for post-mortem examination. More recently, medical study has provided motivation for would-be donors. Particularly poignant is the tale of Anita Newcomb McGee, a female US army surgeon who gave up her nine-month old son’s brain, along with a photograph and a sketch of his head, with the words “I want him to benefit the world in some way if possible.”

But this altruism is tempered by the fact that brains, unlike many of our other “charismatic organs”, cannot conceivably be transplanted. The knowledge that someone else might gain life from my gifted heart is a powerful incentive to donate, but I have less incentive to be generous with my brain - though it would seem that distinction is not made by those who do donate. Perhaps reluctant donors might be won over by the moving photos compiled by artist Ania Dabrowska and social scientist Bronwyn Parry of cheerful would-be donors ranging from an ex-soldier to a headmistress.

And one of the exhibition’s stand-out exhibits might provide further reassurance: a documentary video of anatomists at London’s Hammersmith Hospital painstakingly and precisely slicing donated brains into half-centimetre wedges in near-silence. Or perhaps not. This is well sanctioned, respectful science being conducted on freely donated organs for the betterment of human health and knowledge; and yet it nonetheless provokes one of my fellow spectators into muttering, very much to herself: “Wrong, wrong, wrong”. For myself, I find the video one of the most compelling exhibits — perhaps the only one that prompts me to contemplate offering myself up for more than a non-invasive scan in the service of medical science.

Less clear-cut, for me, are the nearby sections of Einstein’s brain, preserved under deeply dubious circumstances after his death. Clearly, there’s a certain fascination associated with perhaps the most famous brain there ever was; but Einstein’s brain is no more legible than any other, and the slim prospect that scientific insights can be gleaned from its study seems poor recompense for the undignified proxying of a great mind by illicitly-obtained fragments of tissue.

(Image: Wellcome Library, London. Wellcome Images)

The final insult: an accompanying 3D-printed replica of the entire organ, reconstructed for a TV documentary from archive photographs. This absurd resin relic epitomises, for me, the extent to which the objects on display at the Wellcome are imbued with significance by the knowledge that they were once the seats of consciousness. It’s the minds of the audience, rather than the brains on display, that are doing the work.

The Wellcome show confronts its visitors with the gulf between our hard-won knowledge about the form of the brain and our as-yet-meagre understanding of its function, much as my scan did to me. It didn’t narrow the gap between the grey image of my brain and my sense of self; if anything, it widened it. But it did make me appreciate what an amazing gap it is, and marvel anew at the work of those who are seeking to close it.

Brains: The mind as matter is showing at the Wellcome Collection in London until 17 June.

Source: New Scientist

March 30, 2012

A team of neuroscientists from the Institute of Psychiatry (IoP) at King’s College London have developed a digital atlas of the human brain for iPad. The ‘Brain’ App is the first of its kind, and is based on cutting edge neuro-imaging research from the NatBrainLab at the IoP. 

Image taken from the ‘Brain’ Study Room

Dr. Marco Catani, Head of the NatBrainLab who led the development of the App with Dr. Flavio Dell’Acqua and Dr. Michel Thiebaut de Schotten, said: “For 10 years our lab has pioneered the use of highly advanced neuro-imaging techniques. This is the first time that imaging methods usually only applied to research have been used in an educational App. It’s very exciting to see our work transformed into such an accessible, fun and beautiful tool.”

Image taken from the ‘Brain’ Dissection Room

Two types of scans were used to develop the content of ‘Brain’ – results from an MRI scan reveal the structural properties of the brain, and images from a Diffusion Tractography scan allow the user to identify connections in the brain. 

The App is split into two virtual rooms. The Dissection Room allows the user to play with a 3D human brain, select individual structures and ‘pull’ them apart to visualize their anatomical features. The Study Room then offers a more thorough explanation of functional aspects and their relationship to neurological and psychiatric disorders. 

Dr. Catani adds: “The interactive nature of our App really allows you to explore the depths of the neural network and appreciate the complexity of the human brain. Because the content is based directly on research, the finished product is an accurate reflection of the real thing.”

Dr. Catani and his team are now working towards developing the next version of the App. By integrating scans from several different brains into the programme, they hope to be able to offer the user the chance to see directly how the brain develops from childhood to old age and the direct effect of different age-related disorders on the brain.

The App is currently being used by Dr. Catani and his colleagues to teach MSc students neuroscience.

Provided by King’s College London

Source: medicalxpress.com

March 30, 2012

An estimated 2.2 million people in the United States live with epilepsy, a complex brain disorder characterized by sudden and often unpredictable seizures. The highest rate of onset occurs in children and older adults, and it affects people of all ethnicities and socio-economic backgrounds, yet this common disorder is widely misunderstood. Epilepsy refers to a spectrum of disorders with seizures that vary in type, cause, severity, and frequency. Many people do not know the causes of epilepsy or what measures to take if they witness a seizure. A new report from the Institute of Medicine highlights numerous gaps in the knowledge and management of epilepsy and recommends actions for improving the lives of those with epilepsy and their families and promoting better understanding of the disorder.

Effective treatments for epilepsy are available but access to treatment and timely referrals to specialized care are often lacking, the report’s expert committee found. Reaching rural and underserved populations, as well as providing state-of-the art care for people with persistent seizures, is particularly crucial. The report’s recommendations for expanding access to patient-centered health care include early identification and treatment of epilepsy and associated health conditions, implementing measures that assess quality of care, and establishing accreditation criteria and processes for specialized epilepsy centers. In addition, the wide variety of health professionals who care for those with epilepsy need improved knowledge and skills to provide the highest quality health care.

Some causes of epilepsy, such as traumatic brain injury, infection, and stroke, are preventable. Prevention efforts should continue for these established risk factors, as well as for recurring seizures in people with epilepsy and depression, and for epilepsy-related causes of death, the report says.

People with epilepsy need additional education and skills to optimally manage their disorder. Consistent delivery of accurate, clearly communicated health information from sources that include health care professionals and epilepsy organizations can better prepare those with epilepsy and their families to cope with the disorder and its consequences, the report says. Accurate, current data on the extent and consequences of epilepsy and its associated health conditions are especially needed to inform policymakers and identify opportunities for reducing the burden of epilepsy.

Living with epilepsy can affect employment, driving ability, and many other aspects of quality of life. The report stresses the importance of improved access to a range of community services, including vocational, educational, transportation, transitional care, and independent living assistance as well as support groups. The committee urged collaboration among federal agencies, state health departments, and relevant epilepsy organizations to improve and integrate these services and programs, particularly at state and local levels.

Misperceptions about epilepsy persist and a focus on raising public awareness and knowledge is needed, the report adds. Educating community members such as teachers, employers, and others on how to manage seizures could help improve public understanding of epilepsy. The report suggests several strategies for stakeholders to improve public knowledge of the disorder, including forming partnerships with the media, establishing advisory councils, and engaging people with epilepsy and their families to serve as advocates and educators within their communities.

Provided by National Academy of Sciences

Source: medicalxpress.com

ScienceDaily (Mar. 30, 2012) — Human attention to a particular portion of an image alters the way the brain processes visual cortex responses to that image.

A schematic diagram of the contrast discrimination task, showing the focal cue trial (top row) and the distributed cue trial (bottom row). The contrast within the top right circle increases from the first interval (second column) to the second interval (fourth column). The third column is the interstimulus interval. (Credit: Copyright 2011 Elsevier Inc.)

Our ability to ignore some, but not other stimuli, allows us to focus our attention and improve our performance on a specific task. The ability to respond to visual stimuli during a visual task hinges on altered brain processing of responses within the visual cortex at the back of the brain, where visual information is first received from the eyes. How this occurs was recently demonstrated by an international team of researchers led by Justin Gardner at the RIKEN Brain Science Institute in Wako.

In a contrast discrimination task, the researchers showed three observers a stimulus of a group of four circles, each containing grey and white bars that created stripes of different contrasts. After a short pause, the researchers showed the circles again, but the contrast within one of the circles was different. The observers were instructed to choose which group of circles contained the higher contrast.

In ‘focal cue trials’, an arrow directed the observers’ attention to a particular circle. In ‘distributed cue’ trials’, four arrows directed their attention diffusely, across all four circles. Gardner and colleagues found that the observers’ performance was better in the focal cue trials.

Using a magnetic resonance imaging (MRI) scanner, the research team was able to map the precise location within the visual cortex that was activated by the visual information within each of the four circles. During the contrast discrimination task, Gardner and colleagues could therefore measure the observers’ visual cortex activity elicited by the stimuli. In this way, they could correlate brain activity in the visual cortex with the observers’ attention and their choice of contrasting circles.

Visual cortex responses tended to be largest when the observers were paying attention to a particular target circle, and smallest when they were ignoring a circle. The researchers determined that the largest visual cortex responses to the stimuli guided the eventual choice of each observer, leading to enhanced performance on the visual task.

"We used computational modeling to test various hypotheses about how attention affects brain processing of visual information to improve behavioral performance," explains Gardner. "We concluded that the observers’ attention causes their brains to select the largest cortical response to guide contrast choice, since we found that an ‘efficient selection’ model best explained the behavioral and fMRI data," he says.

If the findings extend to other senses, such as hearing, researchers may begin to understand how humans make sense of a perceptually cluttered world.

Source: Science Daily

ScienceDaily (Mar. 29, 2012) — A type of cell plentiful in the brain, long considered mainly the stuff that holds the brain together and oft-overlooked by scientists more interested in flashier cells known as neurons, wields more power in the brain than has been realized, according to new research published March 29 in Science Signaling.

Human astrocytes. (Credit: Image courtesy of University of Rochester Medical Center)

Neuroscientists at the University of Rochester Medical Center report that astrocytes are crucial for creating the proper environment for our brains to work. The team found that the cells play a key role in reducing or stopping the electrical signals that are considered brain activity, playing an active role in determining when cells called neurons fire and when they don’t.

That is a big step forward from what scientists have long considered the role of astrocytes — to nurture neurons and keep them healthy.

"Astrocytes have long been called housekeeping cells — tending to neurons, nurturing them, and cleaning up after them," said Maiken Nedergaard, M.D., D.M.Sc., professor of Neurosurgery and leader of the study. "It turns out that they can influence the actions of neurons in ways that have not been realized."

Proper brain function relies on billions of electrical signals — tiny molecular explosions, really — happening remarkably in sync. Recalling the face of a loved one, swinging a baseball bat, walking down the street — all those actions rely on electrical signals passed instantly along our nerves like a molecular hot potato from one brain cell to another.

For that to happen, the molecular brew of chemicals like sodium, calcium and potassium that brain cells reside in must be just right — and astrocytes help to maintain that balanced environment. For instance, when a neuron sends an impulse, or fires, levels of potassium surrounding the cell jump dramatically, and those levels must come down immediately for the brain to work properly. Scientists have long known that that’s a job for astrocytes — sopping up excess potassium, ending the nerve pulse, and restoring the cells so they can fire again immediately.

In the paper in Science Signaling, Nedergaard’s team discovered an expanded role for astrocytes. The team learned that in addition to simply absorbing excess potassium, astrocytes themselves can cause potassium levels around the neuron to drop, putting neuronal signaling to a stop.

"Far from only playing a passive role, astrocytes can initiate the uptake of potassium in a way that affects neuronal activity," said Nedergaard. "It’s a simple, yet powerful mechanism for astrocytes to rapidly modulate neuronal activity."

Nedergaard has investigated the secret lives of astrocytes for more than two decades. She has shown how the cells communicate using calcium to signal. Nearly 20 years ago in a paper in Science, she pioneered the idea that glial cells like astrocytes communicate with neurons and affect them. Since then, has been a lot of speculation by other scientists that chemicals call gliotransmitters, such as glutamate and ATP, are key to this process.

In contrast, in the latest research Nedergaard’s team found that another signaling system involving potassium is at work. By sucking up potassium, astrocytes quell the firing of neurons, increasing what scientists call “synaptic fidelity.” Important brain signals are crisper and clearer because there is less unwanted activity or “chatter” among neurons that should not be firing. Such errant neuronal activity is linked to a plethora of disorders, including epilepsy, schizophrenia, and attention-deficit disorder.

"This gives us a new target for a disease like epilepsy, where signaling among brain cells is not as controlled as it should be," said Nedergaard, whose team is based in the Division of Glia Disease and Therapeutics of the Center for Translational Neuromedicine. of the Department of Neurosurgery

The first authors of the paper are Fushun Wang, Ph.D., research assistant professor of Neurosurgery; and graduate student Nathan Anthony Smith. They did much of the work by using a sophisticated laser-based system to monitor the activity of astrocytes in the living brain of rats and mice. The work by Smith, a graduate student in the University’s neuroscience program, was supported by a Kirschstein National Research Service Award from the National Institute of Neurological Disorders and Stroke (NINDS).

Other authors from Rochester include Takumi Fujita, Ph.D., post-doctoral associate; Takahiro Takano, Ph.D., assistant professor; Qiwu Xu, technical associate; and Lane Bekar, Ph.D., formerly research assistant professor, now at the University of Saskatchewan. Also contributing were Akemichi Baba of Hyogo University of Health Sciences in Japan, and Toshio Matsuda of Osaka University in Japan.

Nedergaard notes that the complexity and size of our astrocytes is one of few characteristics that differentiate our brains from rodents. Our astrocytes are bigger, faster, and much more complex in both structure and function. She has found that astrocytes contribute to conditions like stroke, Alzheimer’s, epilepsy, and spinal cord injury.

"Astrocytes are integral to the most sophisticated brain processes," she added.

Source: Science Daily

ScienceDaily (Mar. 29, 2012) — Certain genes and proteins that promote growth and development of embryos also play a surprising role in sending chemical signals that help adults learn, remember, forget and perhaps become addicted, University of Utah biologists have discovered.

This is a microscope image of the roundworm or nematode C. elegans with its nervous system glowing green due to labeling with a green jellyfish protein. (Credit: Penelope Brockie, University of Utah.)

"We found that these molecules and signaling pathways [named Wnt] do not retire after development of the organism, but have a new and surprising role in the adult. They are called back to action to change the properties of the nervous system in response to experience," says biology Professor Andres Villu Maricq, senior author of the new study in the March 30 issue of the journal Cell.

The study was performed in C. elegans — the millimeter-long roundworm or nematode — which has a nervous system that serves as a model for those of vertebrate animals, including humans.

Because other Wnt pathways in worms are known to work in humans too, the researchers believe that Wnt genes, the Wnt proteins they produce and so-called “Wnt signaling” also are involved in human learning, memory and forgetting.

"Almost certainly what we have discovered is going on in our brain as well," Maricq says. And because a worm nerve-signal "receptor" in the study is analogous to a human nicotine receptor involved in addiction, schizophrenia and some other mental disorders, some of the genes identified in the worm study "represent possible new targets for treatment of schizophrenia and perhaps addiction," he adds.

Wnt genes and their proteins already were known to “pattern the development and distribution of organs in the body” during embryo development, and to be responsible for various cancers and developmental defects when mutated, he says.

Maricq conducted the study with these Utah biologists: doctoral students Michael Jensen and Dane Maxfield; postdoctoral researchers Michael M. Francis, Frederic Hoerndli and Rui Wang; undergraduate Erica Johnson; Penelope Brockie, a research associate professor; and David M. Madsen, a senior research specialist.

Read more …

March 29, 2012

(Medical Xpress) — Brain stimulation can markedly improve people’s ability to solve highly complex problems, a recent University of Sydney study suggests.

(L-R) Professor Allan Snyder and Richard Chi found brain stimulation helped people solve a puzzle.

The findings by Professor Allan Snyder and Richard Chi, from the University of Sydney, are published in Neuroscience Letters.

"The results suggest non-invasive brain stimulation could assist people in solving tasks that appear straightforward but are inherently difficult," said Professor Snyder.

Our minds have evolved to solve certain problems effortlessly, yet we struggle to solve others that appear simple but require us to apply an unfamiliar paradigm, to ‘think outside the box’.

The famous ‘nine dots puzzle’. Can you join them using only four straight lines without taking your pen off the page?

"As an example we have taken the famous nine dots problem, where you are asked to join all the dots with four straight lines without taking the pen off the page," Professor Snyder said.

"Surprisingly, investigations over the last century show that almost no one can do this."

Now the researchers have shown that more than 40 percent of the people they tested were able to solve the nine dots problem after receiving 10 minutes of safe, non-invasive brain stimulation.

Specifically the left anterior temporal lobe of the brain is inhibited while simultaneously the right anterior temporal lobe is excited, employing a technique known as transcranial direct current stimulation.

Using the same procedure the researchers have previously reported success in amplifying insight and memory.

Chi and Snyder suggest that their unique brain stimulation protocol could ultimately enable people to “escape the tricks our minds impose on us,” as Professor Snyder describes it, and solve tasks that appear deceptively simple.

Provided by University of Sydney

Source: medicalxpress.com

March 29, 2012

The first atlas of the surface of the human brain based upon genetic information has been produced by a national team of scientists, led by researchers at the University of California, San Diego School of Medicine and the VA San Diego Healthcare System. The work is published in the March 30 issue of the journal Science.

This is a genetic clustering map of the brain, left lateral view. Credit: UC San Diego School of Medicine

The atlas reveals that the cerebral cortex – the sheet of neural tissue enveloping the brain – is roughly divided into genetic divisions that differ from other brain maps based on physiology or function. The genetic atlas provides scientists with a new tool for studying and explaining how the brain works, particularly the involvement of genes.

"Genetics are important to understanding all kinds of biological phenomena," said William S. Kremen, PhD, professor of psychiatry at the UC San Diego School of Medicine and co-senior author with Anders M. Dale, PhD, professor of radiology, neurosciences, and psychiatry, also at the UC San Diego School of Medicine.

According to Chi-Hua Chen, PhD, first author and a postdoctoral fellow in the UC San Diego Department of Psychiatry, “If we can understand the genetic underpinnings of the brain, we can get a better idea of how it develops and works, information we can then use to ultimately improve treatments for diseases and disorders.”

The human cerebral cortex, characterized by distinctive twisting folds and fissures called sulci, is just 0.08 to 0.16 inches thick, but contains multiple layers of interconnected neurons with key roles in memory, attention, language, cognition and consciousness.

Other atlases have mapped the brain by cytoarchitecture – differences in tissues or function. The new map is based entirely upon genetic information derived from magnetic resonance imaging (MRI) of 406 adult twins participating in the Vietnam Era Twin Registry (VETSA), an ongoing longitudinal study of cognitive aging supported in part by grants from the National Institutes of Health (NIH). It follows a related study published last year by Kremen, Dale and colleagues that affirmed the human cortical regionalization is similar to and consistent with patterns found in other mammals, evidence of a common conservation mechanism in evolution.

"We are excited by the development of this new atlas, which we hope will help us understand aging-related changes in brain structure and cognitive function now occurring in the VETSA participants," said Jonathan W. King, PhD, of the National Institute on Aging, part of the NIH.

The atlas plots genetic correlations between different points on the cortical surface of the twins’ brains. The correlations represent shared genetic influences and reveal that genetic brain divisions do not map one-to-one with traditional brain divisions that are based on structure and function. “Yet, the pattern of this genetic map still suggests that it is neuroanatomically meaningful,” said Kremen.

Kremen said the genetic brain atlas may be especially useful for scientists who employ genome-wide association studies, a relatively new tool that looks for common genetic variants in people that may be associated with a particular trait, condition or disease.

Provided by University of California - San Diego

Source: medicalxpress.com