Posts tagged brain
Articles and news from the latest research reports.
Scientists to simulate human brain inside a supercomputer
Scientists at its forerunner, the Switzerland-based Blue Brain Project, have been working since 2005 to feed a computer with vast quantities of data and algorithms produced from studying tiny slivers of rodent gray matter.
Last month they announced a significant advancement when they were able to use their simulator to accurately predict the location of synapses in the neocortex, effectively mapping out the complex electrical brain circuitry through which thoughts travel.
Henry Markram, the South African-born neuroscientist who heads the project, said the breakthrough would have taken “decades, if not centuries” to chart using a real neocortex. He said it was proof their concept, dubbed “brain in a box” by Nature magazine, would work.
Now the team are joining forces with other scientists to create the Human Brain Project. As its name suggests, they aim to scale up their model to recreate an entire human brain.
It is a step that will need both a huge increase in funding and access to computers so advanced that they have yet to be built.
If their current bid for €1 billion ($1.3 billion) of European Commission funding over the next 10 years is successful, Markram predicts that his computer neuroscientists are a decade away from producing a synthetic mind that could, in theory, talk and interact in the same way humans do.
Doctors took an hour to realise Sarah Merriman had Down’s syndrome after her birth in January 1992. By then, her father, Andy, had phoned friends and family to tell them his wife, Alison, had given birth to a healthy baby. His happy news was dashed. “It was a real shock,” Andy recalls. “From the start, we were warned about the difficulties and troubles that lay ahead for Sarah. Then she was diagnosed as having a hole in her heart. The worry, for the first years of her life, was constant.”
Sarah’s heart healed. She did well at her school in Haringey, north London, and went on to pass the equivalent of four GCSEs. Today, she is studying catering and lives with other students near her college in Somerset. “Sarah is independent and copes with life in a way we could never have imagined just after she was born,” says Andy.
It is a reassuring story, although one major worry still besets the Merriman family: Sarah’s long-term future and her susceptibility to Alzheimer’s disease, a form of dementia that leads to complete loss of memory, speech and awareness and which is closely linked to Down’s syndrome. Among members of the general population, the risk of getting Alzheimer’s before the age of 65 is less than 5%. For a person with Down’s syndrome the figure is 50%.
Could Down’s syndrome point the way to preventing Alzheimer’s disease?
Chronic Stress During Pregnancy Prevents Brain Benefits of Motherhood
(Credit: Oleg Zabielin / Shutterstock)
A new study in animals shows that chronic stress during pregnancy prevents brain benefits of motherhood, a finding that researchers suggest could increase understanding of postpartum depression.
Rat mothers showed an increase in brain cell connections in regions associated with learning, memory and mood. In contrast, the brains of mother rats that were stressed twice a day throughout pregnancy did not show this increase.
The researchers were specifically interested in dendritic spines – hair-like growths on brain cells that are used to exchange information with other neurons.
Previous animal studies conducted by lead author Benedetta Leuner of Ohio State University showed that an increase of dendritic spines in new mothers’ brains was associated with improved cognitive function on a task that requires behavioral flexibility – in essence, enabling more effective multitasking. The dendritic spines increased by about 20 percent in these brain regions in new mothers, according to her findings.
The stress in this new study negated those brain benefits of motherhood, causing the stressed rats’ brains to match brain characteristics of animals that had no reproductive or maternal experience.
The stressed rats also had less physical interaction with their babies than did unstressed rats, a behavior observed in human mothers who experience postpartum depression.
“Animal mothers in our research that are unstressed show an increase in the number of connections between neurons. Stressed mothers don’t,” said Leuner, assistant professor of psychology and neuroscience at Ohio State and lead author of the study. “We think that makes the stressed mothers more vulnerable. They don’t have the capacity for brain plasticity that the unstressed mothers do, and somehow that’s contributing to their susceptibility to depression.”
(Source: newswise.com)
Relapse or recovery? Neuroimaging predicts course of substance addiction treatment
An Indiana University study has provided preliminary evidence that by measuring brain activity through the use of neuroimaging, researchers can predict who is likely to have an easier time getting off drugs and alcohol, and who will need extra help.
"We can also see how brain activity changes as people recover from their addictions," said Joshua Brown, assistant professor in the Department of Psychological and Brain Sciences at Indiana University Bloomington, part of the College of Arts and Sciences.
The chronic occurrence of relapse underscores the need for improved methods of treatment and relapse prevention. One potential cause for relapse is deficient self-regulatory control over behavior and decision-making. Specifically this lack of self-regulatory ability in substance dependent individuals has been associated with dysfunction of a mesolimbic-frontal brain network. Reduced activity within this self-regulatory brain network has previously been implicated in relapse, but the specific relationship between this network, self-regulatory ability and recovery is yet to be determined.
What You Hear Could Depend on What Your Hands are Doing
A new finding could lead to strategies for treating speech loss after a stroke and helping children with dyslexia.
New research links motor skills and perception, specifically as it relates to a second finding—a new understanding of what the left and right brain hemispheres “hear.” Georgetown University Medical Center researchers say these findings may eventually point to strategies to help stroke patients recover their language abilities, and to improve speech recognition in children with dyslexia.
The study, presented at Neuroscience 2012, the annual meeting of the Society for Neuroscience, is the first to match human behavior with left brain/right brain auditory processing tasks. Before this research, neuroimaging tests had hinted at differences in such processing.
“Language is processed mainly in the left hemisphere, and some have suggested that this is because the left hemisphere specializes in analyzing very rapidly changing sounds,” says the study’s senior investigator, Peter E. Turkeltaub, M.D., Ph.D., a neurologist in the Center for Brain Plasticity and Recovery. This newly created center is a joint program of Georgetown University and MedStar National Rehabilitation Network.
Turkeltaub and his team hid rapidly and slowly changing sounds in background noise and asked 24 volunteers to simply indicate whether they heard the sounds by pressing a button.
“We asked the subjects to respond to sounds hidden in background noise,” Turkeltaub explained. “Each subject was told to use his or her right hand to respond during the first 20 sounds, then the left hand for the next 20 second, then right, then left, and so on.”
He says when a subject was using their right hand, they heard the rapidly changing sounds more often than when they used their left hand, and vice versa for the slowly changing sounds.
“Since the left hemisphere controls the right hand and vice versa, these results demonstrate that the two hemispheres specialize in different kinds of sounds—the left hemisphere likes rapidly changing sounds, such as consonants, and the right hemisphere likes slowly changing sounds, such as syllables or intonation,” Turkeltaub explains.
“These results also demonstrate the interaction between motor systems and perception. It’s really pretty amazing. Imagine you’re waving an American flag while listening to one of the presidential candidates. The speech will actually sound slightly different to you depending on whether the flag is in your left hand or your right hand.”
Ultimately, Turkeltaub hopes that understanding the basic organization of auditory systems and how they interact with motor systems will help explain why language resides in the left hemisphere of the brain, and will lead to new treatments for language disorders, like aphasia (language difficulties after stroke or brain injury) or dyslexia.
“If we can understand the basic brain organization for audition, this might ultimately lead to new treatments for people who have speech recognition problems due to stroke or other brain injury. Understanding better the specific roles of the two hemispheres in auditory processing will be a big step in that direction. If we find that people with aphasia, who typically have injuries to the left hemisphere, have difficulty recognizing speech because of problems with low-level auditory perception of rapidly changing sounds, maybe training the specific auditory processing deficits will improve their ability to recognize speech,” Turkeltaub concludes.
(Source: explore.georgetown.edu)
Study shows old adage ‘sleep on it’ is true – but only if it’s a really difficult problem
A new study from Lancaster University has found that sleeping on a problem really can help people to find a solution.
The study, published online this week in the journal Memory & Cognition, tested whether sleep or time spent awake worked best in helping people find the solutions to a range of problem solving tasks.
The authors of the study - Ut Na Sio, Padraic Monaghan and Tom Ormerod all from the Centre for Research in Human Development and Learning at Lancaster’s Department of Psychology - concluded that sleep facilitates problem solving but this has its primary effect for harder problems.
Professor Padraic Monaghan said: “We’ve known for years that sleep has a profound effect on our ability to be creative and find new solutions to problems. Our study shows that this sleep effect is greatest when the problems facing us are difficult. Sleep appears to help us solve problems by accessing information that is remote to the initial problem, that may not be initially brought to mind. Sleep has been proposed to ‘spread activation’ to the solution that is initially distant from our first attempts at the problem. The advice stemming from this and related research is to leave a problem aside if you’re stuck, and get some sleep if it’s a really difficult problem.”
More than Just ‘Zoning Out’ – Psychological Science Examines the Cognitive Processes Underlying Mind Wandering
It happens innocently enough: One minute you’re sitting at your desk, working on a report, and the next minute you’re thinking about how you probably need to do laundry and that you want to try the new restaurant down the street. Mind wandering is a frequent and common occurrence. And while mind wandering in certain situations – in class, for example – can be counterproductive, some research suggests that mind wandering isn’t necessarily a bad thing.
New research published in the journals of the Association for Psychological Science explores mind wandering in various contexts, examining how mind wandering is related to cognitive processes involved in working memory and executive control.
Neural-Like Stem Cells From Muscle Tissue May Hold Key to Cell Therapies for Neurodegenerative Diseases
Scientists at Wake Forest Baptist Medical Center have taken the first steps to create neural-like stem cells from muscle tissue in animals. Details of the work are published in two complementary studies published in the September online issues of the journals Experimental Cell Research and Stem Cell Research.
“Reversing brain degeneration and trauma lesions will depend on cell therapy, but we can’t harvest neural stem cells from the brain or spinal cord without harming the donor,” said Osvaldo Delbono, M.D., Ph.D., professor of internal medicine at Wake Forest Baptist and lead author of the studies.
“Skeletal muscle tissue, which makes up 50 percent of the body, is easily accessible and biopsies of muscle are relatively harmless to the donor, so we think it may be an alternative source of neural-like cells that potentially could be used to treat brain or spinal cord injury, neurodegenerative disorders, brain tumors and other diseases, although more studies are needed.”
In an earlier study, the Wake Forest Baptist team isolated neural precursor cells derived from skeletal muscle of adult transgenic mice (PLOS One, Feb.3, 2011).
In the current research, the team isolated neural precursor cells from in vitro adult skeletal muscle of various species including non-human primates and aging mice, and showed that these cells not only survived in the brain, but also migrated to the area of the brain where neural stem cells originate.
Another issue the researchers investigated was whether these neural-like cells would form tumors, a characteristic of many types of stem cells. To test this, the team injected the cells below the skin and in the brains of mice, and after one month, no tumors were found.
“Right now, patients with glioblastomas or other brain tumors have very poor outcomes and relatively few treatment options,” said Alexander Birbrair, a doctoral student in Delbono’s lab and first author of these studies. “Because our cells survived and migrated in the brain, we may be able to use them as drug-delivery vehicles in the future, not only for brain tumors but also for other central nervous system diseases.”
In addition, the Wake Forest Baptist team is now conducting research to determine if these neural-like cells also have the capability to become functioning neurons in the central nervous system.
(Source: newswise.com)
Study links hippocampus with unconscious bias
The hippocampus is an area of the brain known to be one in which links between memories are formed, but until now it was not known that this brain region is involved in steering the brain towards making particular choices over others when faced with new decisions for which we have no previous experiences to draw on.
In a paper published in the journal Science, research psychologists G. Elliott Wimmer and Daphna Shohamy of Columbia University in New York report on their study, which used functional magnetic resonance imaging (fMRI) of regions of the brain. In the study, they asked 31 volunteers to complete a three-part task while in the machine. Throughout the task their brain activity was determined by the fMRI.
The results suggest that several areas of the brain are involved in evaluating new stimuli and associating them with previous memories, but the process is strongly associated with the hippocampus.
The findings could have application, for example, in the design of new products, which could incorporate aspects of earlier products (such as color, logo or font) to stimulate the association and produce an unconscious bias towards those products over other equally new products.
The findings also suggest that misguided biases such as racism could stem from unconscious associations. (Guilt by association is a commonly known bias.) These biases have long been known, but the current study clearly shows their association with the hippocampus.
Transplantation of Embryonic Neurons Raises Hope for Treating Brain Diseases
The unexpected survival of embryonic neurons transplanted into the brains of newborn mice in a series of experiments at the University of California, San Francisco (UCSF) raises hope for the possibility of using neuronal transplantation to treat diseases like Alzheimer’s, epilepsy, Huntington’s, Parkinson’s and schizophrenia.
The experiments, described this week in the journal Nature, were not designed to test whether embryonic neuron transplants could effectively treat any specific disease. But they provide a proof-of-principle that GABA-secreting interneurons, a type of brain cell linked to many different neurological disorders, can be added in significant numbers into the brain and can survive without affecting the population of endogenous interneurons.
The survival of these cells after transplantation in numbers far greater than expected came as a shock to the team, which was led by UCSF professor Arturo Alvarez-Buylla, PhD, and former UCSF graduate student Derek Southwell, MD, PhD.
The prevailing theory held that the survival of developing neurons is something like a game of musical chairs. The brain has limited capacity for these cells, forcing them to compete with each other for the few available slots. Only those that find a place to “sit” (and receive survival signals derived from other cell types) will survive when the music stops. The rest die a withering death.