Posts tagged brain
Articles and news from the latest research reports.
Link between creativity and mental illness confirmed
People in creative professions are treated more often for mental illness than the general population, there being a particularly salient connection between writing and schizophrenia. This according to researchers at Karolinska Institutet, whose large-scale Swedish registry study is the most comprehensive ever in its field.
Last year, the team showed that artists and scientists were more common amongst families where bipolar disorder and schizophrenia is present, compared to the population at large. They subsequently expanded their study to many more psychiatric diagnoses - such as schizoaffective disorder, depression, anxiety syndrome, alcohol abuse, drug abuse, autism, ADHD, anorexia nervosa and suicide - and to include people in outpatient care rather than exclusively hospital patients.
The present study tracked almost 1.2 million patients and their relatives, identified down to second-cousin level. Since all were matched with healthy controls, the study incorporated much of the Swedish population from the most recent decades. All data was anonymized and cannot be linked to any individuals.
The results confirmed those of their previous study: certain mental illness - bipolar disorder - is more prevalent in the entire group of people with artistic or scientific professions, such as dancers, researchers, photographers and authors. Authors specifically also were more common among most of the other psychiatric diseases (including schizophrenia, depression, anxiety syndrome and substance abuse) and were almost 50 per cent more likely to commit suicide than the general population.
The researchers also observed that creative professions were more common in the relatives of patients with schizophrenia, bipolar disorder, anorexia nervosa and, to some extent, autism. According to Simon Kyaga, consultant in psychiatry and doctoral student at the Department of Medical Epidemiology and Biostatistics, the results give cause to reconsider approaches to mental illness.
"If one takes the view that certain phenomena associated with the patient’s illness are beneficial, it opens the way for a new approach to treatment," he says. "In that case, the doctor and patient must come to an agreement on what is to be treated, and at what cost. In psychiatry and medicine generally there has been a tradition to see the disease in black-and-white terms and to endeavour to treat the patient by removing everything regarded as morbid."
(Source: ki.se)
Neuroscientists find Broca’s area is really two subunits, each with its own function
A century and a half ago, French physician Pierre Paul Broca found that patients with damage to part of the brain’s frontal lobe were unable to speak more than a few words. Later dubbed Broca’s area, this region is believed to be critical for speech production and some aspects of language comprehension.
However, in recent years neuroscientists have observed activity in Broca’s area when people perform cognitive tasks that have nothing to do with language, such as solving math problems or holding information in working memory. Those findings have stimulated debate over whether Broca’s area is specific to language or plays a more general role in cognition.
A new study from MIT may help resolve this longstanding question. The researchers, led by Nancy Kanwisher, the Walter A. Rosenblith Professor of Cognitive Neuroscience, found that Broca’s area actually consists of two distinct subunits. One of these focuses selectively on language processing, while the other is part of a brainwide network that appears to act as a central processing unit for general cognitive functions.
"I think we’ve shown pretty convincingly that there are two distinct bits that we should not be treating as a single region, and perhaps we shouldn’t even be talking about ‘Broca’s area’ because it’s not a functional unit," says Evelina Fedorenko, a research scientist in Kanwisher’s lab and lead author of the new study, which recently appeared in the journal Current Biology.
New study shows that even your fat cells need sleep
In a study that challenges the long-held notion that the primary function of sleep is to give rest to the brain, researchers have found that not getting enough shut-eye has a harmful impact on fat cells, reducing by 30 percent their ability to respond to insulin, a hormone that regulates energy.
Sleep deprivation has long been associated with impaired brain function, causing decreased alertness and reduced cognitive ability. The latest finding—published by University of Chicago Medicine researchers in the Oct. 16 issue of the Annals of Internal Medicine—is the first description of a molecular mechanism directly connecting sleep loss to the disruption of energy regulation in humans, a process that can lead over time to weight gain, diabetes and other health problems. The study suggests that sleep’s role in energy metabolism is at least as important as it is in brain function.
"We found that fat cells need sleep to function properly," said study author Matthew Brady, PhD, associate professor of medicine and vice-chair of the Committee on Molecular Metabolism and Nutrition at the University of Chicago.
A tool to quantify consciousness?
Assessing consciousness may seem like the ultimate exercise in subjectivity, but some researchers are moving closer to what they call an objective measure.
The goal is to provide clearer information for families with loved ones living in vegetative or minimally conscious states — conditions that are often caused by brain trauma or cardiac arrest.
“We really need to find a way to be able to measure consciousness reliably,” says Melanie Boly, a postdoctoral fellow at the Belgian National Fund for Research in Liege, Belgium. “For the family, this changes everything,” says Boly, who presented her team’s research on 14 October at the Society for Neuroscience meeting in New Orleans, Louisiana.
Vegetative patients make only reflexive movements and appear insensitive to their surroundings, while minimally conscious patients can make some purposeful movements and even feel pain. Clinically, the differences between these patients can be difficult even for experienced physicians to discern. But legally, the differences are clear.
In 2011, the UK court system denied a family’s request to end life support for their daughter after additional tests revised her initial diagnosis from ‘vegetative’ to ‘minimally conscious’.
To derive a numerical measure of consciousness, Boly and her colleagues pulsed subjects’ heads with a brief electromagnetic wave, then measured neural responses using electrodes stuck to the scalp.
In 32 healthy, awake people, the electromagnetic impulse sent complex patterns of electrical activity reverberating throughout the brain. In healthy sleeping people, or people under general anaesthesia, the brain displayed shorter, simpler responses that stayed closer to the site of the initial stimulation. The researchers quantified these differences in a measure of response complexity.
In six patients diagnosed as vegetative, the electromagnetic pulse elicited responses with complexity indices similar to those in sleeping or anaesthetized healthy subjects. Twelve minimally conscious patients showed slightly more complex responses. And two ‘locked-in’ patients — people who are fully conscious but unable to move or communicate — showed complexity indices similar to healthy, awake subjects.
Boly and her colleagues have previously noted some of these differences across patient groups but with poor reliability for individual patients. With the complexity index, which combines several aspects of the brain’s response, she says, “this is the first time we really have a measure that works at a single-subject level.”
“It’s not going to supplant a clinical assessment,” says Nicholas Schiff, a neurologist at the Weill Cornell Medical College in New York. But he says the complexity index could become a valuable tool for adding some certainty to the subjective process of evaluating patient consciousness.
“I personally would welcome a test that could provide us with objective measurements,” says David Okonkwo, clinical director of the Brain Trauma Research Center at the University of Pittsburgh in Pennsylvania. However, he said much more testing is needed to tell whether the complexity index meets that standard.
“We need more patients,” agrees Boly, “but it’s extremely promising.”
(Source: blogs.nature.com)
New merciful treatment method for children with brain tumours
Children who undergo brain radiation therapy run a significant risk of suffering from permanent neurocognitive adverse effects. These adverse effects are due to the fact that the radiation often encounters healthy tissue. This reduces the formation of new cells, particularly in the hippocampus – the part of the brain involved in memory and learning.
Researchers at the University of Gothenburg’s Sahlgrenska Academy have used a model study to test newer radiation therapy techniques which could reduce these harmful adverse effects. The researchers based their study on a number of paediatric patients who had undergone conventional radiation treatment for medulloblastoma, a form of brain tumour that almost exclusively affects children, and simulated treatment plans using proton therapy techniques and newer photon therapy techniques.
Each treatment plan was personalised by physician Malin Blomstrand, physicist Patrik Brodin and their colleagues. The results show that the risk of neurocognitive adverse effects can be reduced significantly using the new radiation treatment techniques, particularly proton therapy.
“This could mean a better quality of life for children who are forced to undergo brain radiation therapy,” says Malin Blomstrand.
A Future Without Seizures
Five-year-old Nathan Kalina of Naperville will enter kindergarten this fall after spending the summer in day camp: playing games, enjoying field trips, and romping in the pool. He loves playing with action figures and acting out scenes from his favorite movies.
The scene two years ago was very different. After getting a few reports from daycare about unexplained falls, Nathan’s parents started to notice him having minor seizures. His mother, Megan, wasn’t too concerned at first; both she and her father had had childhood seizures and recovered from them without incident. Then came Nathan’s first tonic-clonic seizure (formerly known as a “grand mal” seizure), a major event involving his whole brain and body. A trip to a local emergency room for basic tests led to an electroencephalogram a few days later. All the while Nathan was having more seizures, large and small.
"We went from zero to crazy in a matter of days," Megan said.
Medication helped some. Nathan’s father David, a teacher in the Naperville schools, devoted his summer to adjusting Nathan’s regimen. But in the fall, the seizures ramped up again. One specialist suggested a high-fat ketogenic diet, which has been shown to help some children with epilepsy — but it didn’t help Nathan. “Feeding a 4-year-old picky eater on meat, cheese and cream was hard on us and started making him sick,” Megan said.
Evolution Mostly Driven by Brawn, Not Brains, Analysis Finds
The most common measure of intelligence in animals, brain size relative to body size, may not be as dependent on evolutionary selection on the brain as previously thought, according to a new analysis by scientists.
Brain size relative to body size has been used by generations of scientists to predict an animal’s intelligence. For example, although the human brain is not the largest in the animal kingdom in terms of volume or mass, it is exceptionally large considering our moderate body mass.
Now, a study by a team of scientists at UCL, the University of Konstanz, and the Max Planck Institute of Ornithology has found that the relationship between the two traits is driven by different evolutionary mechanisms in different animals.
Crucially, researchers have found that the most significant factor in determining relative brain size is often evolutionary pressure on body size, and not brain size. For example, the evolutionary history of bats reveals they decreased body size much faster than brain size, leading to an increase in relative brain size. As a result, small bats were able to evolve improved flying maneuvrability while maintaining the brainpower to handle foraging in cluttered environments.
This shows that relative brain size can not be used unequivocally as evidence of selection for intelligence. The study is published in the Proceedings of the National Academy of Sciences.
Researchers reveal first brain study of Temple Grandin
Temple Grandin, perhaps the world’s most famous person with autism, has exceptional nonverbal intelligence and spatial memory, and her brain has a host of structural and functional differences compared with the brains of controls, according to a presentation Saturday at the 2012 Society for Neuroscience annual meeting in New Orleans.
Grandin, professor of animal sciences at Colorado State University, is an outspoken advocate for autism research and awareness. She is known as a ‘savant,’ or a person who shows characteristic social deficits of autism and yet also has some exceptional abilities. For instance, she has extremely sharp visual acuity.
This is the first study to take a close look at Grandin’s brain, and one of the first to look at the brains of savants.
Developing brain is source of stability and instabilty in adolescence
Scientists are presenting new research on how the brain develops during the dynamic and vulnerable transition period from childhood to adulthood. The findings underscore the uniqueness of adolescence, revealing factors that may influence depression, decision-making, learning, and social relationships.
The findings were presented at Neuroscience 2012, the annual meeting of the Society for Neuroscience and the world’s largest source of emerging news about brain science and health.
The brain’s “reward system,” those brain circuits and structures that mediate the experience and pursuit of pleasure, figured prominently in several studies. The studies shed light on adolescents’ ability to control impulsivity and think through problems; reveal physical changes in the “social brain;” document connections between early home life and brain function in adolescence; and examine the impact of diet on depressive-like behavior in rodents.
Today’s new findings show that:
- Adolescents can throw impulsivity out the window when big rewards are at stake. The bigger the reward, the more thoughtful they can be, calling on important brain regions to gather and weigh evidence, and make decisions that maximize gains (BJ Casey, PhD).
- Rodents that receive an omega-3 fatty acid in their diets, from gestation through their early development, appear less vulnerable to depressive-like behaviors during adolescence (Christopher Butt, PhD).
- Depression in older adolescent boys may be associated with changes in communication between regions of the brain that process reward. At the same time, the study found possible connections between early emotional attachments — particularly with mothers — and later reward system function (Erika Forbes, PhD).
- Early cognitive stimulation appears to predict the thickness of parts of the human cortex in adolescence, and experiences at age four appear to have a greater impact than those at age eight (Martha Farah, PhD).
- During the span of adolescence, the volume of the “social brain” — those areas that deal with understanding other people — changes substantially, with notable gender differences (Kathryn Mills, BA).
"Advances in neuroscience continue to delve deeper and deeper into the unique and dynamically changing biology of the adolescent brain," said press conference moderator Jay Giedd, MD, of the National Institute of Mental Health, an expert on childhood and adolescent brain development. "The insights are beginning to elucidate the mechanisms that make the teen years a time of particular vulnerabilities but also a time of great opportunity."
(Source: sciencedaily.com)
Neuroscientists find the molecular “When” and “Where” of memory formation
Neuroscientists from New York University and the University of California, Irvine have isolated the “when” and “where” of molecular activity that occurs in the formation of short-, intermediate-, and long-term memories. Their findings, which appear in the journal the Proceedings of the National Academy of Sciences, offer new insights into the molecular architecture of memory formation and, with it, a better roadmap for developing therapeutic interventions for related afflictions.
“Our findings provide a deeper understanding of how memories are created,” explained the research team leader Thomas Carew, a professor in NYU’s Center for Neural Science and dean of NYU’s Faculty of Arts and Science. “Memory formation is not simply a matter of turning molecules on and off; rather, it results from a complex temporal and spatial relationship of molecular interaction and movement.”
Neuroscientists have previously uncovered different aspects of molecular signaling relevant to the formation of memories. But less understood is the spatial relationship between molecules and when they are active during this process.
To address this question, the researchers studied the neurons in Aplysia californica, the California sea slug. Aplysia is a model organism that is quite powerful for this type of research because its neurons are 10 to 50 times larger than those of higher organisms, such as vertebrates, and it possesses a relatively small network of neurons—characteristics that readily allow for the examination of molecular signaling during memory formation. Moreover, its coding mechanism for memories is highly conserved in evolution, and thus is similar to that of mammals, making it an appropriate model for understanding how this process works in humans.
The scientists focused their study on two molecules, MAPK and PKA, which earlier research has shown to be involved in many forms of memory and synaptic plasticity—that is, changes in the brain that occur after neuronal interaction. But less understood was how and where these molecules interacted.
To explore this, the researchers subjected the sea slugs to sensitization training, which induces increased behavioral reflex responsiveness following mild tail shock, or in this study, mild activation of the nerve form the tail. They then examined the subsequent molecular activity of both MAPK and PKA. Both molecules have been shown to be involved in the formation of memory for sensitization, but the nature of their interaction is less clear.
What they found was MAPK and PKA coordinate their activity both spatially and temporally in the formation of memories. Specifically, in the formation of intermediate-term (i.e., hours) and long-term (i.e., days) memories, both MAPK and PKA activity occur, with MAPK spurring PKA action. By contrast, for short-term memories (i.e., less than 30 minutes), only PKA is active, with no involvement of MAPK.
(Source: nyu.edu)