Posts tagged brain function
Articles and news from the latest research reports.
New model could lead to improved treatment for early stage Alzheimer’s
Researchers at the University of Florida and The Johns Hopkins University have developed a line of genetically altered mice that model the earliest stages of Alzheimer’s disease. This model may help scientists identify new therapies to provide relief to patients who are beginning to experience symptoms.
The researchers report their findings in the current issue of The Journal of Neuroscience.
“The development of this model could help scientists identify new ways to enhance brain function in patients in the early stages of the disease,” said David Borchelt, UF professor of neuroscience in the Evelyn F. and William L. McKnight Brain Institute and director of the SantaFe HealthCare Alzheimer’s Disease Research Center. “Such therapies could preserve brain function longer and delay the appearance of more severe symptoms that leave patients unable to care for themselves.”
In the early stages of Alzheimer’s disease, people struggle with and fail to learn new games, rules or technologies because their cognitive flexibility decreases. The degenerative disease continues with memory loss and the decline of other brain functions.
The researchers worked with mice that had specially designed gene fragments derived from bacteria and from humans that allowed the investigators to control the production of a small peptide. The peptide, called amyloid beta peptide, is a short chain of amino acids. Accumulations of this particular peptide in the brain as lesions called plaques occur early in the progression of Alzheimer’s disease and seem to trigger the early memory problems.
The team regulated the expression of the peptide using antibiotics — when the animals stopped taking the antibiotic, the peptide-producing gene turned on and caused the mice to develop the plaques found in Alzheimer’s patients. After the mice had developed the Alzheimer pathology, the researchers turned the gene back off and observed that the mice showed persistent memory problems that resemble the early stages of the disease.
“This model may be useful to researchers to test drugs that could help with symptoms of early stage Alzheimer’s disease,” Borchelt said.This research is funded by the National Institute of Neurological Disease and Stroke of the National Institutes of Health, and the SantaFe HealthCare Alzheimer’s Disease Research Center of the University of Florida.
Authors: Develop digital games to improve brain function and well-being
Neuroscientists should help to develop compelling digital games that boost brain function and improve well-being, say two professors specializing in the field in a commentary article published in the science journal Nature.
In the Feb. 28 issue, the two — Daphne Bavelier of the University of Rochester and Richard J. Davidson of the University of Wisconsin-Madison — urge game designers and brain scientists to work together to design new games that train the brain, producing positive effects on behavior, such as decreasing anxiety, sharpening attention and improving empathy. Already, some video games are designed to treat depression and to encourage cancer patients to stick with treatment, the authors note.
Davidson is founder and chair of the Center for Investigating Healthy Minds at the UW’s Waisman Center. Bavelier is a professor in the Department of Brain and Cognitive Sciences at Rochester.
Video game usage, which continues to rise among American children, has been associated with a number of negative outcomes, such as obesity, aggressiveness, antisocial behavior and, in extreme cases, addiction. “At the same time, evidence is mounting that playing games can have a beneficial effects on the brain,” the authors write.
Last year, Bavelier and Davidson presided over a meeting at the White House in which neuroscientists met with entertainment media experts to discuss ways of using interactive technology such as video games to further understanding of brain functions, as well as to provide new, engaging tools for boosting attention and well-being.
Bavelier’s work is focused on how humans learn and how the brain adapts to changes in experience, either by nature (as in deafness) or by training (such as playing video games). Her lab investigates how new media, including video games, can be leveraged to foster learning and brain plasticity.
Davidson, who studies emotion and the brain, is leading a project in collaboration with UW-Madison’s Games + Learning + Society to develop two video games designed to help middle school students develop social and emotional skills, such as empathy, cooperation, mental focus and self-regulation.
"Gradually, this work will begin to document the burning social question of how technology is having an impact on our brains and our lives, and enable us to make evidence-based choices about the technologies of the future, to produce a new set of tools to cultivate positive habits of mind," the authors conclude.
Psychogenic diseases, formerly known as ‘hysterical’ illnesses, can have many severe symptoms such as painful cramps or paralysis but without any physical explanation. However, new research from the University of Cambridge and UCL (University College London) suggests that individuals with psychogenic disease, that is to say physical illness that stems from emotional or mental stresses, do have brains that function differently. The research was published today, 25 February, in the journal Brain.
Psychogenic diseases may look very similar to illnesses caused by damage to nerves, the brain or the muscles, or similar to genetic diseases of the nervous system. However, unlike organic diseases, psychogenic diseases do not have any apparent physical cause, making them difficult to diagnose and even more difficult to treat.
“The processes leading to these disorders are poorly understood, complex and highly variable. As a result, treatments are also complex, often lengthy and in many cases there is poor recovery. In order to improve treatment of these disorders, it is important to first understand the underlying mechanism,” said Dr James Rowe from the University of Cambridge.
The study looked at people with either psychogenic or organic dystonia, as well as healthy people with no dystonia. Both types of dystonia caused painful and disabling muscle contractions affecting the leg. The organic patient group had a gene mutation (the DYT1 gene) that caused their dystonia. The psychogenic patients had the symptoms of dystonia but did not have any physical explanation for the disease, even after extensive investigations.
The scientists performed PET brain scans on the volunteers at UCL, to measure the blood flow and brain activity of both of the groups, and healthy volunteers. The participants were scanned with three different foot positions: resting, moving their foot, and holding their leg in a dystonic position. The electrical activity of the leg muscles was measured at the same time to determine which muscles were engaged during the scans.
The researchers found that the brain function of individuals with the psychogenic illness was not normal. The changes were, however, very different from the brains of individuals with the organic (genetic) disease.
Dr Anette Schrag, from UCL, said: “Finding abnormalities of brain function that are very different from those in the organic form of dystonia opens up a way for researchers to learn how psychological factors can, by changing brain function, lead to physical problems.”
Dr Rowe added: “What struck me was just how very different the abnormal brain function was in patients with the genetic and the psychogenic dystonia. Even more striking was that the differences were there all the time, whether the patients were resting or trying to move.”
Additionally, the researchers found that one part of the brain previously thought to indicate psychogenic disease is unreliable: abnormal activity of the prefrontal cortex was thought to be the hallmark of psychogenic diseases. In this study, the scientists showed that this abnormality is not unique to psychogenic disease, since activity was also present in the patients with the genetic cause of dystonia when they tried to move their foot.
Dr Arpan Mehta, from the University of Cambridge, said: “It is interesting that, despite the differences, both types of patient had one thing in common - a problem at the front of the brain. This area controls attention to our movements and although the abnormality is not unique to psychogenic dystonia, it is part of the problem.”
This type of illness is very common. Dr Schrag said: “One in six patients that see a neurologist has a psychogenic illness. They are as ill as someone with organic disease, but with a different cause and different treatment needs. Understanding these disorders, diagnosing them early and finding the right treatment are all clearly very important. We are hopeful that these results might help doctors and patients understand the mechanism leading to this disorder, and guide better treatments.”
Shedding New Light on Infant Brain Development
A new study by Columbia Engineering researchers finds that the infant brain does not control its blood flow in the same way as the adult brain. The findings, which the scientists say could change the way researchers study brain development in infants and children, are published in the February 18 Early Online edition of Proceedings of the National Academy of Sciences (PNAS).
“The control of blood flow in the brain is very important,” says Elizabeth Hillman, associate professor of biomedical engineering and of radiology, who led the research study in her Laboratory for Functional Optical Imaging at Columbia. “Not only are regionally specific increases in blood flow necessary for normal brain function, but these blood-flow increases form the basis of signals measured in fMRI, a critical imaging tool used widely in adults and children to assess brain function. Many prior fMRI studies have overlooked the possibility that the infant brain controls blood flow differently.”
“Our results are fascinating,” says Mariel Kozberg, a neurobiology MD-PhD candidate who works under Hillman and is the lead author of the PNAS paper. “We found that the immature brain does not generate localized blood-flow increases in response to stimuli. By tracking changes in blood-flow control with increasing age, we observed the brain gradually developing its ability to increase local blood flow and, by adulthood, generate a large blood-flow response.”
The study results suggest that fMRI experiments in infants and children should be carefully designed to ensure that maturation of blood-flow control can be delineated from changes in neuronal development. “On the other hand,” says Hillman, “our findings also suggest that vascular development may be an important new factor to consider in normal and abnormal brain development, so our findings could represent new markers of normal and abnormal brain development that could potentially be related to a range of neurological or even psychological conditions.”
UCSB Study of Cocaine Addiction Reveals Targets for Treatment
Scientists at UC Santa Barbara are researching cocaine addiction, part of a widespread problem, which, along with other addictions, costs billions of dollars in damage to individuals, families, and society. Laboratory studies at UCSB have revealed that the diminished brain function and learning impairment that result from cocaine addiction can be treated –– and that learning can be restored.
Karen Szumlinski, a professor in the Department of Psychological & Brain Sciences at UCSB, and her colleagues Osnat Ben-Shahar and Tod Kippin, have worked in the field of addiction for many years. Senior author of a paper on this topic published recently in The Journal of Neuroscience, Szumlinski is particularly interested in the part of the brain called the prefrontal cortex, where the process of “executive function” –– or decision-making –– is located. This area is involved in directing one’s behavior in an appropriate manner, and in controlling behavior.
With her research team, Szumlinski discovered that a drug that stimulates a certain type of glutamate receptor –– when aimed at the prefrontal cortex –– could restore learning impairment in rats with simulated cocaine addiction.
"Needless to say, this (the prefrontal cortex) is one of the last parts of the brain to develop, and, of relevance to our students, continues to develop through about age 25 to 28," said Szumlinski.
Szumlinski explained that in the prefrontal cortex there seems to be “hypo-frontality,” or reduced functioning, in drug addicts, as well as in patients with a range of neuropsychiatric diseases, including schizophrenia, depression, and attention deficit disorder.
Szumlinski calls the prefrontal cortex a late-developing brain area that is critical for making proper decisions, and inhibiting behavior. “You damage this brain region and you lose the ability to self-regulate, you make impulsive decisions like engaging in risky sexual behavior or drug-taking, you basically go off the deep end in terms of function,” she said. “So we were very much interested in how drugs of abuse impact the prefrontal cortex, given that human drug addicts show deficits in this brain area when you put them into a scanner. They show hypo-activity.” She said this hypo-activity, or hypo-frontality, might relate to a neurotransmitter that scientists know is involved in exciting the brain.
A key question, according to Szumlinski, is this: “Was that hypo-frontality there in the first place, and that’s why they became an addict; or did the drugs change their prefrontal cortext, to cause it to become hypo-functioning and thus they’re not able to control their drug use? You can’t parse that out in humans. So that’s why we turn then to animal models of the disorder, and we do have this rat model that we use in the paper.”
Szumlinski pointed out a key difficulty in the development of treatments for addiction: There is little money targeted to the study of this disease. Hence, in addition to studying the brain mechanisms that are involved, she is joining forces with researchers who study other neurological diseases that are well-funded, to help find cures. She hopes that government approval of new drugs for these other diseases would eventually make the drugs available for clinical trials to study their effects on cocaine addiction.
(Image: iStock)
Western University-led research debunks the IQ myth
After conducting the largest online intelligence study on record, a Western University-led research team has concluded that the notion of measuring one’s intelligence quotient or IQ by a singular, standardized test is highly misleading.
The findings from the landmark study, which included more than 100,000 participants, were published in the journal Neuron.
Utilizing an online study open to anyone, anywhere in the world, the researchers asked respondents to complete 12 cognitive tests tapping memory, reasoning, attention and planning abilities, as well as a survey about their background and lifestyle habits.
"The uptake was astonishing," says Owen, the Canada Excellence Research Chair in Cognitive Neuroscience and Imaging and senior investigator on the project. "We expected a few hundred responses, but thousands and thousands of people took part, including people of all ages, cultures and creeds from every corner of the world."
The results showed that when a wide range of cognitive abilities are explored, the observed variations in performance can only be explained with at least three distinct components: short-term memory, reasoning and a verbal component.
No one component, or IQ, explained everything. Furthermore, the scientists used a brain scanning technique known as functional magnetic resonance imaging (fMRI), to show that these differences in cognitive ability map onto distinct circuits in the brain.
With so many respondents, the results also provided a wealth of new information about how factors such as age, gender and the tendency to play computer games influence our brain function.
"Regular brain training didn’t help people’s cognitive performance at all yet aging had a profound negative effect on both memory and reasoning abilities," says Owen.
Hampshire adds, “Intriguingly, people who regularly played computer games did perform significantly better in terms of both reasoning and short-term memory. And smokers performed poorly on the short-term memory and the verbal factors, while people who frequently suffer from anxiety performed badly on the short-term memory factor in particular”.
To continue the groundbreaking research, the team has launched a new version of the tests at http://www.cambridgebrainsciences.com/theIQchallenge
"To ensure the results aren’t biased, we can’t say much about the agenda other than that there are many more fascinating questions about variations in cognitive ability that we want to answer," explains Hampshire.
(Image by Lasse Kristensen/Shutterstock)
Excessive alcohol when you’re young could have lasting impacts on your brain
Alcohol misuse in young people causes significant changes in their brain function and structure. This and other findings were recently reviewed by Dr Daniel Hermens from the University of Sydney’s Brain and Mind Research Institute in the journal Cortex.
"Young people are particularly vulnerable to the damaging effects of alcohol misuse," said Dr Hermens.
Most people have their first alcoholic drink during adolescence and while they drink less frequently than adults, they tend to drink more on each occasion - binge drinking.
The early functional signs of brain damage from alcohol misuse are visual, learning, memory and executive function impairments. These functions are controlled by the hippocampus and frontal structures of the brain, which are not fully mature until around 25 years of age.
Structural signs of alcohol misuse include shrinking of the brain and significant changes to white matter.
In his review, Dr Hermens notes that changes in a young person’s brain caused by alcohol misuse could either represent a predisposition (genetic or environmental) to alcohol misuse, or a marker for future risk of ongoing misuse. Whichever it is, there is no doubt that the more frequent the alcohol misuse, the greater the damage and the less likely the brain is to recover from that damage.
"When the toxicity of alcohol stops your brain from laying down new memories, you experience a blackout," said Dr Hermens. Young people who binge drink may only drink once a week, but on a massive night out they may have three to four blackouts, which begins to cause serious damage to their brain.
One of the best predictors of a person having problems with alcohol is their earliest age of first use. But changing the legal drinking age is not the answer. In Australia the legal drinking age is 18, three years earlier than in the US. Despite the difference in legal drinking age, the age of first use is the same between the two countries.
Another key factor affecting young people who drink is mental health, “poor mental health more than doubles a young person’s risk of alcohol and other substance misuse” says Dr Hermens.
The solution lies in education, treatment and prevention. Dr Hermens and his team have been working with NSW Health to prepare a set of guidelines for health carers to identify and respond to early stages of brain impairment in young people resulting from alcohol misuse. They are currently working on a set of educational charts that inform young people of the risks of irresponsible drinking.
It may be possible to use cognitive remediation to change the drinking habits of young drinkers and prevent relapse. At the same time, vitamin supplements or other medicines may effectively treat some of the structural changes, and it may be possible to develop protective agents that can prevent young brains from the damaging effects of alcohol.
"More work needs to be done in this area. Excessive alcohol use accounts for 4 percent of the global burden of disease. We would save a lot of money and improve the quality of life for millions of people if we could prevent the mental and physical problems associated with alcohol misuse" said Dr Hermens.
Early treatment sparks striking brain changes in autism
When given early treatment, children with autism spectrum disorders (ASD) made significant improvements in behavior, communication, and most strikingly, brain function, Yale School of Medicine researchers report in a new study.
The study was published in the current issue of the Journal of Autism and Developmental Disorders by Yale Child Study Center researchers Dr. Fred Volkmar, Kevin A. Pelphrey, and their colleagues.
The results suggest that brain systems supporting social perception respond well to an early intervention behavioral program called pivotal response treatment. This treatment includes parent training, and employs play in its methods.
Multivitamin lifts brain activity
A daily multivitamin supplement may improve brain efficiency in older women, according to new research from Swinburne University of Technology.
Centre for Human Psychopharmacology researcher at Swinburne, Dr Helen Macpherson’s four month study of the commercial product Swisse Women’s Ultivite 50+ found some evidence that multivitamin supplements may influence cognitive function by altering electrical activity in the brain.
"The main finding of the study was that 16 weeks supplementation with the Swisse Women’s 50+ multivitamin modulated brain activity," Dr Macpherson said.
"This is an important result as it shows there are direct effects of multivitamins on the brain.
"Previous research has used measures of behaviour to determine whether multivitamins can affect brain function, but this is the first trial to directly measure brain activity."
The study was conducted over 16 weeks with 56 women aged between 64 and 79 who were concerned about their memory or experiencing memory difficulties. They were randomly assigned to take the multivitamin supplement or a placebo daily.
Volunteers underwent a recording of their brain electrical activity whilst performing a spatial working memory task.
The research was published in Physiology and Behavior.
A previous paper published in Psychopharmacology reported that multivitamin supplementation improved behavioural performance on a similar task, in the same group of participants.
The study concluded that 16 weeks of supplementation with a combined multivitamin, mineral and herbal formula may benefit memory, by enabling the brain to work in a more efficient way.
"When considered with our other findings of benefits to memory performance, there is increasing evidence that multivitamins may be useful to combat cognitive decline in the elderly," Dr Macpherson said.
(Source: swinburne.edu.au)
Diabetes Raises Levels of Proteins Linked to Alzheimer’s Features
Growing evidence suggests that there may be a link between diabetes and Alzheimer’s disease, but the physiological mechanisms by which diabetes impacts brain function and cognition are not fully understood. In a new study published in Aging Cell, researchers at the Salk Institute for Biological Studies show, for the first time, that diabetes enhances the development of aging features that may underlie early pathological events in Alzheimer’s.
Specifically, the Salk team found increases in two hallmarks of Alzheimer’s-accumulations of amyloid beta (Abeta) and tau protein-in the brains of diabetic mice, especially in cells surrounding blood vessels. Abeta, the misfolded peptide that is thought in part to cause Alzheimer’s disease, aggregated inside astrocytes, star-shaped brain cells that, upon interaction with Abeta, release inflammatory molecules that can destroy neurons. Previously, this had not been shown in mouse models of type 1 diabetes (T1D).
"Our study supports and extends the links between diabetes, aging and Alzheimer’s," says senior author Pamela Maher, a senior staff scientist in Salk’s Laboratory of Cellular Neurobiology. "We show that type 1 diabetes increases vascular-associated amyloid beta buildup in the brain and causes accelerated brain aging."
The findings suggest that the neurovascular system may be a good candidate for new therapeutic targets to treat Alzheimer’s in the early stages of the disease.