Posts tagged psychology
Articles and news from the latest research reports.
Kids who get migraine headaches are much more likely than other children to also have behavioral difficulties, including social and attention issues, and anxiety and depression. The more frequent the headaches, the greater the effect, according to research out now in the journal Cephalagia, published by SAGE.
Marco Arruda, director of the Glia Institute in São Paulo, Brazil, together with Marcelo Bigal of the Albert Einstein College of Medicine in New York studied 1,856 Brazilian children aged 5 to 11. The authors say that this is the first large, community based study of its kind to look at how children’s behavioural and emotional symptoms correlate with migraine and tension-type headaches (TTH), and to incorporate data on headache frequency.
Mayo Clinic Researchers Identify New Enzyme to Fight Alzheimer’s Disease
An enzyme that could represent a powerful new tool for combating Alzheimer’s disease has been discovered by researchers at Mayo Clinic in Florida. The enzyme — known as BACE2 — destroys beta-amyloid, a toxic protein fragment that litters the brains of patients who have the disease. The findings were published online Sept. 17 in the science journal Molecular Neurodegeneration.
Alzheimer’s disease is the most common memory disorder. It affects more that 5.5 million people in the United States. Despite the disorder’s enormous financial and personal toll, effective treatments have not yet been found.
The Mayo research team, led by Malcolm A. Leissring, Ph.D., a neuroscientist at Mayo Clinic in Florida, made the discovery by testing hundreds of enzymes for the ability to lower beta-amyloid levels. BACE2 was found to lower beta-amyloid more effectively than all other enzymes tested. The discovery is interesting because BACE2 is closely related to another enzyme, known as BACE1, involved in producing beta-amyloid.
“Despite their close similarity, the two enzymes have completely opposite effects on beta-amyloid — BACE1 giveth, while BACE2 taketh away,” Dr. Leissring says.
Beta-amyloid is a fragment of a larger protein, known as APP, and is produced by enzymes that cut APP at two places. BACE1 is the enzyme responsible for making the first cut that generates beta-amyloid. The research showed that BACE2 cuts beta-amyloid into smaller pieces, thereby destroying it, instead. Although other enzymes are known to break down beta-amyloid, BACE2 is particularly efficient at this function, the study found.
Previous work had shown that BACE2 can also lower beta-amyloid levels by a second mechanism: by cutting APP at a different spot from BACE1. BACE2 cuts in the middle of the beta-amyloid portion, which prevents beta-amyloid production.
“The fact that BACE2 can lower beta-amyloid by two distinct mechanisms makes this enzyme an especially attractive candidate for gene therapy to treat Alzheimer’s disease,” says first author Samer Abdul-Hay, Ph.D., a neuroscientist at Mayo Clinic in Florida.
The discovery suggests that impairments in BACE2 might increase the risk of Alzheimer’s disease. This is important because certain drugs in clinical use — for example, antiviral drugs used to treat human immunodeficiency virus (HIV) — work by inhibiting enzymes similar to BACE2.
Although BACE2 can lower beta-amyloid by two distinct mechanisms, only the newly discovered mechanism — beta-amyloid destruction — is likely relevant to the disease, the researchers note. This is because the second mechanism, which involves BACE2 cutting APP, does not occur in the brain. The researchers have obtained a grant from the National Institutes of Health to study whether blocking beta-amyloid destruction by BACE2 can increase the risk for Alzheimer’s disease in a mouse model of the disease.
(Source: newswise.com)
Researchers from ETH Zurich have quite literally created a “cell phone”: they have reprogrammed mammalian cells in such a way that they can “phone” each other via chemical signals.
Telephoning is a mutual exchange of information: A phones B and they both agree what B should do. Once this is done, Party B phones Party A to let him or her know. A no longer phones B. During this two-way communication, electrical signals are sent, and for their transmission suitable devices are necessary.
Based on this formula, a team of bioengineers headed by Martin Fussenegger and Jörg Stelling at ETH Zurich’s Department of Biosystems Science and Engineering in Basel has programmed mammalian cells in such a way that two cells can communicate via chemical signals. The scientists have thus incorporated a synthetic two-way communication system into mammalian cells for the first time that also responds to concentration differences in the signal molecules. The researchers used suitable signal molecules and constructed “devices” out of biological components that receive, process and respond accordingly to the signals. The devices consist of suitable genes and their products, proteins, which are linked to each other logically.
Vitamin D deficiency during pregnancy could hinder babies’ brain development, impeding their mental and motor skills, a new study suggests.
Researchers in Spain measured the level of vitamin D in the blood of almost 2,000 women in their first or second trimester of pregnancy and evaluated the mental and motor abilities of their babies at about 14 months of age. The investigators found that children of vitamin D-deficient mothers scored lower than those whose mothers had adequate levels of the sunshine vitamin.
"These differences in the mental and psychomotor development scores do not likely make any difference at the individual level, but might have an important impact at the population level," said study lead author Dr. Eva Morales, a medical epidemiologist in the Center for Research in Environmental Epidemiology in Barcelona.
Overall, lower scores in these tests could lead to lower IQs among children, Morales added. The study was published online Sept. 17 and in the October print issue of the journal Pediatrics.
A new study published in Social Cognitive and Affective Neuroscience by researchers at the Center for BrainHealth at UT Dallas and UT Southwestern found brain-based differences in how women with and without anorexia perceive themselves. The findings shed light on how brain pathways function in ill and fully recovered individuals who have had anorexia nervosa.
Small genetic change has heavy consequences
One small change to the DNA sequence can cause more weighty changes to the human body, according to a new study released today. The discovery comes thanks to a worldwide consortium of researchers that includes Professor and Chair of Quantitative Genetics at The University of Queensland (UQ), Peter Visscher, from the Queensland Brain Institute (QBI) and Diamantina Institute (DI) at UQ.
He and his team have found a single change in genetic sequence at the gene FTO had a significant effect on the variability of body mass index (BMI). BMI is a commonly used measure of obesity. It measures someone’s weight adjusted for his or her height.
Professor Visscher said that the genetic change, called a single nucleotide polymorphism (SNP), was the replacement of one nucleotide – the units that make up our DNA – with another. “They are the most abundant type of variation in the human genome,” he said. “SNPs occur normally throughout our DNA and most have no effect on our health, however, we’ve found one that does have a small but significant effect on variation in BMI.”
After analysing data from almost 170,000 people, he and his team established that those with a sequence variant in the FTO gene not only weighed more on average, but the measured weights varied more than in the group without the variant. The variability of BMI within the group with two copies of the variant was, in fact, 7 per cent larger than the group without the variant.
Professor Visscher said this equated to around half a kilogram difference in the standard deviation of weight. “So as a group, people with two copies of the weight increasing variant are a few kilograms heavier and vary more,” he said. Genetic differences in variability of specific traits have been seen in many plant and animal species but specific genes or mechanisms to explain the phenomenon had not been identified.
Professor Visscher’s study is the first to look systematically at genetic effects on variation of a complex trait in humans using a very large sample size. “The study is important because it demonstrates that genes can be found that affect trait variability. “This is a first step towards understanding how genes control variation,” Professor Visscher said.
This study is also the first to offer researchers an indirect method to measure genotype by environment interactions without having a measure of specific environmental factors. “If a gene interacts with specific environmental factors then this can be observed with our method,” Professor Visscher said.
“For example, if the effect of a gene on weight is smaller in people who physically exercise than in people who do not, then this will lead to less variation among people with two copies of the weight decreasing variant.
“In our study we did not measure specific environmental effects such as physical exercise so we can’t say for sure whether our results are due to a genotype-environment interaction.”
This is the second study Professor Visscher has published in the prestigious journal Nature this year. Earlier this year he identified that genetic differences also affect how intelligence changes across a lifetime. The work also suggested these changes in intelligence were largely influenced by environmental factors.
(Source: uq.edu.au)
![Adequate sleep helps weight loss
Adequate sleep is an important part of a weight loss plan and should be added to the recommended mix of diet and exercise, states a commentary in CMAJ (Canadian Medical Association Journal).
Although calorie restriction and increased physical activity are recommended for weight loss, there is significant evidence that inadequate sleep is contributing to obesity. Lack of sleep increases the stimulus to consume more food and increases appetite-regulating hormones.
"The solution [to weight loss] is not as simple as ‘eat less, move more, sleep more,’" write Drs. Jean-Phillippe Chaput, Children’s Hospital of Eastern Ontario Research Institute, Ottawa, Ontario and Angelo Tremblay, Laval University, Québec, Quebec. "However, an accumulating body of evidence suggests that sleeping habits should not be overlooked when prescribing a weight-reduction program to a patient with obesity. Sleep should be included as part of the lifestyle package that traditionally has focused on diet and physical activity."
The authors’ recently published research found that total sleep time and quality of sleep predicted the loss of fat in people enrolled in a weight loss program.
The Canadian Obesity Network has included adequate sleep in its new set of obesity management tools for physicians.](http://41.media.tumblr.com/tumblr_majgjbN8VU1rog5d1o1_500.jpg)
Adequate sleep helps weight loss
Adequate sleep is an important part of a weight loss plan and should be added to the recommended mix of diet and exercise, states a commentary in CMAJ (Canadian Medical Association Journal).
Although calorie restriction and increased physical activity are recommended for weight loss, there is significant evidence that inadequate sleep is contributing to obesity. Lack of sleep increases the stimulus to consume more food and increases appetite-regulating hormones.
"The solution [to weight loss] is not as simple as ‘eat less, move more, sleep more,’" write Drs. Jean-Phillippe Chaput, Children’s Hospital of Eastern Ontario Research Institute, Ottawa, Ontario and Angelo Tremblay, Laval University, Québec, Quebec. "However, an accumulating body of evidence suggests that sleeping habits should not be overlooked when prescribing a weight-reduction program to a patient with obesity. Sleep should be included as part of the lifestyle package that traditionally has focused on diet and physical activity."
The authors’ recently published research found that total sleep time and quality of sleep predicted the loss of fat in people enrolled in a weight loss program.
The Canadian Obesity Network has included adequate sleep in its new set of obesity management tools for physicians.
Women are better than men at recognizing living things and men are better than women at recognizing vehicles.
That is the unanticipated result of an analysis Vanderbilt psychologists performed on data from a series of visual recognition tasks collected in the process of developing a new standard test for expertise in object recognition.
“These results aren’t definitive, but they are consistent with the following story,” said Gauthier. “Everyone is born with a general ability to recognize objects and the capability to get really good at it. Nearly everyone becomes expert at recognizing faces, because of their importance for social interactions. Most people also develop expertise for recognizing other types of objects due to their jobs, hobbies or interests. Our culture influences which categories we become interested in, which explains the differences between men and women.”
The results were published online on Aug. 3 in the Vision Research journal in an article titled, “The Vanderbilt Expertise Test Reveals Domain-General and Domain-Specific Sex Effects in Object Recognition.”
A new light-based technique for measuring levels of the toxic protein that causes Huntington’s disease (HD) has been used to demonstrate that the protein builds up gradually in blood cells. Published in the Journal of Clinical Investigation, the findings shed light on how the protein causes damage in the brain, and could be useful for monitoring the progression of HD, or testing new drugs aimed at suppressing production of the harmful protein.
Memory vs. Math: Same brain areas show inverse responses to recall and arithmetic
Scientists have historically relied on neuroimaging – but not electrophysiological – data when studying the human default mode network (DMN), a group of brain regions with lower activity during externally-directed tasks and higher activity if tasks require internal focus. Recently, however, researchers at Stanford University School of Medicine recorded electrical activity directly from a core DMN component known as the posteromedial cortex (PMC) during both internally- and externally-directed waking states – specifically, autobiographical memory and arithmetic calculation, respectively. The data they recorded showed an inverse relationship – namely, the degree activation during memory retrieval predicted the degree of suppression during arithmetic calculation – which they say provides important anatomical and temporal details about DMN function at the neural population level.