Posts tagged brain

Posts tagged brain
Intelligence Is in the Genes, but Where?
You can thank your parents for your smarts—or at least some of them. Psychologists have long known that intelligence, like most other traits, is partly genetic. But a new study led by psychological scientist Christopher Chabris of Union College reveals the surprising fact that most of the specific genes long thought to be linked to intelligence probably have no bearing on one’s IQ. And it may be some time before researchers can identify intelligence’s specific genetic roots.
Chabris and David Laibson, a Harvard economist, led an international team of researchers that analyzed a dozen genes using large data sets that included both intelligence testing and genetic data.
In nearly every case, the researchers found that intelligence could not be linked to the specific genes that were tested. The results are published online in Psychological Science, a journal of the Association for Psychological Science.
“In all of our tests we only found one gene that appeared to be associated with intelligence, and it was a very small effect. This does not mean intelligence does not have a genetic component. It means it’s a lot harder to find the particular genes, or the particular genetic variants, that influence the differences in intelligence,” said Chabris.
Parents should not worry that proposed changes to the medical criteria redefining a diagnosis of autism will leave their children excluded and deemed ineligible for psychiatric and medical care, says a team of researchers led by psychologists at Weill Cornell Medical College.
Their new study, published in the October 1 issue of the American Journal of Psychiatry, is the largest to date that has tried to unpack the differences between the diagnostic criteria for autism spectrum disorders in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) and the proposed revision in the fifth edition (DSM-5), which is expected to be published in May 2013. These manuals provide diagnostic criteria for people seeking mental-health-related medical services.
"I know that parents worry, but I don’t believe there is any substantial reason to fear that children who need to be diagnosed with autism spectrum disorders, and provided with vital services, will not be included in the new criteria in this updated manual," says the study’s senior investigator, Dr. Catherine Lord, director of the Center for Autism and the Developing Brain at NewYork-Presbyterian Hospital’s Westchester campus, along with its affiliated medical schools Weill Cornell Medical College and Columbia University College of Physicians and Surgeons.
At issue is whether DSM-5 will “capture” the same individuals diagnosed with different forms of autism by the DSM-IV. The DSM-5 proposal redefines autism as a single category — autism spectrum disorder (ASD) — whereas DSM-IV had multiple categories and included Autistic Disorder, Asperger’s Disorder, and Pervasive Developmental Disorder, Not Otherwise Specified (PDD-NOS).
Critics have particularly worried that among the excluded will be children now diagnosed with PPD-NOS and Asperger’s disorder. That isn’t the case, says Dr. Lord, who is also a DeWitt Wallace Senior Scholar at Weill Cornell and an attending psychologist at NewYork-Presbyterian Hospital. The study, the largest to date and arguably, the most rigorous, finds that when relying on parent report, 91 percent of the 4,453 children in the sample currently diagnosed with a DSM-IV autism spectrum disorder would be diagnosed with ASD using DSM-V.
Many of the remaining nine percent would likely be reincluded once a clinician can offer input, says Dr. Lord, who is also a member of the American Psychiatric Association’s DSM-5 Neurodevelopmental Disorders Work Group.
The study researchers also concluded that DSM-5 has higher specificity than DSM-IV—in their study, DSM-5 criteria resulted in fewer misclassifications.
(Source: weill.cornell.edu)
University of Miami researchers find that babies’ non-verbal communication skills can help predict outcomes in children at high risk of developing Autism
Approximately 19 percent of children with a sibling diagnosed with Autism Spectrum Disorder (ASD) will develop Autism due to shared genetic and environmental vulnerabilities, according to previous studies. For that reason, University of Miami (UM) psychologists are developing ways to predict the occurrence of ASD in high-risk children, early in life, in hopes that early intervention will lead to better outcomes in the future. Their findings are published in the journal Infancy.
The study is one of the first to show that measures of non-verbal communication in children, as young as eight months of age, predict autism symptoms that become evident by the third year of life. The results suggest that identifying children, who are having difficulties early enough, can enhance the effects of interventions.
The Obese Brain May Thwart Weight Loss
New research by Terry Davidson, director of American University’s Center for Behavioral Neuroscience, indicates that diets that lead to obesity—diets high in saturated fat and refined sugar—may cause changes to the brains of obese people that in turn may fuel overconsumption of those same foods and make weight loss more challenging.
“It is a vicious cycle that may explain why obesity is so difficult to overcome,” said Davidson, also a professor of psychology at AU.
Davidson recently published his research, “The Effects of a High-Energy Diet on Hippocampal-Dependent Discrimination Performance and Blood-Brain Barrier Integrity Differ for Diet-Induced Obese and Diet-Resistant Rats,” in the journal Physiology & Behavior.
Fluoxetine increases aggressive behavior, affects brain development among adolescent hamsters
Fluoxetine was the first drug approved by the FDA for major depressive disorder (MDD) in children and adolescents, and to this date, it remains one of only two selective serotonin reuptake inhibitors (SSRIs) registered for treatment of MDD in children and adolescents, despite reports that indicate this class of drugs is associated with side effects, such as agitation, hostility and aggression.
SSRIs have been amongst the most widely prescribed medications in psychiatry for over a decade. While there is a wealth of information regarding their effectiveness and safety in adults, considerably less data exists regarding whether they are safe for children.
A study published in Behavioral Neuroscience by Prof. Richard Melloni of Northeastern University shows that repeated administration of a low dose of fluoxetine to adolescent hamsters dramatically increased offensive aggression and altered the development of brain areas directly associated with controlling the aggressive response. “These data show clearly that repeated exposure to fluoxetine during adolescence directly stimulates aggressive responding and alters the normal development of two important brain systems, i.e., the serotonin and vasopressin neural systems, in a fashion consistent with the expression of the highly aggressive behavioral characteristics.”
For over a decade, Prof. Melloni and his team have researched the neural and behavioral consequences of illicit drugs and prescribed medications on the adolescent brain. Importantly, the data collected during the study indicates that clinically relevant doses of fluoxetine, when administered during adolescent development, can dramatically alter the wiring of brain circuits implicated in aggression control. “These data support the notion that interactions between adolescent fluoxetine and the developing vasopressin neural system might underlie fluoxetine-induced aggressive behavior and hint that serotonin, perhaps by acting on vasopressin neurons, may play a more permissive role in this response.”
(Image credit: Benjah-bmm27)
(Source: northeastern.edu)
Omega-3 Supplements May Slow A Biological Effect of Aging
Taking enough omega-3 fatty acid supplements to change the balance of oils in the diet could slow a key biological process linked to aging, new research suggests.
The study showed that most overweight but healthy middle-aged and older adults who took omega-3 supplements for four months altered a ratio of their fatty acid consumption in a way that helped preserve tiny segments of DNA in their white blood cells.
These segments, called telomeres, are known to shorten over time in many types of cells as a consequence of aging. In the study, lengthening of telomeres in immune system cells was more prevalent in people who substantially improved the ratio of omega-3s to other fatty acids in their diet.
Omega-3 supplementation also reduced oxidative stress, caused by excessive free radicals in the blood, by about 15 percent compared to effects seen in the placebo group.
“The telomere finding is provocative in that it suggests the possibility that a nutritional supplement might actually make a difference in aging,” said Jan Kiecolt-Glaser, professor of psychiatry and psychology at Ohio State and lead author of the study.
Homolog of mammalian neocortex found in bird brain
A seemingly unique part of the human and mammalian brain is the neocortex, a layered structure on the outer surface of the organ where most higher-order processing is thought to occur. But new research at the University of Chicago has found the cells similar to those of the mammalian neocortex in the brains of birds, sitting in a vastly different anatomical structure.
The work, published in Proceedings of the National Academy of Sciences, confirms a 50-year-old hypothesis about the identity of a mysterious structure in the bird brain that has provoked decades of scientific debate. The research also sheds new light on the evolution of the brain and opens up new animal models for studying the neocortex.
"If you want to study motor neurons or dopamine cells, which are biomedically important, you can study them in mammals, in chick embryos, in zebrafish. But for these neurons of the cerebral cortex, we could only do that in mammals before," said Clifton Ragsdale, PhD, associate professor of neurobiology at University of Chicago Biological Sciences and senior author of the study. "Now, we can take advantage of these other experimental systems to ask how they are specified, can they regenerate, and other questions."
Both the mammalian neocortex and a structure in the bird brain called the dorsal ventricular ridge (DVR) originate from an embryonic region called the telencephalon. But the two regions mature into very different shapes, with the neocortex made up of six distinct cortical layers while the DVR contains large clusters of neurons called nuclei.
Japanese Study Shows Cute Pics Of Puppies May Improve Concentration
Has your boss ever caught you looking at pictures of adorable kittens on the internet when you’re supposed to be working? If so, Japanese researchers may have provided you with the perfect excuse for putting off work and gawking at those cute little critters.
A new study by psychologists at Hiroshima University indicates that viewing pictures of kittens or puppies actually improved the ability of test subjects to concentrate and focus.
Previous research by American psychologists showed that seeing cute animal pictures could improve fine motor skills when playing a game like the classic Milton Bradley board game Operation. This new study, published in the latest edition of PLOS ONE, expands on those findings by demonstrating that the improved focus applies to mental tasks as well as physical ones.
New research in The FASEB Journal suggests that serum from animals such as camels, llamas, and alpacas could enhance brain imaging and help drugs pass through the blood-brain barrier
President Obama’s national plan to fight Alzheimer’s disease just got a lift thanks to a team of international researchers whose recent discovery may lead to enhanced imaging of and improved drug delivery to the brain. A research report appearing in The FASEB Journal, describes an entirely new class of antibody discovered in camelids (camels, dromedaries, llamas, and alpacas) that is able to cross the blood-brain barrier, diffuse into brain tissue, and reach specific targets. Having such antibodies, which are naturally available, may be part of a “game changer” in the outcomes for people with brain diseases that are poorly diagnosed and treated, at best, using today’s tools.
"This basic biological investigation opens new pathways toward innovative therapeutic solutions for intractable diseases such as Alzheimer’s disease or brain tumors," said Pierre Lafaye, Ph.D., a researcher involved in the work from the Institut Pasteur, PF: Production de Protéines Recombinantes et d’Anticorps –Proteopole in Paris, France. "The importance of this study is the hope that this novel approach may be a useful tool in crossing the blood brain barrier for diagnostic and therapeutic purposes," added Babbette Weksler, MD, Professor of Medicine, Weill Cornell Medical College, New York, NY, another author of the study and editorial board member of The FASEB Journal.
Penn Researchers Connect Baboon Personalities to Social Success and Health Benefits
Whether human or baboon, it helps to have friends. For both species, studies have shown that robust social networks lead to better health and longer lives. Now, a team of University of Pennsylvania researchers has helped show that baboon personality plays a role in these outcomes, and, like people, some baboons’ personalities are better suited to making and keeping friends than others.
The research was conducted by psychology professor Robert Seyfarth and biology professor Dorothy Cheney, both of Penn’s School of Arts and Sciences. They collaborated with the Arizona State University’s Joan Silk.
Their work was published in the Proceedings of the National Academy of Sciences