Posts tagged autism
Articles and news from the latest research reports.
Scripps Florida Scientists Uncover Secrets of How Intellect and Behavior Emerge During Childhood
Scientists from the Florida campus of The Scripps Research Institute (TSRI) have shown that a single protein plays an oversized role in intellectual and behavioral development. The scientists found that mutations in a single gene, which is known to cause intellectual disability and increase the risk of developing autism spectrum disorder, severely disrupts the organization of developing brain circuits during early childhood. This study helps explain how genetic mutations can cause profound cognitive and behavioral problems.
The study was published in the November 9, 2012, issue of the journal Cell.
The genetic mutations that cause developmental disorders, such as intellectual disability and autism spectrum disorder, commonly affect synapses, the junctions between two nerve cells that are part of the brain’s complex electro-chemical signaling system. A substantial percentage of children with severe intellectual and behavioral impairments are believed to harbor single mutations in critical neurodevelopmental genes. Until this study, however, it was unclear precisely how pathogenic genetic mutations and synapse function were related to the failure to develop normal intellect.
“In this study, we did something no one else had done before,” said Gavin Rumbaugh, a TSRI associate professor who led the new research. “Using an animal model, we looked at a mutation known to cause intellectual disability and showed for the first time a causative link between abnormal synapse maturation during brain development and life-long cognitive disruptions commonly seen in adults with a neurodevelopmental disorder.”
Research by scientists from the Centre for Brain Research at the University of Auckland has uncovered new information about the mechanisms underlying autism spectrum disorders (ASDs), to be published in the next issue of the prestigious Journal of Neuroscience.
Principal investigator, Dr Johanna Montgomery, says the findings are highly significant: “We’re moving beyond simply what happens in ASDs and starting to understand how it happens.”
The behavioural manifestations of ASDs are well documented and include impaired communication and socialisation, learning difficulties, and repetitive or stereotyped behaviours. These behavioural characteristics are in turn associated with a wide range of gene mutations. Many of these mutated genes are responsible for the production of specific proteins in the neurons of the brain.
Dr Montgomery and her team took a close look at parts of these neurons – the synapses, which are the structures that enable brain cells to communicate with each other. This cell to cell communication is vital for a healthy brain, and underlies how we learn, remember, move and sense.
In a complex cascade of chemical and electrical signalling, information is transmitted from one neuron to another at the synapses. This process is mediated by several families of protein, some of which form the bedrock of the synapse on the ‘listening’ side. Dr Montgomery’s team chose to investigate one of these proteins, known as Shank3, because it has been identified as vital to the communication process between two neurons, and because it is known to be mutated in ASDs.
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.
Brain imaging alone cannot diagnose autism
In a column appearing in the current issue of the journal Nature, McLean Hospital biostatistician Nicholas Lange, ScD, cautions against heralding the use of brain imaging scans to diagnose autism and urges greater focus on conducting large, long-term multicenter studies to identify the biological basis of the disorder.
"Several studies in the past two years have claimed that brain scans can diagnose autism, but this assertion is deeply flawed," said Lange, an associate professor of Psychiatry and Biostatistics at Harvard Medical School. "To diagnose autism reliably, we need to better understand what goes awry in people with the disorder. Until its solid biological basis is found, any attempt to use brain imaging to diagnose autism will be futile."
While cautioning against current use of brain imaging as a diagnostic tool, he is a strong proponent of using this technology to help scientists better understand autism. Through the use of various brain imaging techniques, including functional magnetic resonance imaging (MRI), positron emission tomography (PET), and volumetric MRI, Lange points out that researchers have made important discoveries related to early brain enlargement in the disorder, how those with autism focus during social interaction and the role of serotonin in someone with autism.
"Brain scans have led to these extremely valuable advances, and, with each discovery, we are getting closer to solving the autism pathology puzzle," said Lange. "What individuals with autism and their parents urgently need is for us to carry out large-scale studies that lead us to find reliable, sensitive and specific biological markers of autism with high predictive value that allow clinicians to identify interventions that will improve the lives of people with the disorder."
Autism and autism spectrum disorder (ASD) are terms regularly used to describe a group of complex disorders of brain development. This spectrum characterized, in varying degrees, by difficulties in social interaction, verbal and nonverbal communication, and repetitive behaviors, whose criteria have been revised in the newly proposed Diagnostic and Statistical Manual of Mental Disorders (DSM-5). The prevalence of ASD in the United States has increased 78 percent in the last decade, with the Centers for Disease Control estimating that one in 88 children has ASD.
(Source: eurekalert.org)
Distinct developmental patterns identified in children with autism during their first three years
In the largest prospective study to date of children with early and later manifestation of autism spectrum disorders (ASD) compared to children without ASD, researchers found two distinct patterns of language, social and motor development in the children with ASD. Published in the journal Child Development, the study found that early in development, children who display early signs of ASD show greater initial delay across multiple aspects of development compared to children whose ASD symptoms emerge later. However at 36 months of age, the early differences between these groups are no longer obvious. By the third birthday, the level of impairment between these symptom onset groups of children with ASD is comparable. Additionally, researchers uncovered a preclinical phase of ASD in which the signs of delay are not easily detected with existing clinical tests.
Previous research by Kennedy Krieger Institute researchers found that approximately half of all children with ASD can be diagnosed around the first birthday, while the remaining half do not show diagnostic indicators until later. The current study builds upon these findings by further evaluating motor and language development in a wider age span of children diagnosed with ASD (6 to 36 months), and examining how development unfolds differently in each group.
“Regardless of diagnosis, the development of children with and without ASD appears similar at six months of age on clinical tests,” says Dr. Rebecca Landa, lead author and director of Kennedy Krieger’s Center for Autism and Related Disorders. “However, for those children who went on to develop autism, the earliest signs of atypical development were non-specific to autism, such as general communication or motor delay.”
Early Intervention Improves Social Skills and Brain Activity in Preschoolers with Autism
The Early Start Denver Model (ESDM), a comprehensive behavioral early intervention program that is appropriate for children with autism spectrum disorder (ASD) as young as 12 months, has been found to be effective in improving social skills and brain responses to social cues in a randomized controlled study published online today in the Journal of the American Academy of Child & Adolescent Psychiatry.
“So much of a toddler’s learning involves social interaction, and early intervention that promotes attention to people and social cues may pay dividends in promoting the normal development of the brain and behavior,” said Geraldine Dawson, Ph.D., Autism Speaks chief science officer and the study’s lead author. This is the first controlled study of an intensive early intervention that demonstrates both improvement of social skills and brain responses to social stimuli resulting from intensive early intervention. Given that the American Academy of Pediatrics recommends that all 18- and 24-month-old children be screened for autism, “it is vital that we have effective therapies available for young children as soon as they are diagnosed,” continued Dr. Dawson.
“This may be the first demonstration that a behavioral intervention for autism is associated with changes in brain function as well as positive changes in behavior,” said Thomas R. Insel, M.D., director of the National Institute of Mental Health. “By studying changes in the neural response to faces, Dawson and her colleagues have identified a new target and a potential biomarker that can guide treatment development.”
ESDM, which combines applied behavioral analysis (ABA) teaching methods with developmental ‘relationship-based’ approaches, was previously demonstrated to achieve significant gains in cognitive, language and daily living skills compared to children with ASD who received commonly available community interventions. On average, the preschoolers receiving ESDM for two years improved 17.5 standard score points compared to 7.0 points in the community intervention comparison group.
Are Schizophrenia and Autism Close Relations?
TAU researcher discovers that family history of schizophrenia is a risk factor for autism
Autism Spectrum Disorders (ASD), a category that includes autism, Asperger Syndrome, and Pervasive Developmental Disorder, are characterized by difficulty with social interaction and communication, or repetitive behaviors. The U.S. Centers for Disease Control and Management says that one in 88 children in the US is somewhere on the Autism spectrum — an alarming ten-fold increase in the last four decades.
New research by Dr. Mark Weiser of Tel Aviv University’s Sackler Faculty of Medicine and the Sheba Medical Center has revealed that ASD appears share a root cause with other mental illnesses, including schizophrenia and bipolar disorder. At first glance, schizophrenia and autism may look like completely different illnesses, he says. But closer inspection reveals many common traits, including social and cognitive dysfunction and a decreased ability to lead normal lives and function in the real world.
Studying extensive databases in Israel and Sweden, the researchers discovered that the two illnesses had a genetic link, representing a heightened risk within families. They found that people who have a schizophrenic sibling are 12 times more likely to have autism than those with no schizophrenia in the family. The presence of bipolar disorder in a sibling showed a similar pattern of association, but to a lesser degree.
A scientific leap forward, this study sheds new light on the genetics of these disorders. The results will help scientists better understand the genetics of mental illness, says Dr. Weiser, and may prove to be a fruitful direction for future research. The findings have been published in the Archives of General Psychiatry.
All in the family
Researchers used three data sets, one in Israel and two in Sweden, to determine the familial connection between schizophrenia and autism. The Israeli database alone, used under the auspices of the ethics committees of both the Sheba Medical Center and the Israeli Defense Forces, included anonymous information about more than a million soldiers, including patients with schizophrenia and ASD.
"We found the same results in all three data sets," he says, noting that the ability to replicate the findings across these extensive databases is what makes this study so significant.Understanding this genetic connection could be a missing link, Dr. Weiser says, and provides a fresh direction for study. The researchers are now taking this research in a clinical direction. For now, though, the findings shouldn’t influence the way that doctors treat patients with either illness, he adds.
(Source: aftau.org)
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.
Could Stem Cells Treat Autism? Newly Approved Study May Tell
Autism researchers have been given the go-ahead by the U.S. Food and Drug Administration to launch a small study in children with autism that evaluates whether a child’s own umbilical cord blood may be an effective treatment.
Thirty children with the disorder, aged 2 to 7, will receive injections of their own stem cells from umbilical cord blood banked by their parents after their births. All of the cord blood comes from the Cord Blood Registry, the world’s largest stem cell bank.
Scientists at Sutter Neuroscience Institute, in Sacramento, Calif., said the placebo-controlled study will evaluate whether the stem cell therapy helps improve language and behavior in the youngsters.
There is anecdotal evidence that stem cell infusions may have a benefit in other conditions such as cerebral palsy, said lead study investigator Dr. Michael Chez, director of pediatric neurology at the institute.
"We’re hoping we’ll see in the autism population a group of patients that also responds," Chez said. Other autism and stem cell research is going on abroad, but this study is the first to use a child’s own cord blood stem cells.
Chez said the study will involve only patients whose autism is not linked to a genetic syndrome or brain injury, and all of the children will eventually receive the stem cells.
Drug Reverses Abnormal Brain Function in Rett Syndrome Mice
A promising study out today in the prestigious Journal of Neuroscience showed that in a mouse model of Rett syndrome, researchers were able to reverse abnormalities in brain activity and improve neurological function by treating the animals with an FDA-approved anesthesia drug, ketamine. Rett syndrome is among the most severe autism-related disorders, affecting about one in 10,000 female births per year, with no effective treatments available.
“These studies provide new evidence that drug treatment can reverse abnormalities in brain function in Rett syndrome mice,” says David Katz, PhD, professor of neurosciences, Case Western Reserve University School of Medicine and senior author of the study. “They also provide new leads as to what kinds of drugs might be effective in individuals with Rett syndrome.”
Neuroscientists at Case Western Reserve University School of Medicine were able to successfully map differences in the brain activity of normal mice and those with a genetic mutation that mirrors the cause of Rett syndrome in humans. They found that – compared to normal mice – Rett syndrome mice showed regions of abnormally low activity in the front of the brain (forebrain) and regions of abnormally high activity in the back of the brain (brainstem). Importantly, they found that the regions of low activity overlap with regions of the brain that are also under-active in humans with classic autism. This indicates there may be common mechanisms underlying abnormal behaviors in the two diseases.
The identification of these brain regions provided clues into specific areas to target for treatment. Based on previously published findings that ketamine activated neurons in the forebrain, the researchers gave the drug to the Rett syndrome mice and found it increased levels of brain activity in those regions and improved neurological function. Importantly, the drug was effective at a low dose that did not produce anesthesia.