In a striking new finding, researchers at the UC Davis MIND Institute found that typically-developing children gain more neurons in a region of the brain that governs social and emotional behavior, the amygdala, as they become adults. This phenomenon does not happen in people with autism spectrum disorder (ASD). Instead, children with ASD have too many neurons early on and then appear to lose those neurons as they become adults. The findings were published today in the journal Proceedings of the National Academy of Sciences (PNAS).
The amygdala is a small almond-shaped group of 13 regions (nuclei) that work as a danger detector in the brain to regulate anxiety and social interactions. Amygdala dysfunction has been linked to many psychiatric and neurodevelopmental disorders, including ASD, schizophrenia, bipolar disorder and depression.
“The amygdala is a unique brain structure in that it grows dramatically during adolescence, longer than other brain regions, as we become more socially and emotionally mature,” said Cynthia Schumann, associate professor in the Department of Psychiatry and Behavioral Sciences at the UC Davis MIND Institute and senior author of the paper. “Any deviation from this normal path of development can profoundly influence human behavior.” To understand what cellular factors underlie amygdala development, the team studied 52 postmortem human brains, both neurotypical and ASD, ranging from 2 to 48 years of age.
Full story at Science Daily
Columbia scientists have identified a gene that allows neurons that release serotonin — a neurotransmitter that regulates mood and emotions — to evenly spread their branches throughout the brain. Without this gene, these neuronal branches become entangled, leading to haphazard distribution of serotonin, and signs of depression in mice. These observations shed light on how precise neuronal wiring is critical to overall brain health, while also revealing a promising new area of focus for studying psychiatric disorders associated with serotonin imbalance — such as depression, bipolar disorder, schizophrenia and autism.
The findings were published in Science.
“By pinpointing the genes that guide the organization of neurons, we can draw a line between changes to those genes, and the cellular, circuitry and behavioral deficiencies that can occur as a result,” said Tom Maniatis, PhD, a principal investigator at Columbia’s Mortimer B. Zuckerman Mind Brain Behavior Institute, the Isidore S. Edelman Professor and Chair of department of Biochemistry & Molecular Biophysics at Columbia University Medical Center and the studys’ senior author.
Full story of faulty wiring leads to depression like behavior at Science Daily
A new method devised by a Drexel University professor to diagnose children on the spectrum for anxiety symptoms — which tend to be masked by symptoms of autism — was shown to be effective in a recent study.
“Anxiety is considered an internalizing symptom, in that it is mostly felt by the person inside their bodies and minds and is not always obvious to others,” said Connor Kerns, PhD, an assistant research professor in the A.J. Drexel Autism Institute of Drexel University’s Dornsife School of Public Health. “For example, a child may avoid a social situation because they are not socially motivated — a symptom of autism spectrum disorder — or because they are afraid of being socially rejected — a symptom of anxiety.”
Full story of anxiety measure for children with autism at Science Daily
A well-established screening tool used to assess children for attention-deficit hyperactivity disorder (ADHD) may be less accurate when a child has an autism spectrum disorder (ASD). Pediatric researchers report that children with ASD may mistakenly be diagnosed with ADHD because they have autism-related social impairments rather than problems with attention. This is important for understanding what are the right services and treatments for a child.
The study team, including one of the psychologists who developed the ADHD screening tool, concludes that the tool needs to be refined to better identify the correct disorder, and that clinicians should supplement the screening tool with careful clinical interviews.
Full story of autism over-diagnosed with ADHD at Science Daily
A new study published in the online journal, Public Library of Science One (PLOS One) found that Vitamin B12 levels in the brain are significantly decreased in the elderly and are much lower in individuals with autism or schizophrenia, as compared to their peers at similar ages. For example, children with autism under the age of 10 were found to have three times lower brain B12 levels, which is similar to levels for generally healthy adults in their 50s, indicating a premature decrease.
The international research team led by Richard Deth, Ph.D., professor of pharmacology at Nova Southeastern University’s (NSU) College of Pharmacy, analyzed tissue from otherwise healthy deceased donors along with tissue from donors who had autism or schizophrenia to make the comparisons.
“These are particularly significant findings because the differences we found in brain B12 with aging, autism and schizophrenia are not seen in the blood, which is where B12 levels are usually measured.” said Dr. Deth. “The large deficits of brain B12 from individuals with autism and schizophrenia could help explain why patients suffering from these disorders experience neurological and neuropsychiatric symptoms.”
Full story of vitamin B12 decreasing in brain with age at Science Daily
A lot of research has shown that poor regulation of the serotonin system, caused by certain genetic variations, can increase the risk of developing psychiatric illnesses such as autism, depression, or anxiety disorders. Furthermore, genetic variations in the components of the serotonin system can interact with stress experienced during the fetal stages and/or early childhood, which can also increase the risk of developing psychiatric problems later on.
In order to better understand serotonin’s influence in the developing brain, Alexandre Dayer’s team in the Psychiatry and Fundamental Neuroscience Departments of UNIGE’s Faculty of medicine examined a particular receptor for this neurotransmitter, and its role in the formation of brain circuits. The researchers were able to show that this receptor, which is expressed in inhibitory interneurons (cells that regulate excitement in order to avoid potentially pathological cerebral over activity), was indispensable in order for neurons to find their correct location in the developing cortex.
Full story on serotonin’s role in brain circuits at Science Daily
Developing effective, real-world-ready approaches to providing early diagnosis, treatment, and supportive services for people with autism spectrum disorder (ASD) is the goal of 12 research grants awarded by the National Institute of Mental Health (NIMH). These grants are part of a broad research effort to provide models for the delivery of needed services to children, youth, and adults with ASD, across different communities and care settings, appropriate to each age and individual. NIMH is part of the National Institutes of Health (NIH).
While research has yielded much on understanding the biology of autism, access to effective treatment and services tailored to life stages remains a challenge for people with ASD and their families. In 2013, the Interagency Autism Coordinating Committee, a U.S. Department of Health and Human Services federal advisory group, developed an updated Strategic Plan for Autism Spectrum Disorder Research which identified access to services as a central concern of individuals and families affected by ASD. To foster research on these issues, NIMH solicited applications to study models for ASD service delivery in early childhood, during the transition out of high school, and in adulthood.
Full story of NIH projects at NIMH
Children and adolescents with autism have a surplus of synapses in the brain, and this excess is due to a slowdown in a normal brain “pruning” process during development, according to a study by neuroscientists at Columbia University Medical Center (CUMC). Because synapses are the points where neurons connect and communicate with each other, the excessive synapses may have profound effects on how the brain functions. The study was published in the August 21 online issue of the journal Neuron.
A drug that restores normal synaptic pruning can improve autistic-like behaviors in mice, the researchers found, even when the drug is given after the behaviors have appeared.
“This is an important finding that could lead to a novel and much-needed therapeutic strategy for autism,” said Jeffrey Lieberman, MD, Lawrence C. Kolb Professor and Chair of Psychiatry at CUMC and director of New York State Psychiatric Institute, who was not involved in the study.
Full story of synapses in children with autism at Science Daily