Gamma waves are brainwave activity at a certain speed and have been linked to consciousness and seem to help coordinate activity in different parts of the brain. They have also been associated with processing of information, including sensory information. This week, researchers at Oxford University led by Dr. David Menassa explore gamma waves in the brains of autistic adults who perform better on a visual processing task than those without a diagnosis. Gamma waves are controlled by the coordinated activity of neurons in the brain, which are regulated by inhibitory interneurons which make sure excitatory neurons aren’t taking over. In a study using brain tissue of people with autism, it was found by another study at Oxford that there are fewer of these inhibitory interneurons to control this activity. Dr. David Menassa provides his own interpretation of the data on this week’s podcast.
In order to ensure that researchers have enough brain tissue to understand autism spectrum disorders, the education and outreach campaign is being expanded past families to doctors and professionals that have access to tissue. One of these groups is neuropathologists. At their annual meeting this past week in Los Angeles, and entire afternoon was spent dedicated to autism and the features of autism in the brain. A summary of the presentations is included in this podcast. Speakers emphasized that the way the brain works in childhood is not the same way it works in adulthood, and a study out of UCSD showed that the genes that are affected in children with autism are different than those in adults with autism. The mechanisms of genes controlling the developing brain vs. those which affect ongoing maintenance are different. This calls to make sure scientists understand all ages of people with autism, because as the brain changes, so do the needs of people with ASD.
On May 4th, Dr. Janine LaSalle from UC Davis and (the soon to be Dr.) Keith Dunaway presented on recent research investigating the role of environmental factors in individuals with Dup15 Syndrome. Individuals with a mutation on chromosome 15 are often diagnosed with autism and previously it had been assumed that these individuals were destined to have a diagnosis due to their genetics. Dr. LaSalle shows that many of the genes in a critical region of chromosome 15 are tied to turning genes on and off via a process called methylation. Environmental chemicals or other exposures may also work on these genes to turn on or off gene expression epigenetically. The first half of the webinar reviews crucial ideas in gene x environment interactions and epigenetics, the second half describes experiments using brain tissue of those with Dup15 Syndrome and autism, as well as cell lines, to understand the role of PCBs in gene expression.
On Thursday, March 30th the Autism Science Foundation held their 4th Annual Day of Learning in NYC. If you were not able to attend and can’t wait for the videos of the talks, this week’s podcast attempts to summarize what was presented.
A list of the talks are:
- Autism Research: Where Are We Now? – Dr. Wendy Chung (Simons Foundation)
- Housing Options for Adults with Autism – Amy Lutz (EASI Foundation)
- Improving Communication Between Parents of Children with Autism and Teachers – Dr. David Mandell (University of Pennsylvania)
- Developing Clinical Biomarkers – Dr. James McPartland – (Yale University)
- Understanding Modifiable Autism Risk Factors – Dr. Craig Newschaffer (Drexel University)
- Helping People with Autism Develop Practical Skills – Dr. Celine Saulnier (Emory University)
- New Technologies to Improve Autism Diagnosis – Dr. Robert Schultz (Children’s Hospital of Philadelphia)
- Understanding the Female Protective Effect – Dr. Donna Werling (University of California, San Francisco)
David Mandell’s presentation on parent/teacher communication was based, in part, on this publication: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4676744/
Last month, UC Davis researcher Cyndi Schumann used resources for the Autism BrainNet to look at what causes differences in the rates of diagnosis between males and females. Consistent with other studies on this topic, males and females don’t show differences in the rates of autism genes, but rather in the way that the brain controls other genes that code for things like neuroinflammation and development. Clearly more studies are necessary but it is consistent with the Female Protective Effect in autism. The full text can be found here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5294827/
And also, there was a study on genital herpes and autism that CNN got totally wrong.
With hundreds of genes, thousands of environmental factors, and now sex being variables in determining risk for autism, where should science start? Over the decades researchers have been able to start narrowing down the combinations based on specific behaviors of interest, genes, and mechanisms which may narrow down which gene, which environmental factor and which sex. Dr. Sara Schaafsma and Dr. Donald Pfaff from Rockefeller University combined the three, and found that epigenetic changes in an autism risk gene called contact in associated protein like 2 contributed to elevation of risk for autism behaviors following maternal infection. In other words, being male and having the mutation produced small changes, increased by the environmental factor. In another separate study, Dr. Keith Dunaway and Dr. Janine LaSalle at UC Davis used brain tissue to look at a rare variant for autism on chromosome 15. Typically, mutations of this area of the genome are thought to cause autism. However, the effects of these mutations are also increased when environmental factors are present, leading to more de novo mutations. These are all examples of scientific breakthroughs that are helping better understand what causes autism. Even when it looks like one thing, it’s multiple things.
The year 2016 was eventful for many reasons. In this 20 minute podcast, we review some of the scientific discoveries that highlighted findings in causes, understanding, and treating ASD. Featured more this year is studies on the sibling of individuals with ASD, so we are calling 2016 “The Year of the Sibling” This review includes genetics, gene x environment interactions, diagnosis, the broader autism phenotype, and early interventions and the role of parent-delivered interventions in long term outcome. It also highlights the important role of studying brain tissue from individuals with autism to better understand people with autism across the lifespan, including those with known causes and unknown causes of ASD. We hope you find it informative – please send comments to firstname.lastname@example.org
On December 13, 2016, Dr. Matthew Anderson from Beth Isreal Deaconess Medical Center presented a 45 minute webinar on recent findings in autism thanks to studying the brains of people with autism. It covers genetics, neuropathology and immunology. It’s a great chance to hear a quick recap of findings from an Autism BrainNet node director. Please click above to watch the 45 minute presentation and questions from the audience. Most importantly, anyone can be a part of this important research by registering to learn more about the Autism BrainNet at www.takesbrains.org.
This week I am in Minneapolis at an incredibly important meeting of Medical Examiners to pitch them the importance of collecting brain tissue for Autism BrainNet. While I was here I noticed a new study on the blogs that is important for families to hear about. It focused on a known environmental exposure in established genetic groups. The authors of the study, led by Dr. Sara Webb at University of Washington, showed that an environmental exposure can modify symptoms in genetically susceptible narrow subgroups. This is the sort of research that will better describe how environmental exposures are affecting autism risk. Thank you to Dr. Sara Webb for your perspectives and interpretation of the data!