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.
One of areas of genetic interest of autism is a region of chromosome 15. Only about 3% of people with autism have the mutation, but 80% of those with the mutation have autism. It is so important that people with duplications of this area have formed their own advocacy group called the Dup15 Alliance. I was honored to attend their family an scientific meeting and give a summary of what scientists have learned about autism through studying this chromosome, how kids with this mutation and autism are similar and different from those with autism but not the mutation, how the families are managing life threatening seizures, what the gene does, what the brains look like, and how mutations of this chromosome do in fact interact with the environment. Thank you to the scientists who study this area and the very brave, selfless and amazing parents who I talked to.
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.
On October 14th, the Autism BrainNet hosted it’s first webinar around how brain tissue findings affect people with autism. First, Shafali Jeste, MD, from UCLA explained what seizures were, how prevalent they were in people with autism, and what the risk factors for them were in ASD. Next, David Menassa from Oxford University described recent findings in brain tissue which showed how glia cells, or the cells of the brain that support neurons, are affected in ASD and how epilepsy affects these changes. The introduction of the webinar is missing but only for a few seconds. Thank you to Drs. Jeste and Menassa for participating in such a great informational event and for everyone that registered.
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!