Shedding Light on the Secrets of Autism

Despite the fact that autism is more prevalent today than ever, its causes are still unknown – though research indicates that there are likely a number of contributing factors: environmental, genetic, neurological, biological. And while Weizmann Institute scientists have made significant contributions to the understanding of autism, developing means of diagnosis, and creating potential treatments, much remains to be done – which is why their research continues at a rapid pace and approaches the condition from multiple angles.

April is National Autism Awareness Month. To help increase knowledge and mindfulness of this common, complex condition, we’d like to share three recent major advances – each on a different aspect of autism – from the labs of the Weizmann Institute of Science. 

  • Scientists have proven that a common virus, if contracted during pregnancy, can lead to neurodevelopmental disorders, and even that the stage of pregnancy makes a difference; e.g., infection early in the pregnancy is more likely to result in autism, while later-stage infection more often leads to schizophrenia. But why? How?

    Renowned Weizmann neuroimmunologists Profs. Michal Schwartz and Ido Amit have provided a potential explanation for this increased risk on the cellular and the mechanistic molecular levels. Because fetal immune system development is interrupted by the virus, the scientists showed, the lack of coordination with brain development contributes to the increased risk of neurodevelopmental disorders like autism. 

    In addition to paving the way for studying the effects of other viruses on the mother’s immune system and on her offspring’s brain development, Profs. Schwarz and Amit’s findings can advance the study of neurodevelopmental disorders such as autism, and their connection to the immune system.

  • Dr. Ofer Yizhar helped pioneer a young, truly transformative field of neuroscience: optogenetics. The technique lets researchers use light to very precisely control neural activity – in fact, they are able to manipulate single neurons and measure the effects of those manipulations in real time, in a living, active animal, with an extraordinary degree of accuracy. This has been particularly useful in studying brain functions such as learning, memory, and social behavior, and how these might be altered in autism.

    In collaboration with Weizmann colleagues who were knowledgeable about the genetics of psychiatric disease, Dr. Yizhar developed a strain of “autistic” mice. Working with these animals, he devised a system that allowed him to activate individual neurons to see their in-the-moment effect on the mouse’s behavior.

    One of his most remarkable discoveries was that by activating or deactivating certain neurons, autistic behaviors could actually be switched on or off – effectively reversing autistic behavior. Turn the neuron off, the mouse behaves in an autistic manner. Turn it on, and it behaves normally again.

    Dr. Yizhar’s ongoing investigations include using optogenetics to discover how autism spectrum disorders develop in the brain, and which neural mechanisms are behind the behavioral impairments seen in these disorders.

  • One of the hallmarks of autism spectrum disorders is difficulty with social situations. While this is true for everyone – after all, meeting new people and being in never-before-experienced ​settings can be stressful – it​ is often more challenging to autistic persons. But why, and how, is this such a common autistic trait?

    Recent research in the lab of Prof. Alon Chen indicates that a molecule involved in regulating stress in the brain may help determine our willingness to leave the safety of our social group and strike up new relationships.

    The stress molecule appears to act as a “social switch”: mice with high levels of it were much more outgoing and eager to make new friends; when the molecule was blocked, Prof. Chen found, mice preferred the comfort of being with their family and old friends. Thus, disruptions in this mechanism might be responsible for difficulties with social coping in people affected by disorders such as social anxiety and autism. Perhaps, in the future, altering the level of this stress molecule could help people who are made profoundly uncomfortable by social situations.

Switching autistic behaviors on and off with optogenetics. Soothing the social discomfort of those on the autism spectrum. Investigating a cause of autism and a potential way to stop it. These are just some of the ways in which Weizmann Institute scientists are analyzing this common, confounding neuropsychological disorder – during Autism Awareness Month, and every month.