The Director of the National Institute of Mental Health, Tom Insel, comments on relevant research advances periodically, and on Aug 24 he had this to say, “The strangest discovery of the summer may be the report of bone marrow transplants resolving the symptoms of autism…in mice. Paul Patterson and his colleagues at California Institute of Technology created an autism-like syndrome in mice by exposing them to immune challenges during mid-gestation.3 Once grown up, these prenatally exposed mice showed immune changes but also increased anxiety, decreased social behavior, and repetitive behaviors. A bone marrow transplant, which replaces the immune system, corrected both the immune response and the behavior. This finding, which was unexpected, is surprisingly similar to another recent paper reporting disappearance of the symptoms of Rett syndrome in mice following a bone marrow transplant.4 Both studies suggest that abnormalities of the immune system may underlie some of the symptoms of these neurodevelopmental disorders.” I’ll have to ask him about the the use of “strangest” here.
Another fun choice of adjectives: “But for me the most disorienting discovery of the summer came from the score of papers in July and August on the microbiome. In the same way that cognitive psychology has redefined how we think about our minds, the microbiome must now redefine how we think about our bodies. Actually the term “our bodies” is no longer accurate. Only 10 percent of our bodies’ genetic material checks out as human DNA: some 90 percent belongs to the trillions of microbes that live on and inside us. If all the cells in our bodies were to take a vote, human cells lose. The reports from the last month begin to map the biogeography of the human body, revealing that we are really a complex ecosystem with regional variation and completely unexpected individual variation in the microbes that make each of us a super-organism. How does this variation influence brain development? What does this variable ecosystem of our bodies mean for the individual differences in our minds? Will the microbiome help us to understand or treat mental disorders? All questions that we can begin to address in the fall.” I think he will be really disoriented when he sees our new paper, which is in review at the moment. Elaine Hsiao will be presenting these new findings on the role of the gut microbiota in the autism-like behaviors of our mouse model. This will be at the Society for Neuroscience meeting in New Orleans Oct. 13-17.