“As this has been modeled using a variety of different animal’s systems, it’s become clear that pathogenesis is not specific to the agent, but rather to the host immunoresponse,” Dr. Lipkin said. “And as you begin to understand more about the genetics of immunity, you can understand how these things might funnel through a common pathway to result in various sorts of common pathways for damage.”
One way in which this can be modeled, without considering a specific virus or bacterium, is to directly stimulate the immune response, which Dr. Lipkin said has been done using a double-stranded RNA molecule as a viral mimic that looks like a replicating virus and introducing this into animal models at different stages of gestation.
“Depending on when you’re exposed during the development of the central nervous system, you may have one manifestation or another,” he said. One model, for example, may lead to the expression of withdrawal behavior that looks like autism, while another exposed to the same agent at a different stage might look like attention deficit hyperactivity disorder.