Researchers are claiming that the immune system affects and even controls social behavior in certain creatures, such as mice, which can have profound implications for humans with autism-spectrum disorders and schizophrenia.
This work was done in collaboration with researchers at the University of Virginia. Jonathan Kipnis, PhD, chair of neuroscience at the UVA School of Medicine showed that blocking IFN-γ in mice made mouse brains become hyperactive and caused atypical social behavior. Restoring of IFN-γ-signaling in the brain normalized brain activity and social behavior. “The brain and the adaptive immune system were thought to be isolated from each other, and any immune activity in the brain was perceived as a sign of pathology. And now, not only are we showing that they are closely interacting, but some of our behavior traits might have evolved because of our immune response to pathogens,” explained Dr. Kipnis.
Researchers highlighted a specific immune molecule known as interferon gamma, is activated in various creatures when they want to be social. When this molecule was genetically blocked in mice, their brains become hyperactive, specifically preventing the areas of the brain that govern social interaction. The scientists found the creatures were without access to the molecule interacted less other mice in their environment, despite the fact that mice are usually incredibly social creatures. Reintroducing interferon gamma back into the immune system calmed down the hyperactivity, that restored typical social behaviors.
The researchers note that a malfunctioning immune system may be responsible for “social deficits in numerous neurological and psychiatric disorders.” But exactly what this might mean for autism and other specific conditions requires further investigation
Additionally, the researchers prescribed a possible evolutionary cause for this occurrence: the relationship with people and pathogens, and the benefits of being social for a species to survive. When we interacted with others, it’s suggested that our immune systems would respond so that we could protect ourselves from any diseases that could be spread.
[Source – University of Virginia]