New Study: Increased Immune Activation During Pregnancy May Lead To Higher Risk of Autism and Schizophrenia
By: Erin Thomas
A new study by researchers at the UC Davis Center for Neuroscience and Department of Neurology found that viral infection during pregnancy may cause a higher chance of autism onset as well as schizophrenia. This is the first evidence that levels of major histocompatibility complex class I molecules (MHC1), cells involved in regulating immunity, are altered on the surface of neurons in an offspring’s brain if the mother’s immune system is activated. The study showed that MHC1 levels are doubled on the surface of neurons in the newborn offspring of mothers whose immune systems are activated. This suggests that MHC1 levels are very responsive to a peripheral immune response in the mother (Elmer, 2013). This is significant because maternal immune activation is a risk factor for Autism Spectrum Disorders and schizophrenia in humans. Mouse models have shown that offspring of mothers with immune activation show symptoms of both ASD and schizophrenia. This study demonstrated that maternal immune activation causes MHC1 signaling to limit the capability of neurons to form synapses, which are connections between neurons. When MHC1 levels in the newborns were made to return to normal, synaptic densities also returned to normal levels. Future experiments will seek to determine how the MHC1 signaling pathway is specifically affected by maternal immune activation.
B. M. Elmer, M. L. Estes, S. L. Barrow, A. K. McAllister. MHCI Requires MEF2 Transcription Factors to Negatively Regulate Synapse Density during Development and in Disease. Journal of Neuroscience, 2013; 33 (34): 13791 DOI:10.1523/%u200BJNEUROSCI.2366-13.2013