Although the causes of autism are still unknown, there is growing evidence that genetic, environmental, and immunological factors may contribute to the development of the disorder. Many cases of autism are reported to be associated with chronic activation of the immune system. This experiment will investigate markers of chronic neuroinflammation in brain tissue from individuals affected with autism. These markers will be compared to levels of two newly studied neuroactive compounds which have been associated with cell death: kynurenic acid (KYNA) and quinolinic acid (QUIN). Dr. Vogel and his colleagues will investigate if alterations in the relative abundance of KYNA and/or QUIN affect the development and functioning of neural circuits or induce damage in the nervous system thereby contributing to the development of autism. Significance: Alterations in immune system function has been associated with autism, however, the link between immune reactivity and onset of autism spectrum disorder has not been clearly defined. Changes in KYNA and QUIN in human postmortem tissue along with other neuropathological alterations would help better define the relationship of the immune system in brain development and neurodevelopmental disorders. These results could lead to new targets, possibly those in the immune system, for the development of novel treatments for autism.