There is a cause-and-effect relationship in all pathological changes that occur in our body. No change occurs by chance. They have pathways and mechanisms. These mechanisms are being illuminated more accurately with scientific research every passing day. There is scientific evidence for the pathological changes that occur in the brain in autism. 1. Experimental animal modeling studies; 2. Cell culture studies conducted with human nerve cell cultures; and 3. Post-mortem autopsy studies conducted with special permission on the brains of people who died with a diagnosis of autism.