Dr. Zhao's laboratory has developed a mouse deficient in the epigenetic gene expression regulator MBD1, which is critical for the functioning of brain regions, such as the amygdala and hippocampus, which are highly involved in autism. These mice show normal prenatal development, but after birth have characteristics similar to individuals with autism, such as impaired learning, increased anxiety, abnormal brain serotonin activity, and deficient hypothalamic-pituitary-adrenal (HPA) axis function. While genetic regulation is crucial for early development and postnatal brain function, many environmental factors (e.g., pollution, diet) can cause changes in genetic expression without altering the DNA code. The proposed research will determine the usefulness of the MBD1 mutant mouse as an animal model of autism, and the role of MBD1 in regulating the serotonin system and HPA axis. In addition, the investigators will examine whether currently available medication to treat autism, in conjunction with dietary methyl-donor supplementation, can correct the traits that MBD1 mutant mice share with autistic individuals. What this means for people with autism: The development of an animal model of autism will advance research on the molecular and cellular basis of autism. The investigators are looking for a link between environmental modulators and such neural developmental disorders, and specifically they seek to determine how anxiety and stress are regulated at epigenetic levels and the relationship of this regulation to the etiology of autism.