NrCAM, an axon guidance molecule (human chromosome 7q31.1 – 31.2), has been recently identified in genetic association studies as a candidate susceptibility gene for autism spectrum disorders (ASD). Abnormal visual processing may be causally related to ASD deficits of eye gaze and interpretation of facial expression, which contribute to impaired social interaction, and deficits in motion perception and movement toward visual stimuli. This project will provide insight into visual system development and its pathology associated with autism that may arise from mutations in the NrCAM gene. Dr. Maness will study mutant mice lacking NrCAM to investigate the hypothesis that NrCAM mediates formation of the precise connections between the axons from the retina and their targets in the brain. This will serve as a potentially new model for visual processing deficits in ASD. This project will use a variety of molecular techniques to characterize in detail what happens to connections from the eye to the brain when NrCAM function is disrupted. Abnormalities in visual processing may also impair social communication and motor responses, thus NrCAM mutant mice and controls will be analyzed for behaviors relevant to ASD, including impaired sociability, sensorimotor gating, and learning. What this means for people with autism: Knowledge gained from this research could contribute to the diagnosis and molecular understanding of autism, and will encourage genetic studies of NrCAM polymorphisms associated with autistic patient populations.