Methods and compositions for inducing a plurality of mutations in transgenic Cas9 eukaryotes to model a neuronal disease or disorder. The invention further comprehends testing putative treatments with such models, e.g., testing putative chemical compounds that may be pharmaceutically relevant for treatment or gene therapy that may be relevant for treatment, or combinations thereof. The invention allows for the study of genetic diseases and putative treatments to better understand and alleviate a genetic disease or a condition, e.g., autism, autism-spectrum disease or disorder, obsessive-compulsive disorder, or psychiatric disorders.