Some neuropsychiatric disorders often develop over time and their pathophysiology is often complex and may not benefit from in vitro disease modeling. Rodent brains with grafted human neurons allow the study of multifaceted and shifting environmental settings on patient derived human iPS cells. When undifferentiated human ES cells were injected directly into the brain ventricles of fetal mice this resulted in the production of human neurons and glia (Muotri, Nakashima, Toni, Sandler, & Gage, 2005). Amazingly, human adult neural stem cells survive, migrate and express the appropriate differentiation markers used to identify neurons and oligodendrocytes, following long-term engraftment in a mouse model for spinal cord injury (Cummings et al., 2005; Guzman et al., 2007). In fact, neonatal mice grafted with human glial progenitor cells yield adult mice whose brains are chimeric for human glial cells (Goldman, Nedergaard, & Windrem, 2015; Windrem et al., 2014) and SCZ glial chimeric mice have broad behavioral and sleep abnormalities (Windrem et al., 2017). This approach is extremely intriguing, we speculate that human glial or neurons derived from iPS cells derived from subjects with AUDs,
