Mouse vs man: Organoid models of brain development & disease.

Brain organoids have rapidly become established as promising tools for studying both the normal embryonic development of the brain and the mechanistic roots of neurodevelopmental disorders. Most recent studies are based on brain organoids derived from human pluripotent stem cells (PSCs), as these are likely to be the best way to understand normal human development and disease. However, brain organoids grown from mouse cells still have a role to play. We discuss recent work showing how mice and mouse organoids can be employed to complement studies using human organoids. Mouse stem cell-derived organoids are useful for the development of improved protocols to generate organoids, including brain region-specific organoids. Importantly, the wealth of existing in vivo data on mouse brain development together with detailed descriptions of mutant phenotypes provide invaluable points of comparison to validate organoids as tools to study the genetics of brain development. Further, organoids have significant potential to replace or reduce the numbers of animals used in studies of normal brain development.