Brain organoids as a model system for human neurodevelopment in health and disease

Organoids are three-dimensional cell cultures derived from mammalian stem cells that recapitulate key aspects of embryonic organ development and morphogenesis. In particular, brain organoids are cell cultures designed to mimic aspects of embryonic brain development. These systems exhibit remarkable self-organization of shape and cell fate. Brain organoids allow us to study a variety of neurodevelopmental phenomena ranging from early developmental events such as neuronal differentiation and migration to later events such as synapse formation and network activity. Importantly, brain organoids can be derived from human origin and thus offer the possibility to study human brain developmental disorders such as lissencephaly and schizophrenia. In the first part of this chapter, we discuss the relevance of human brain organoid systems to embryonic development and review the key neurodevelopmental phenomena that have been observed in organoids. In the second part of the chapter, we provide an overview of the use of brain organoid as a platform to study and understand neurodevelopmental disorders.