From Organoids to Assembloids: Experimental Approaches to Study Human Neuropsychiatric Disorders

To understand the pathophysiology and develop effective therapeutics for brain disorders, some of which may involve uniquely human features of the nervous system, scalable human models of neural cell diversity and circuit formation are essential. The discovery of cell reprogramming and the development of approaches for generating stem cell–derived neurons and glial cells in 3D preparations known as neural organoids and assembloids, both in vitro and following transplantation in vivo, provide new opportunities to tackle these challenges. Here, we outline strengths and limitations of currently available human experimental models as applied to neurological and psychiatric disorders for both environmental and genetic risk factors, and we discuss how these new tools hold promise for accelerating the development of therapeutics.