Modeling cell-cell interactions in the brain using cerebral organoids.

Until recently, a great amount of brain studies have been conducted in human post mortem tissues, cell lines and model organisms. These researches provided useful insights regarding cell-cell interactions occurring in the brain. However, such approaches suffer from technical limitations and inaccurate modeling of the tissue 3D cytoarchitecture. Importantly, they might lack a human genetic background essential for disease modeling. With the development of protocols to generate human cerebral organoids, we are now closer to reproducing the early stages of human brain development in vitro. As a result, more relevant cell-cell interaction studies can be conducted. In this review, we discuss the advantages of 3D cultures over 2D in modulating brain cell-cell interactions during physiological and pathological development, as well as the progress made in developing organoids in which neurons, macroglia, microglia and vascularization are present. Finally, we debate the limitations of those models and possible future directions.