Human cellular model of midline crossing to study developmental neurological disorders

ABSTRACT Defects in establishing midline connectivity in the developing human nervous system are associated with multiple neurological disorders. However, there are no self-organizing human cellular models to study midline-guided axonal crossing. My laboratory has been developing methods for guided differentiation of regionalized neural organoids and we have shown that these can combined to study cell-cell interactions and circuit formation in preparations called neural assembloids. Here, we propose to generate a novel human stem cell-derived multi-cellular model of the developmental processes underlying the spinal cord midline crossing of axons. To achieve this, we will generate and functionally characterize organoids that resemble the human floor plate, and then assemble them bilaterally with organoids resembling the dorsal spinal cord to derive midline assembloids and recapitulate midline crossing of human axons. We will then systemically apply this microphysiological system to study axon guidance defects following loss of neurodevelopmental disease genes.