Patterning ganglionic eminences in developing human brain organoids using a morphogen-gradient-inducing device

In early neurodevelopment, the central nervous system is established through the coordination of various neural organizers directing tissue patterning and cell differentiation. Better recapitulation of morphogen gradient production and signaling will be crucial for establishing improved developmental models of the brain in vitro. Here, we developed a method by assembling polydimethylsiloxane devices capable of generating a sustained chemical gradient to produce patterned brain organoids, which we termed morphogen-gradientinduced brain organoids (MIBOs). At 3.5 weeks, MIBOs replicated dorsal -ventral patterning observed in the ganglionic eminences (GE). Analysis of mature MIBOs through single -cell RNA sequencing revealed distinct dorsal GE -derived CALB2+ interneurons, medium spiny neurons, and medial GE -derived cell types. Finally, we demonstrate long-term culturing capabilities with MIBOs maintaining stable neural activity in cultures grown up to 5.5 months. MIBOs demonstrate a versatile approach for generating spatially patterned brain organoids for embryonic development and disease modeling.