Disclosed are methods that include separately differentiating stem cells to form cortical neural progenitor cells and differentiating stem cells to form dopaminergic neural progenitor cells. The cortical progenitor cells are transferred to a first compartment of a culture dish and the dopaminergic progenitor cells are transferred to a second compartment of the culture dish, separated by a removable barrier. The cortical progenitor cells and dopaminergic progenitor cells are cultured in medium that promotes differentiation of cortical neurons and dopaminergic neurons, respectively. The barrier is then removed, creating a single chamber containing the cortical progenitor cells and the dopaminergic progenitor cells, separated by a gap. The cortical progenitor cells and the dopaminergic progenitor cells are then cultured in a single medium, which promotes further differentiation of the neurons and also supports formation of connections (such as synapses or synapse-like structures) between at least some of the cortical neurons and dopaminergic neurons.
Modeling connections between dopaminergic neurons and the cerebral cortex