Fig. 2

Scheme showing autocrine or paracrine secretion of dopamine from cells expressing dopamine-synthetic enzyme and ATPVC6. Dopamine (DA) is synthetized by AAV-TH/-AADC/-GCH in astrocytes, neurons, and iPSC (yellow) GABAnergic neurons (brown). DA release from the cell soma through the stalk or pore of ATPV0C6. DA released from adjacent cells (paracrine) or GABAnergic neurons (autocrine) binds to DA receptors at the synaptic or non-synaptic domains on GABAnergic neurons. GABAnergic neurons relay signals via DA receptors activated by DA from dopaminergic neurons in the substantia nigra in intact tissue. In the PD brain, DA released in an autocrine or paracrine fashion activates DA receptors