Figure 1.

Schematic of dopamine model. (a) Dorsal striatum with medium spiny neurons (MSN, red contours/gray body), dopamine terminals (yellow), and projection axons (tan) from SNc. (b) Magnified view of an individual dopamine terminal forming a synapse onto a dendritic shaft of MSN. Dopamine release: An action potential causes a dopamine-containing vesicle to release dopamine into the synaptic cleft. Dopamine encounters postsynaptic receptor proteins, triggering further downstream neuronal processes. Dopamine reuptake: DATs clear dopamine from the ECS to be recycled. (c) Space discretization around a dopaminergic terminal representing tortuous morphology of brain tissue. Black represents tissue surrounded by void ECS. Concentric circles depict simulation volume elements. Inset graph: Dopamine concentration fluctuates in space and time as a result of release, diffusion, and reuptake.