Figure 1.

The dopaminergic synapse. DA is derived from the L-tyrosine metabolism to L-dopa mediated by TH and AADS; the DA transport into synaptic vesicles is operated by VMAT-2; the DA synthesis is regulated via presynaptic auto-receptors (in blue); the presynaptic neuron releases DA (red circles); DA binds two main types of receptors (D1 family formed by D1-D5 receptors and D2 family formed by D2-D3-D4 receptors) on the post-synaptic neuron; presynaptic DAT (in yellow) regulates the DA reuptake from the extracellular fluid. Abbreviations: DA, Dopamine; AADC, aromatic L-amino acid decarboxylase; DAT, dopamine transporter; TH, tyrosine hydroxylase; VMAT-2, vesicular monoamine transporter 2.