FIGURE 3.
An updated model for modulation of synaptic vesicle release at dopaminergic neuron synapses. Fusion of acidified neurotransmitter vesicles with the synaptic membrane causes release of dopamine and H+ ions. Dopamine activates a feedback loop through auto-receptors (DOP-2), and possibly through the membrane transporter (DAT-1), while ASIC-1 functions to facilitate a positive feedback loop that reinforces dopamine release in response to a local pH drop in the synaptic cleft. Thus, DOP-2, DAT-1 and ASIC-1 form a modulatory hub responsible for fine-tuning synaptic dopamine levels