predominantly extrasynaptic DA autoreceptors on DA axons and heteroreceptors on neighboring cells. In this model the sphere of influence for high affinity DA receptors has a volume of several tens of μm3, and may therefore affect thousands of synapses of many neurons simultaneously. Conditional transgenic mouse lines or cell specific knockouts of GIRK channel subunits are among the future studies that are required to specifically investigate the role of GIRK channels in signaling pathways beyond the direct hyperpolarization.
