Neuromodulatory Actions of Dopamine and Cholecystokinin in the Ventral Striatum

Electrophysiological investigations of the cellular actions of dopamine had focused in the past on its direct action on cell bodies of the postsynaptic neuron, assuming dopamine to be a neuromediating transmitter. Recent evidence suggests, however, that while dopamine undoubtedly has actions on the cell bodies of postsynaptic neurons, it may also have an important presynaptic neuromodulatory action on non-dopaminergic inputs to the ventral striatum (see Yim and Mogenson, 1986). There is also evidence that peptides such as cholecystokinin which coexists with dopamine in a subpopulation of the mesolimbic dopamine neurons may in turn modulate the neuromodulatory action of dopamine.