ABSTRACT
A relatively small number of cell bodies located in the region of the ventral midbrain use dopamine (DA) as their neurotransmitter substance. These cells send axons to several forebrain sites including the dorsal and ventral regions of the striatum and the frontal cortex. Their axons branch extensively, each dopaminergic neurone forming hundreds of thousands of synaptic specializations in its terminal region. Although small in number, these elaborately branched cells are in a unique position to modulate connections in the brain between incoming sensory/perceptual messages and outgoing motor signals. In this chapter, we will discuss the role played by these dopaminergic cells in the control of locomotor activity and reward-related incentive learning.
