Dopaminergic modulation of neuronal excitability in the striatum and nucleus accumbens

The striatum and its ventral extension, the nucleus accumbens, are involved in behaviors as diverse as motor planning, drug seeking, and learning. Inv ariably, these striatally mediated behaviors depend on intact dopaminergic innervation. However, the mechanisms by which dopamine modulates neuronal f unction in the striatum and nucleus accumbens have been difficult to elucid ate. Recent electrophysiological studies have revealed that dopamine alters both voltage-dependent conductances and synaptic transmission, resulting i n state-dependent modulation of target cells. These studies make clear pred ictions about how dopamine, particularly via D-1 receptor activation, shoul d alter the responsiveness of striatal neurons to extrinsic excitatory syna ptic activity.