Functional plasticity in the organization of signaling complexes in the striatum.

Dopamine plays a prominent role in regulating fast synaptic transmission in the striatum. Following dopamine receptor stimulation, various signal transduction pathways are activated, leading to the altered phosphorylation state and functional activity of substrate proteins, including glutamate-gated ion channels. Protein phosphatase 1 (PP1) plays a central role in these events. Recent studies have revealed a system for targeting PP1 to specific substrates in dendritic spines, via association with the cytoskeletal scaffolding proteins, spinophilin and neurabin. Interactions between these proteins and the actin cytoskeleton are dynamically regulated by the cAMP pathway, and thus play a role in dopamine-mediated striatal plasticity.