Serotonin regulation of striatal function

Abstract Serotonin plays an important yet underappreciated role in the physiology and function of the striatum, impacting numerous behaviors including reward seeking, decision-making, and motor planning. This review discusses how the anatomical pattern of innervation of striatum by serotonergic neurons from midbrain raphe and the complex distribution of serotonin receptors within striatum impact how serotonin modulates the striatal function. We highlight data from studies employing in vivo microdialysis to discuss the neurochemistry of striatal serotonin receptors with respect to their role on serotonin and dopamine release. Finally, we discuss behaviors impacted by serotonin in the striatum and attempt to provide a framework to understand the complicated role of serotonin in modulating the striatum neurochemically, behaviorally, and functionally.