Serotonin in the Cerebellum

Serotonin (5-hydroxytryptamine, 5-HT) is widely present in the brain, including in the cerebellar cortex and cerebellar nuclei, which are richly innervated by serotonergic fibers. A variety of serotonin receptors mediate the complex effects of serotonergic modulation of the cerebellum. These serotonin receptors all have their own specialized role but share some similar effects. It is through the temporally and spatially restricted expression of these different serotonin receptors in the cerebellum that such a widely expressed neurotransmitter as serotonin can exert very specific functions. These functions include regulation of neuronal activity, synaptic transmission, and cerebellar development, as well as aging. Disruptions to the serotonergic system in the cerebellum can lead to movement- and cognition-related disorders.