Activation of 5-HT neuronal activity during motor behavior

Brain serotonin (5-HT) neuronal activity is activated preferentially in association with motor activity. This is especially clear during changes in tonic motor output and during repetitive responses mediated by central pattern generators, such as locomotion, respiration and chewing. These and other data support the hypothesis that the primary function of the brain serotonin system is to facilitate motor output. Concurrently, the system coordinates autonomic and neuroendocrine function with the present motor demand, and inhibits information processing in various sensory pathways. Reciprocally, when the serotonin system is briefly inactivated (e.g. during focussed attention), this disfacilitates motor function and disinhibits sensory information processing.