Activation of ventral pallidum-projecting neurons in the nucleus accumbens via 5-HT receptor stimulation regulates motivation for wheel running in male mice.

Rodents have a strong motivation for wheel running; however, the neural mechanisms that regulate their motivation remain unknown. We investigated the possible involvement of serotonin (5-HT) systems in regulating motivation for wheel running in male mice. Systemic administration of a 5-HT receptor antagonist (WAY100635) increased the number of wheel rotations, whereas administration of a 5-HT or 5-HT receptor antagonist (volinanserin or SB242084, respectively) decreased it.

A spatiotemporal increase of neuronal activity accompanies the motivational effect of wheel running in mice.

Spatiotemporal patterns of neuronal activity underlying the motivational effect of rotating running wheels (RWs) in rodents remain largely undetermined. Here, we investigated changes of neuronal activity among brain regions associated with motivation across different intensities of motivation for RWs in mice. Daily exposure to RWs gradually increased rotation number, then became stable after approximately 3 weeks.