A Peptidergic Circuit Links the Circadian Clock to Locomotor Activity

The DH44 receptor 1 is identified as the relevant receptor for rest:activity rhythms in Drosophila.

• Clock neurons in the Drosophila brain are involved in regulating an approximately 24-hour rhythm of locomotor activity.
• The study mapped the action of DH44 receptor 1 to hugin-expressing neurons in the subesophageal zone (SEZ).
• A circuit was traced from DH44-expressing neurons in the pars intercerebralis through hugin+ SEZ neurons to the ventral nerve cord.
• Hugin neuropeptide, an ortholog of neuromedin U, also influences behavioral rhythms.
• The DH44 PI-Hugin SEZ circuit primarily regulates circadian locomotor activity while having minimal impact on feeding rhythms.
• These findings illustrate a linear peptidergic circuit that connects the circadian clock to motor outputs.

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