The narrow abdomen ion channel is essential for nerve signals in the fruit fly's biological clock

Drosophila mutants lacking the narrow abdomen (na) ion channel display poor circadian rhythms and suppressed daylight activity.

• NA is expressed in pacemaker neurons involved in regulating circadian rhythms.
• Inducing expression of na in circadian neurons can restore normal rhythmic behavior in mutants.
• Rescue of rhythmicity varies based on selective na expression in specific pacemaker neurons.
• The clock protein PERIOD shows normal oscillations in na mutants, suggesting NA's role is in neuronal output rather than clock function.
• In na mutants, increased levels of potassium currents and the neuropeptide PDF indicate altered neurochemical signaling.

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