High-Frequency Neuronal Bursting is Essential for Circadian and Sleep Behaviors in .

Circadian rhythms have been extensively studied in ; however, still little is known about how the electrical properties of clock neurons are specified. We have performed a behavioral genetic screen through the downregulation of candidate ion channels in the lateral ventral neurons (LNvs) and show that the hyperpolarization-activated cation current I is important for the behaviors that the LNvs influence: temporal organization of locomotor activity, analyzed in males, and sleep, analyzed in females. Using whole-cell patch clamp electrophysiology we demonstrate that small LNvs (sLNvs) are bursting neurons, and that I is necessary to achieve the high-frequency bursting firing pattern characteristic of both types of LNvs in females.