The Drosophila Ih channel shapes circadian rhythms and sleep through the control of neuronal bursting frequency

LIA FRENKEL; M FERNANDA CERIANI; FLORENCIA FERNANDEZ-CHIAPPE; ANA RICCIUTI; CARINA C. COLQUE; NARA I MURARO

Congreso virtual debido a pandemia de COVID19

Congreso; XXXV Congreso Anual de la Sociedad Argentina de Investigación en Neurociencias; 2020

Sociedad Argentina de Investigación en Neurociencias

Circadian rhythms have been extensively studied in Drosophila, 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 Ih is important for the behaviors that the LNvs command: temporal organization of locomotor activity and sleep. Using whole-cell patch clamp electrophysiology we demonstrate that small LNvs are bursting neurons, and that Ih is necessary to achieve the high frequency bursting firing pattern characteristic of both types of LNvs. Since firing in bursts has been associated to neuropeptide release, we hypothesized that Ih would be important for LNvs communication. Indeed, we demonstrate that Ih is fundamental for the recruitment of PDF filled dense core vesicles to the terminals at the dorsal protocerebrum and for their timed release, affecting the temporal coordination of circadian behaviors.