Circadian rewiring of adult networks in Drosophila.

CERIANI MF

Amelia Island, Florida

Congreso; Biannual meeting of the Society for Research on Biological Rhythms; 2018

Society for Research on Biological Rhythms,

Ventral lateral neurons (LNvs) are essential in the control of rest-activity rhythms in Drosophila melanogaster. A few years ago our lab reported that these clock neurons undergo circadian remodeling of their axonal projections, a phenomenon called circadian structural plasticity (Fernández et al., 2008). Axonal arborizations display higher complexity during the day and less so at night, and this remodeling involves changes in the degree of connectivity (Gorostiza et al., 2014). We also have demonstrated that this phenomenon depends on the clocks present within the LNvs as well as those in glia (Herrero et al., 2017) .In this work we characterize in detail the role of the PIGMENT DISPERSING FACTOR (PDF) neuropeptide and study its contribution to structural plasticity at different times of the day. Using different genetic strategies to temporally restrict its downregulation , we demonstrate that subtly altering PDF cycling at the dorsal protocerebrum correlates with impaired rremodeling; both, PDF released by the sLNvs and the lLNvs contribute to the process. Quite unexpectedly, although a sharp decrease in PDF levels result in greater complexity of the terminals that remains unchanged throughout the day, a sustained reduction is associated with less complexity. This dual response is interesting in itself. Finally, we provide evidence suggesting that PDF action on structural plasticity recruits activity-dependent mechanisms, which operate differentially across the day.