Loss of slowpoke function impairs circadian pacemaker circuitry

MF FERNÁNDEZ AND MF CERIANI

Sandestin, Florida, USA

Congreso; X meeting Society for Biological Rhythms; 2006

Society for Biological Rhythms

In the last decade substantial progress has been made in elucidating the molecular processes that impart a temporal control over cell metabolism and behavior, but it was not until recently that the hierarchical organization among the different circadian circuits has been addressed.  Circadian release of the neuropeptide pigment dispersing factor (PDF) is central to how the clock controls rhythmic rest-activity cycles.Drosophila mutants in the slowpoke BK potassium channel display an arrhythmic phenotype both under entrained and free running conditions.  Lack of SLO function specifically affected PDF staining on projections towards the pars intercerebralis and along the midline.  Moreover, not only it impaired PDF circadian release on dorsal projections from pacemaker neurons, but it also altered the normal arborization of the axon terminals at this level, suggesting an impaired contact with PDF postsynaptic targets.  We are currently investigating the role of synaptic activity and other factors potentially affecting the structure of this relevant circuit and its connection to rhythmic behavior employing a UAS-gfp reporter tethered to the membrane to follow its morphology under different developmental and temporal conditions.