PDF receptor-expressing neurons in the ellipsoid body: a link between the locomotor and sleep circuits?

PÍREZ, NICOLÁS; GRIFFITH, LESLIE C.

Huerta Grande

Congreso; XXVII Congreso Anual de la Sociedad Argentina de Investigacion en Neurociencias; 2012

SAN

The peptide PDF is an important regulator of the circadian clock in insects. pdfR-GAL4 drives expression in ellipsoid body (EB) cells, a component of the central complex. This suggests that the EB may provide an important link between the clock and sleep/activity circuits. How the circadian clock and sleep deprivation might affect the activity of this group of neuronswas unknown. To approach this issue, we performed whole brain optical imaging experiments using flies that expressa FRET-based cAMP sensor under the control of the pdfR promoter. Basal cAMP levels were insensitive to time of day and to 1 cM TTX, but were reduced by mutation of the pdfR gene.Bath application of PDF caused a significant change in the cAMP level of EB cells which was blocked by mutation of the pdfR gene.ACh was found to cause a significant increase in cAMP levels, which had both direct and indirectcomponents,implying thatACh is able to stimulate inputs to EB during the day that increases cAMP.To test the effect of sleep deprivation (SD), we sleep deprived the flies for 12h prior to imaging. Although the effect of SD is clear at the behavioral level, the cAMP responses of these cells to either PDF or AChremained similar to non- SD controls, suggesting that cyclase coupling is not modulated by SD.