To determine the effect of DPM activation on the MBs, we expressed P2X2 receptors in DPMs using
the UAS/GAL4 binary expression system and either GCaMP3.0 or EPAC in the MBs using the lexA/
lexAop binary expression system to observe changes in intracellular calcium or cAMP, respectively
(Figure 4A). We found that activation of DPM neurons had no excitatory effects on the MBs when
using either NP2721-GAL4 (Figure 4—figure supplement 1B,C) or the stronger c316-GAL4 with eyeless-
GAL80 and MB-GAL80 to restrict expression to DPM neurons (Figure 4C,D).