Figure 7. Notch activation in olfactory receptor neurons is modulated by synaptic activity of local interneurons in the antennal lobe.

N-LV LexOP.dGFP/tubP-gal80^ts20 flies carrying Kra.Gal4, LN1.Gal4, or LN2.Gal4 drivers and either the UAS.IMPTNT-Q4-A (IMP) or UAS.TNT-E (TNT) transgene, as indicated, were raised to eclosion on molasses food and aged for two to four days on dextrose food at 18° C. They were then transferred to 30°C for four days and exposed at 30°C to a 1:100 dilution of geranyl acetate for four more days or to 5% CO₂ (Kra.GAL4 and LN2.GAL4) or 10% CO₂ (LN1.GAL4) for three more days, as indicated. TNT expression under the control of each of the three LN drivers significantly altered the level of dGFP accumulation in response to either, or both, geranyl acetate and CO₂, in the appropriate target glomerulus (VA6 for geranyl acetate and V for CO₂). In the cartoons, darker shades of green indicate increased Notch activity. For each set of experiments, the graphs depict box plots of fluorescence in VA6 (geranyl acetate exposed flies) or V (CO₂ exposed flies). The number of samples analyzed for each genotype and odor was: Kra>IMP geranyl acetate, 14; Kra>TNT geranyl acetate, 26; Kra>IMP CO₂, 33; Kra>TNT CO₂, 27; LN1>IMP geranyl acetate, 25; LN1>TNT geranyl acetate, 28; LN1>IMP CO₂, 41; LN1>TNT CO₂, 33; LN2>IMP geranyl acetate, 30; LN2>TNT geranyl acetate, 26; LN2>IMP CO₂, 32; LN2>TNT CO₂, 24.