Figure 9.

CO-induced DA release is mediated by RyRs. A, RyR localization was examined in UAS-mCD8::GFP/Mi{Trojan-GAL4.0} RyR[MI08146-TG4.0] flies in which expression of mCD8::GFP is driven by Trojan-GAL4 inserted in the endogenous RyR gene. GFP expression overlapped with expression of TH in PPL1 DA neurons (arrows) that innervate the vertical lobes of the MBs. B, Temporal RyR knockdown at 32°C in TH-DA neurons prevents DA release evoked by AL + NMDA stimulation. Two-way ANOVA indicates significant differences in spH fluorescence between restrictive and permissive temperatures (F_(3,56) = 6.625, p = 0.0007, N = 8 for all data). **p < 0.01 (Bonferroni post hoc tests). C, Temporal knockdown of RyR in TH-DA neurons prevents DA release evoked by CO application. CO-saturated saline was applied during the indicated time period (pink) from a micropipette. Two-way ANOVA indicates significant interaction differences in spH fluorescence due to time, temperature, and interaction between time and temperature (F_(2,42) = 12.6, p < 0.0001, N = 8 for all data). **p < 0.01 (Bonferroni post hoc tests). D, Knocking down RyR in TH-DA neurons abolishes LTE induced by AL + NMDA stimulation. One-way ANOVA and Bonferroni post hoc tests indicate significant increases in AL-evoked Ca²⁺ responses after AL + NMDA stimulation in control brains (F_(2,18) = 5.455, p = 0.014) but not in TH>RyR-KD brains (F_(2,18)= 1.666, p = 0.217). N = 7 for all data. E, Knocking down RyR in TH-DA neurons impairs 1 h olfactory memory (F_(2,28) = 7.735, p = 0.002). *p < 0.01 (Bonferroni post hoc tests). N = 11 for TH-GAL4>RyR-KD and UAS-RyR RNAi, and N = 12 for TH-GAL4. F, Naive responses to odors and electrical shock are not affected by knocking down RyR in TH-DA neurons (Shock: F_(2,19) = 1.213, p = 0.319, N = 9 for TH-GAL4>RyR-KD, N = 7 for UAS-RyR RNAi, and N = 6 for TH-GAL4; OCT: F_(2,19) = 1.564, p = 0.235, N = 10 for TH-GAL4>RyR-KD, N = 6 for UAS-RyR RNAi and TH-GAL4; MCH: F_(2,15) = 0.669, p = 0.527, N = 6 for all genotypes).