Figure 4
From: Role of serotonergic neurons in the Drosophila larval response to light
Response to light of 3rd instar larvae expressing TNT in different subsets of Ddc neurons. A, Foraging stage. B, Wandering stage. Expression of TNTG under control of TH-GAL4 did not affect the larval response to light during 3rd instar, suggesting that dopaminergic neurons do not contribute to the increase in the response to light observed in Ddc:TNT-G larvae (early foraging 3rd instar:UAS-TNT-G/+;TH-GAL4/+, n = 17, RI = 0.30; UAS-TNT-VIF/+;TH-GAL4/+, n = 22, RI = 0.29; ANOVA: F(1,37) = 0.02, p = 0.89; early wandering 3rd instar UAS-TNT-G/+;TH-GAL4/+, n = 30, RI = 0.09; UAS-TNT-VIF/+;TH-GAL4/+, n = 25, RI = 0.09; ANOVA: F(1,53) = 0.01, p = 0.91). On the other hand, CRZ neurons appear to partially contribute to the down-regulation of the larval response to light during foraging as well as wandering stage (early foraging 3rd instar:UAS-TNT-G/+;CRZ-GAL4/+, n = 20, RI = 0.34; UAS-TNT-VIF/+;CRZ-GAL4/+, n = 15, RI = 0.29; ANOVA: F(1,33) = 8.34, p < 0.05; early wandering 3rd instar UAS-TNT-G/+;CRZ-GAL4/+, n = 22, RI = 0.17; UAS-TNT-VIF/+;CRZ-GAL4/+, n = 25, RI = 0.12; ANOVA: F(1,45) = 4.59, p < 0.05). Interestingly, TRH:TNT-G and TRH:TNT-VIF larvae present similar RI values to those observed in Ddc:TNT-G and Ddc:TNT-VIF larvae (early foraging 3rd instar:UAS-TNT-G/TRH-GAL4, n = 21, RI = 0.50; UAS-TNT-VIF/TRH-GAL4, n = 21, RI = 0.33; ANOVA: F(1,40) = 44.4, p < 0.01; early wandering 3rd instar UAS-TNT-G/TRH-GAL4, n = 41, RI = 0.29; UAS-TNT-VIF/TRH-GAL4, n = 27, RI = 0.13; ANOVA: F(1,66) = 68.31, p < 0.01). *** p < 0.001, ** p < 0.01, * p < 0.05.