Figure 5. Chemogenetic Activation and Conditional Tph2 Knockout Reveal that Both DRSert→OFC and DRSert→CeA Neurons Suppress Locomotion.
(A, B) Chemogenetic activation of DRSert→OFC (A) and DRSert→CeA (B) neurons. (A1, B1) Schematic for experimental (Exp) groups. Conditions for the two controls (Ctrl) are listed below. (A2, B2) Confocal images of coronal sections showing the expression of hM3Dq-2A-mCherry (red), and co-labeling with Tph2 staining (green) in the DR. Dotted lines are aqueduct borders. Scale, 100 μm. Right, high magnification images of neurons indicated by arrows. Scale, 50 μm. See Table S4 for cell counts.
(C, D) DRSert→OFC (C) and DRSert→CeA (D) neurons were Tph2 depleted by bilaterally injecting AAVretro-Cre into OFC (C1) or CeA (D1) of the Tph2flox/flox mice. (C2, D2) Confocal images of coronal sections showing the expression of Cre-2A-GFP (green), almost all of which were negative from Tph2 staining (red) in the DR. (Cells counts: Exp DRSert→OFC group, 272±67.9, 98.6%±0.43% were Tph2−; Exp DRSert→CeA group, 331±76.6, 98.7%±0.33% were Tph2–. Ctrl DRSert→OFC group, 160±8.5, 16.7%±0.18% were Tph2–; Ctrl DRSert→CeA group, 177±42.2, 39.2%±0.16% were Tph2–; n=3 mice for all groups). Scale, 100 μm. Right, high magnification images showing neurons indicated by arrows. Scale, 25 μm.
(E) Chemogenetic activation of DRSertĺOFC neurons decreases distance traveled (one-way ANOVA followed by multiple t-tests; F(2, 31) = 4.42, t=2.672, 2.29. n= 9, 11, 14). *p<0.05.
(F) Conditionally knocking out Tph2 from DRSertĺOFC neurons does not have a significant effect on distance traveled (two-tail unpaired t-test, t=1.24, df=17; n=9, 10).
(G) Activation of DRSert→CeA neurons decreases distance traveled (one-way ANOVA followed by multiple t-test; F(2, 30) = 4.516; t=2.21, 2.83. n= 10, 11, 12). *p<0.05.
(H) Conditionally knocking out Tph2 from DRSert→CeA neurons increases distance traveled (two-tail unpaired t-test, t=5.07, df=14. n=8, 8). ***p<0.001. Error bars, SEM.