Article Figures & Data
Figures
- Figure 1.
FC and extinction in S1-DAT-Cre, BL6-DAT-Cre, S1 and BL6 mice. A, Experimental protocol for behavioral tests. B, The percentage of time spent freezing during pre-CS periods or indicated CS presentations or blocks throughout the experimental paradigm. All groups increased freezing levels during FC. However, S1-DAT-Cre and S1 mice were freezing higher than BL6-DAT-Cre and BL6 mice during CS3, and also, S1 mice froze more than S1-DAT-Cre mice. At the beginning of the first extinction session (EXT1), all strains exhibited similar freezing levels. BL6 and BL6-DAT-Cre mice showed reduced freezing levels during the second extinction session (EXT2); S1 and S1-DAT-Cre mice maintained high freezing. During extinction retrieval (RET), S1-DAT-Cre and S1 mice again exhibited high freezing levels, as compared with BL6-DAT-Cre and BL6 mice. Note that S1 and S1-DAT-Cre mice overlapping data points on Extinction 2 (first-third data points) and retrieval (first block). S1-DAT-Cre (red circle), n = 12; S1 (pink triangle), n = 10; BL6-DAT-Cre (blue circle), n = 20; BL6 (light blue triangle), n = 22. Data are means ± SEM for the indicated time periods (pre-CS, single CS, or 5-CS average blocks). C, Immunostaining for TH with representative image and atlas coordinates of cells counted relative to the bregma (S1 n = 7; BL6 n = 6). D, Similar number of TH+ cell bodies in S1 and BL6 mice along the anterior–posterior axis. CTX, context; US, unconditioned stimulus; CS, conditioned stimulus. Data are means ± SEM for a section between the bregma −2.9 and −3.8 mm from the bregma. Extended Data Figure 1-1 supports this figure.
- Figure 2.
FC and extinction during fiber photometry. A, AAV injection and implantation scheme. B, Representative image of AAV expression and optic fiber tip locations in the VTA. C, Experimental protocol for all behavioral tests. D, The percentage of time spent freezing during pre-CS periods or indicated CS presentations or blocks throughout the experimental paradigm. Both strains showed increased freezing during FC, although S1-DAT-Cre mice exhibited generally higher freezing levels. During extinction training (EXT), freezing was decreased to a different extent in S1-DAT-Cre and BL6-DAT-Cre mice and S1-DAT-Cre mice showed more freezing than BL6-DAT-Cre mice during extinction retrieval (RET). CTX, context; US, unconditioned stimulus; CS, conditioned stimulus. Data are means ± SEM for the indicated time periods (pre-CS, single CS, or 5-CS average blocks). Extended Data Figures 1-1 and 2-1 support this figure.
- Figure 3.
Fiber photometry during FC and extinction. Graphs show average Z-scores of changes in fluorescence (dF/F) during CS presentation, baselined to 5 s before CS onset or CS offset, along with corresponding time-normalized AUC values. A, Fluorescence values during CS onset periods (0–5 s) of FC were higher in S1-DAT-Cre than in BL6-DAT-Cre mice. B, Similarly increased fluorescence during US delivery and at US offset in S1-DAT-Cre and BL6-DAT-Cre animals. C, During early EXT (First 10 CS trials), S1-DAT-Cre and BL6-DAT-Cre mice exhibited similar fluorescence at CS onset. D, Similarly increased at early EXT CS offset in both strains. E, During late EXT (last 10 CS trials), fluorescence at CS onset was less in BL6-DAT-Cre, but not in S1-DAT-Cre mice, as compared with early EXT. F, Fluorescence at US omission at late EXT remained similarly high in both strains. G, No change in fluorescence at CS onset during RET in either strain. H, S1-DAT-Cre mice had higher fluorescence at US omission than BL6-DAT-Cre mice during RET. S1-DAT-Cre GCaMP6 (red), n = 9; BL6-DAT-Cre GCaMP6 (blue), n = 6. Data are means ± SEM. Extended Data Figures 1-1–3-3 support this figure.
- Figure 4.
Optogenetic excitation of VTA-DAergic cell bodies during US omission in S1-DAT-Cre mice. A, AAV injection and implantation scheme. B, Representative image of AAV expression and optic fiber tip locations in the VTA. C, Experimental protocol for all behavioral tests. D, Freezing levels during pre-CS periods and indicated CS presentations or blocks. The opsin groups showed CS-related freezing during fear acquisition (FC). Optogenetic activation of VTA-DA neurons during US omission did not alter CS-related freezing during extinction training (EXT) or retrieval (RET). The opsin groups showed similar CS-related freezing levels during RET, as compared with the first CS block of extinction. S1-DAT-Cre ChR2-Cherry (blue), n = 12; S1-DAT-Cre mCherry (red), n = 10. CTX, context; US, unconditioned stimulus; CS, conditioned stimulus. Data are means ± SEM for the indicated time periods (pre-CS, single CS, or 5-CS average blocks). Extended Data Figures 1-1 and 4-1 support this figure.
- Figure 5.
Optogenetic excitation of IL DAergic terminals during US omission in S1-DAT-Cre mice. A, AAV injection and implantation scheme. B, Representative image of AAV expression and optic fiber tip locations in the VTA. C, Experimental protocol for all behavioral tests. D, Freezing levels during pre-CS periods and indicated CS presentations or blocks. The opsin groups showed similar CS-related freezing during fear acquisition (FC). Optogenetic activation of VTA-DA axons in IL during US omission had no effect on CS-related freezing during extinction training (EXT) or retrieval (RET). The opsin groups showed similar freezing levels on RET, compared with the first CS block of extinction. S1-DAT-Cre ChR2-Cherry (blue), n = 9; S1-DAT-Cre mCherry (red), n = 11. CTX, context; US, unconditioned stimulus; CS, conditioned stimulus. Data are means ± SEM for the indicated time periods (pre-CS, single CS, or 5-CS average blocks). Extended Data Figures 1-1 and 5-1 support this figure.
Extended Data
Figure 1-1
Statistical results. ANOVA: analysis of variance, RM: repeated-measures, base: baseline, Veh: vehicle, YFP: yellow fluorescent protein, ChR2: channelrhodopsin2. For comparing two groups Student’s t-test (paired or unpaired) was used except where indicated. Data has normal distribution unless stated otherwise. Download Figure 1-1, DOCX file.
Figure 2-1
Fiber placement maps for fiber photometry experiments. A. Optical fiber placements for the fiber photometry experiments with S1-DAT-Cre mice (CS-US; n=9). B. Optical fiber placements for the fiber photometry experiments with BL6-DAT-Cre mice (CS-US; n= 7). Download Figure 2-1, TIF file.
Figure 3-1
Fiber photometry Ca2+ measurements in the VTA during CS/no-US fear conditioning. All graphs show average Z-scores of changes in fluorescence (dF/F) for CS presentations baselined to 5 seconds before CS onset or CS offset and corresponding AUC values. A. There was no strain difference in fluorescence after CS onset during fear conditioning. B. Fluorescence at CS offset (2 seconds without US delivery) was similar between S1-DAT-Cre and BL6-DAT-Cre mice. C. During early EXT (First 10 CS trials), fluorescence at CS onset was not significantly different between strain. D. Fluorescent was not different between strains at US omission during early EXT. E. During late EXT (Last 10 CS trials), fluorescence at CS onset was not different between strains. F. During late EXT, fluorescence at US omission was similar across strains. G and H. Both strains no change in fluorescence at CS-onset and CS-offset during RET. S1-DAT-Cre GCaMP6 (red): n=4; BL6-DAT-Cre GCaMP6 (blue): n=3. Data are means ± SEM. Download Figure 3-1, TIF file.
Figure 3-2
Fiber placement maps for fiber photometry experiments. A. Optical fiber placements for the fiber photometry experiments with S1-DAT-Cre mice (CS-only; n=4). B. Optical fiber placements for the fiber photometry experiments with BL6-DAT-Cre mice (CS-only; n=3). Download Figure 3-2, TIF file.
Figure 3-3
Fiber photometry Ca2+ measurements in the VTA during CS offset in Early Extinction and Retrieval. All graphs show average Z-scores of changes in fluorescence (dF/F) for CS presentations baselined to 5 seconds before CS offset and corresponding AUC values. A. There was a significant difference in fluorescence at CS offset in BL6-DAT-Cre mice (n=6) on RET compared to early EXT (First 10 CS trials). B. Fluorescence at CS offset remained the same in S1-DAT-Cre mice (n=9) on RET compared to early EXT. Data are means ± SEM. Download Figure 3-3, TIF file.
Figure 4-1
Optrode placement maps for optogenetic experiments (VTA). A. Optrode placements for the S1-DAT-Cre mCherry group shown in Figure 4 (n=10). B. Optrode placements for the S1-DAT-Cre ChR2 group shown in Figure 4 (n=12). Download Figure 4-1, TIF file.
Figure 5-1
Optrode placement maps for optogenetic experiments (VTA-IL). A. Optrode placements for the S1-DAT-Cre mCherry group shown in Figure 5 (n=11). B. Optrode placements for the S1-DAT-Cre ChR2 group shown in Figure 5 (n=9). Download Figure 5-1, TIF file.
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