Fig. 2
Optogenetic activation of dopamine D1 receptor in Island cells inhibit TFC. A Cre-dependent OptoD1-eYFP expression in Island cells of MEC. B Parasagittal sections of MEC, which was injected by AAV-EF1a-DIO-OptoD1-eYFP, immunostained with anti-GFP (green) and anti–Wfs1 (red). The white-dotted lines indicate the fiber track. Scale bar, 200 μm. C Time course of freezing responses (%) in OptoD1-eYFP (purple) or eYFP (black) groups during the conditioning with a 20-s trace period on day 1. Gray and orange bars represent 20-s tone and shock representations, respectively. Two-way repeated measure ANOVA (n = 9, 8; F(35, 525) = 0.6691, P = 0.928) D Time course of freezing responses (%) during testing session on day 2. Gray bars indicate 60-sec tone representations. Two-way repeated measure ANOVA (F(48, 720)=1.487, P = 0.020). E The averaged freezing responses (%) over the three bins during each tone period and that of the first one min, second and third post-tone periods. Unpaired t-test, (Tone: t15 = 5.284, P < 0.0001, 1min: t15 = 3.214, P = 0.0058, 2 min: t15 = 3.218, P = 0.0058, 3 min: t15 = 2.603, P = 0.02). F Time course of freezing responses (%) during the testing session on day3 in the conditioned context (left). Two-way repeated measure ANOVA (F(16, 111) = 0.8329, P = 0.6462). The averaged freezing responses (%) (right). Unpaired t-test, (t15 = 0.3620, P = 0.7224). G and H Representative c-Fos staining images in the MEC (G) and dCA1 (H) of the both groups under the light ON condition. Scale bar, 50 μm. I Percentage of c-Fos positive cells in MEC layer II (left), MEC layer III (middle), and dCA1 with Wfs1+ (dCA1; right) for OptoD1-eYFP (green) or eYFP (black) groups. (n = 5, 5 mice, total 5124, 10,876 and 2684 NeuN + cells from 15 slices in OptoD1-eYFP; total 4550, 10,429 and 2437 NeuN + cells from 15 slices in eYFP) Unpaired t-test, (MECII: t8 = 2.478, P = 0.0038, MECIII: t8 = 0.3273, P = 0.7518, dCA1: t8 = 4.959, P = 0.0011). Mean ± SEM. **P < 0.01, *P < 0.05.