Fig. 8

CA3 pyramidal neuronal activity regulates adult hippocampal neurogenesis. a Schematic representation of the experimental design. One week after stereotaxic injection of AAV-hM3Dq or AAV-hM4Di into the CA3 region, mice were injected six times intraperitoneally with BrdU (50 mg/kg) at 12 h intervals. After daily intraperitoneal injection of CNO (10 mg/kg) for 2 weeks, mice were killed and BrdU incorporation was measured. b Representative micrographs showing the expression of (left panel) hM3Dq and (right panel) hM4Di receptors in the hippocampal CA3 region (counterstained with DAPI, blue). Scale bar: 500 μm. c Representative traces showing responses of uninfected (control) and infected (hM3Dq⁺ or hM4Di⁺) neurons to depolarizing current ( + 150 pA, 500 ms) or hyperpolarizing current pulse (−50 pA, 500 ms) under whole-cell current-clamp before and after bath application of CNO (1 μM) in the ex vivo hippocampal slices. d Representative immunofluorescence images of hippocampal sections from WT, Oxtr ^−/−, WT + hM4Di and Oxtr ^−/− + hM3Dq stained for BrdU (green) at 14 days after the last BrdU injection (counterstained with NeuN, red). Scale bar, 100 µm. e Quantification of the total number of BrdU⁺ cells in the dentate gyrus of WT, Oxtr ^−/−, WT + hM4Di and Oxtr ^−/− + hM3Dq mice at 14 days after BrdU injection (WT, n = 7 mice; Oxtr ^−/− , n = 9 mice; WT + hM4Di, n = 7 mice; Oxtr ^−/−  + hM3Dq, n = 5 mice; *P < 0.05, **P < 0.01, and ***P < 0.001, unpaired two-tailed Student’s t test). Data represent the mean ± s.e.m