Fig. 4
Bai3 overexpression in PCs induces re-innervation by CFs at distal dendrites by binding to C1ql1
A Experimental scheme. B Diagram of the functional domains of Bai3 and its mutants. C Representative CF-EPSC traces recorded from adult wild-type PCs overexpressing the indicated constructs. Paired-pulse stimulation with 50-ms interstimulus interval was applied. D The percentages of the number of CFs innervating single PCs. The number of EPSCs evoked by distinct CF activation thresholds (step numbers) is shown. Bai3-WT: p = 0.0100, n = 69 cells from 11 mice; Bai3-AAA: p = 0.0278, n = 30 cells from 4 mice; Bai3-ΔCT7: p = 0.0007, n = 60 cells from 8 mice; Bai3-S832A: p = 0.0186, n = 22 cells from 3 mice; Bai3-ΔCUB: p = 0.9981, n = 63 cells from 8 mice. Kruskal-Wallis test followed by Steel test vs. CTRL: n = 57 cells from 7 mice. E Average of the 10–90% rise time of CF-EPSCs in PCs overexpressing Bai3-WT. p = 0.0018, Two-tailed Welch’s t-test, n = 24 traces (main), n = 14 traces (surplus) from 11 mice. F Time course of CF-evoked Ca2+ changes associated with main and surplus EPSPs. Changes in the fluorescence (ΔF) were normalized by the averaged fluorescence (F0) before the CF stimulation (arrowhead). Inset, representative CF-EPSPs during Ca2+ imaging. G Representative CF-evoked Ca2+ changes associated with main and surplus EPSPs. S, PC soma. Scale bar, 20 μm. H The mean area of Ca2+ elevation associated with main or surplus CF-EPSPs. The area of large Ca2+ elevation (ΔF/F0 within 30% of the peak value) was measured. p = 2.763 × 10− 5, two-tailed Welch’s t-test, n = 7 responses (main), n = 7 (surplus) from 5 mice. I The closest distance between the site of large Ca2+ elevation and the PC soma was measured (see Methods). p = 0.0075, two-tailed Welch’s t-test, n = 7 responses (main), n = 7 (surplus) from 5 mice. Bars represent mean ± SEM. **p < 0.01; *p < 0.05; ns, not significant