Altered function and maturation of primary cortical neurons from a 22q11.2 deletion mouse model of schizophrenia

Fig. 1. Passive membrane properties of WT and Df(16)A+/− cortical neurons. a Bright field images of WT and Df(16)A+/− cortical neurons co-cultured with astrocytes at DIV7 and DIV14. Scale bar = 50 µm. b Quantitative data of resting membrane potential (RMP) measured in WT and Df(16)A+/− cortical neurons at DIV7 and DIV14, respectively. There was no significant difference between genotypes at both time points. c Quantitative data of cell capacitance (Cp) in WT and Df(16)A+/− cortical neurons at DIV7 and DIV14, respectively. There was no significant difference between genotypes at both time points. d Quantitative data of input resistance (Rin) in WT and Df(16)A+/− cortical neurons at DIV7 and DIV14, respectively. Df(16)A+/− cortical neurons showed significant higher Rin than that of WT neurons at DIV7 (t test, *p < 0.05). e Quantitative data of voltage sags caused by HCN-mediated currents in WT and Df(16)A+/− cortical neurons at DIV7 and DIV14, respectively. There was no significant difference between genotypes at both time points. f Sample traces of HCN-caused voltage sags in WT and Df(16)A+/− cortical neurons at DIV7. In the presence of HCN-mediated currents, a negative current step…

Fig. 2. Action potential properties and cell excitability of WT and Df(16)A+/− cortical neurons. a Representative action potential trains in WT (left panel) and Df(16)A+/− neurons (middle panel) at DIV7 (upper panel) and DIV14 (lower panel), in response to a 500 ms depolarizing 100 pA current step from −60 mV. A close up of the WT (blue trace) vs. Df(16)A+/− neuron (red trace) action potential waveforms overlaid (right panel) at both DIV7 and DIV14. b Quantitative data of overshoot (AP amplitude) in WT and Df(16)A+/− cortical neurons at DIV7 and DIV14, respectively. Df(16)A+/− cortical neurons showed significant decrease in overshoot at DIV7 compared to WT neurons (t test, *p < 0.05). c Quantitative data of half width (AP duration) in WT and Df(16)A+/− cortical neurons at DIV7 and DIV14, respectively. There was no significant difference between genotypes at both time points. (d) Quantitative data of rising rate in WT and Df(16)A+/− cortical neurons at DIV7 and DIV14, respectively. Df(16)A+/− cortical neurons showed significant decrease in rising rate at DIV7 compared to WT neurons (t test, * p < 0.05). e Quantitative data of decay rate in WT and Df(16)A+/− cortical neurons at DIV7 and…

Fig. 3. Synaptic properties of WT and Df(16)A+/− cortical neurons. a Sample traces of sEPSCs from WT (blue trace) and Df(16)A+/− (red trace) neurons at DIV7 (upper panel) and DIV14 (lower panel), respectively. Scale bar as shown in inset. b Sample traces of mEPSCs from WT (blue trace) and Df(16)A+/− (red trace) neurons at DIV7 (upper panel) and DIV14 (lower panel), respectively. Scale bar as shown in inset. c Bar graphs of sEPSCs of WT and Df(16)A+/− cortical neurons at DIV7 and DIV14. No significant difference was observed between genotypes. d Bar graphs of mEPSCs of WT and Df(16)A+/− cortical neurons at DIV7 and DIV14. No significant difference was observed between genotypes. e Sample traces of sIPSCs from WT (blue trace) and Df(16)A+/− (red trace) neurons at DIV7 (upper panel) and DIV14 (lower panel), respectively. Scale bar as shown in inset. f Sample traces of mIPSCs from WT (blue trace) and Df(16)A+/− (red trace) neurons at DIV7 (upper panel) and DIV14 (lower panel), respectively. Scale bar as shown in inset. g Bar graphs of sIPSCs of WT and Df(16)A+/− cortical neurons at DIV7 and DIV14. Df(16)A+/− cortical neurons showed significant increase in frequency at DIV7 compared to WT…

Fig. 4. Calcium imaging of WT and Df(16)A+/− cortical neurons. a Graph shows voltage-gated calcium responses in WT (open circles) and Df(16)A+/− (closed circles) cortical neurons at DIV7 by exposing to 30 mM KCl for 2 s (top panel), 5 s (middle panel), and 10 s (bottom panel). b Graph shows voltage-gated calcium responses in WT (open circles) and Df(16)A+/− (closed circles) cortical neurons at DIV14 by exposing to 30 mM KCl for 2 s (top panel), 5 s (middle panel), and 10 s (bottom panel). Neurons were loaded with Fura-2. Data were plotted as the ratio of fluorescence intensity excited at 340 and 380 nm vs. time and the values were normalized to the averaged baseline level. c Summary data of calcium imaging for WT and Df(16)A+/− cortical neurons at DIV7. Compared to WT neurons, Df(16)A+/− neuros showed significantly lower peak value of calcium elevation at 2 s and smaller AUC under all treatments. d Summary data of calcium imaging for WT and Df(16)A+/− cortical neurons at DIV14. Significantly decreased basal calcium level, lower peak values, smaller AUC, and faster recovery were observed for Df(16)A+/− neurons compared to WT ones

Fig. 5. Gene expression profile analysis of WT and Df(16)A+/− cortical neurons. a PCA analysis indicates a good separation of the expression profiles between WT (green) and Df(16)A+/− (red) cortical neurons at DIV7. b Volcano plot indicating downregulation of the genes within the 22q11.2 deletion region and upregulation of primary miRNA genes and Mirta22/Emc10 as previous reported. c GO and phenotype analysis of significantly upregulated genes (FDR adjusted p < 0.05). d GO and phenotype analysis of significantly downregulated genes (FDR adjusted p < 0.05)