Fig. 5.

Representative OCM images obtained from different cultures on (a) DIV 7, (b) 14, (e) 21, and (f) 28, respectively. The representative OCM images were obtained from a depth of $\sim 50\mu \mathrm{m}$ from the slice surface. (c), (d), (g), and (h) are the magnified images of the brown rectangular regions in (a), (b), (e), and (f), respectively. Viable neurons are marked as red dots. (i) Total viable neuron counts from the first $150\mu \mathrm{m}$ of the organotypic hippocampal cultures from different DIVs. ***$p<0.001$. Scale bars: $400\mu \mathrm{m}$ in (a), (b), (e), and (f), $200\mu \mathrm{m}$ in (c), (d), (g), and (h).