Figure 7.

Quantification of the dendritic elaboration of spiny layer 4 pyramidal and stellate neurons in ferret A17 during postnatal development. A–F, Measurements of dendritic span (A, B), total length (C, D), and number of branch points (E, F) in apical dendrite (A, C, E) and basal dendritic (B, D, F) arbor of pyramidal and stellate neurons between P14 and P40. Data are mean ± SEM; *p < 0.05, **p < 0.01, ***p < 0.001, t test after two-way ANOVA for multiple comparisons (p < 0.05). G, H, Analysis of DGI of apical dendrite (G) and basal dendritic (H) arbor of layer 4 pyramidal and stellate neurons between P14 and P40. DGI is calculated with respect to P14 for each group independently. Black curves are trend lines (third-order polynomial) for DGI data of pyramids (r² = 0.94) and stellates (r² = 0.73). Pyramids, n = 27 neurons at P14; 25 at P18; 32 at P22; 15 at P26; 21 at P30; 13 at P35; 4 at P40. Stellates, n = 2 neurons at P18; 9 at P22; 18 at P26; 54 at P30; 14 at P35; 9 at P40.