Figure 3.

Corticosterone increases GluA1 mobility within spines. A, Schematic of experimental design: FRAP performed on same cohort of mice across three separate days to obtain baseline and measurements at 1, 2, and 3 h postinjection of saline and corticosterone. B, Representative MIP image of L2/3 visual cortex neurons expressing DsRed cell fill (magenta), SEP-GluA1 (green), and myc-GluA2 3 h postinjection of saline. Scale bar: 10 μm. Area of interest indicated corresponding to panel C. C, Representative MIP image of bleached (bracket) and unbleached (arrow) spines and fluorescence recovery. Scale bar: 2 μm. See also Extended Data Figure 3-1. D, Fluorescence recovery of SEP-GluA1 in spines at baseline (n = 106 spines) and at 1 h (n = 45 spines), 2 h (n = 51 spines), and 3 h (n = 53 spines) postinjection of saline (multifactorial ANOVA; Extended Data Figures 3-3, 3-4). Time points were fitted with an exponential curve indicated by solid line with 95% CI in shaded area. E, Comparison of mobile fraction at baseline and indicated times postinjection of saline defined by maximum fluorescence recovery calculated as Ymax of fitted exponential curves displayed in panel D (one-way ANOVA; Extended Data Figure 3-5). F, G, Similar to D, E at baseline and 1 h (n = 43 spines), 2 h (n = 55 spines), and 3 h (n = 51 spines) postinjection of corticosterone [Cort; multifactorial ANOVA for F (Extended Data Figure 3-6), one-way ANOVA with Sidak’s multiple comparison tests for G (Extended Data Figure 3-7)]. H, Comparison of fluorescence recovery at times postinjection of corticosterone versus saline (two-way ANOVA with Sidak’s multiple comparison test; Extended Data Figure 3-8). I, Comparison of spine enrichment at 3 h postinjection (t test, p =0.43). J, Comparison of spine DsRed intensity normalized to nearby dendritic shaft DsRed intensity at 3 h postinjection (t test, p = 0.98). D–J, n = 5 mice, error bars indicate SEM, ****p < 0.0001, ***p < 0.001, *p < 0.05, ns = not significant. See also Extended Data Figure 3-2.