Figure 6|. Chronic microglial β₂AR activation impairs adolescent ocular dominance plasticity.

(a) Schematic of the intrinsic optical signal imaging. (b) Representative amplitude maps from stimulation of the ipsilateral (top) and contralateral (bottom) eyes for mice treated with saline (S), nadolol/clenbuterol (NC), and DSP4. Non-deprived (ND) maps are shown for S treatment. All other maps are after 4 days of monocular deprivation (4MD), these maps are representative of the presented findings. (c) Quantification of the ocular dominance index (ODI) demonstrates ocular dominance shifts with S and nadolol (N) treatment, but no shifts with NC and DSP4 treatment (n: S ND=15, S 4MD=14, N ND=6, N 4MD=6, NC ND=6, NC 4MD=11, DSP4 ND=6, DSP4 4MD=8 mice, two-way ANOVA, main effects of MD (p=0.00033, F(1,76)=14.15), and treatment (p=0.0025, F(4,76)=4.51), and interaction (p=0.00035, F(4,76)=5.89). Holm-Sidak multiple comparisons: S 4MD v. NC 4MD p=0.00014, S 4MD v. DSP4 4MD, p=1.0×10⁻⁵). (d) Example imaging of a single dendrite (magenta) and microglial process (green) across 35 minutes showing numerous putative microglia dendritic spine interactions (white arrowheads). (e) NC treatment reduces the proportion of dendritic spines contacted by microglial processes over one hour (n: S=7, N=3, NC=5, DSP4=4 mice, one-way ANOVA, p=0.022, F(3,15)=4.35, Holm-Sidak multiple comparisons: S v. NC p=0.041, N v. NC, p=0.061). Scale bar = 5μm. Graphs show mean±SEM. Abbreviations: S=saline, N=nadolol, NC=nadolol/clenbuterol, ICI=ICI-118,551, DSP4= N-(2-Chloroethyl)-N-ethyl-2-bromobenzylamine; ND=non-deprived, 4MD=4 days monocular deprivation; *p<0.05, **p<0.01, ***p<0.005. Points represent individual animals. See Supplementary Table 1 for the number of females and males used in these experiments.