Fig. 6
TGB attenuates aberrant gamma power and levels of GABAARs. a Diagram illustrating simultaneous in vivo microinjection and LFP recording in the OB. b-c Representative traces and quantification of gamma oscillations in APP/PS1 OB before (baseline) and after microinjection of GBZ at 500 μM. GBZ injection has no significant effect on gamma power (n = 5 mice, p = 0.33, paired sample t-test). d Representative traces of gamma oscillation in WT and APP/PS1 before and after microinjection of TGB. e Increased gamma oscillatory power in APP/PS1 OB is ameliorated after acute TGB microinjection compared to baseline (n = 9 for WT and n = 6 for APP/PS1, p = 0.002 for WT vs APP/PS1; p = 0.02 for APP/PS1 baseline vs APP/PS1 + TGB; p = 0.06 for WT + TGB vs APP/PS1 + TGB, two-way ANOVA with Bonferroni’s post-hoc test). f-g Representative immunoblots and quantification of GABAAR α1, β3 subunits and GluR1 in the OB of TGB- and vehicle-treated mice. TGB significantly reduced levels of GABAAR α1 and β3 subunits (n = 5–8 mice/group, GABAAR β3: p = 0.03 for WT vs APP/PS1; p = 0.009 for APP/PS1 vs APP/PS1 + TGB; GABAAR α1: p = 0.001 for WT vs APP/PS1; p = 0.0002 for APP/PS1 vs APP/PS1 + TGB, two-sample t-test). h One-week TGB did not improve olfactory behavior in APP/PS1 mice (n = 7–9 mice/group; p = 0.0002 for WT + PBS vs APP/PS1 + PBS; p = 0.037 for WT + TGB vs APP/PS1 + TGB; p = 0.52 for APP/PS1 + PBS vs APP/PS1 + TGB, two-sample t-test). Values represent mean ± SEM. *p < 0.05; **p < 0.01; ***p < 0.001