Figure 5.

Effects of H₃-receptor ligands on BRET signals in cultured cortical neurons. (A) Sub-cellular localization of H₃R-YFP in rat cortical neurons, as observed by confocal microscopy two days after transfection. (A) Cortical neurons were transfected with H₃R-RLuc and H₃R-YFP or TAAR1-YFP as a control receptor in order to obtain sub-maximal BRET signals. A similar level of H₃R-YFP and TAAR1-YFP expression was ensured by fluorescence analysis. Data are the means of 6 values from two independent experiments. *** p < 0.001 versus H₃R-TAAR1 heterodimers. (B) Effects of ligands (100 nM) on H₃R dimerization were evaluated at two different BRET levels. Means ± SEM of 18–24 values from 3–4 separate experiments. Two way ANOVA was performed as follows: factor BRET F(1, 99) = 152.2, p < 0.001; factor treatment F(2, 99) = 34.8, p < 0.001; and interaction F(2, 99) = 0.196, p = 0.8. Then, the effect of ligands was evaluated in each BRET group using a non-parametric Wilcoxon/Mann–Whitney test, * p < 0.05, ** p <0.01, *** p < 0.001 versus respective control.