Figure 3.

ROI-based analyses of BPs and H₁-receptor occupancies in the cortex, anterior cingulate cortex (ACC) and thalamus (Th) after antihistamine treatments. (a) In study 1, the comparisons of BPs are shown among the control (), ebastine (▪) and (+)-chlorpheniramine 2 mg () groups. In study 2, the BP values are compared between the placebo () and (+)-chlorpheniramine 6 mg () treatment groups. (b) H₁-receptor occupancies by antihistamines (ebastine ▪; (+)-chlorpheniramine 2 mg ; and (+)-chlorpheniramine 6 mg ) are shown when the occupancy in the control or placebo group is regarded as 0%. *P< 0.01 and **P< 0.001, statistically analysed by Dunnett's multiple comparison test or by Student's t-test.