Figure 3.

Region of interest (ROI)-based analyses of (A)binding potential ratios (BPR) and (B) histamine H₁ receptor occupancy (H₁RO) in the cortex. ROI measurements were taken in the medial prefrontal (MPFC), dorsolateral prefrontal (DLPFC), anterior cingulate (AC), insular (IC), temporal (TC), parietal (PC), occipital cortex (OC) after treatment with antihistamines. Comparison of BPRs shows differences in the sedative properties of the three drugs such as placebo (PLA), olopatadine (OLO) and ketotifen (KET) (A). H₁RO by the two antihistamines are shown taking H₁RO by the placebo as 0% (B). P < 0.001, statistically examined by anova followed by multiple comparison by Bonferroni test. The error bars represent interindividual variability (SD). PLA (□); OLO (▪); KET (▪)