Fig. 1

a Representative coronal PET/MR brain images of baseline WT/S1R-KO and blocking WT groups (n = 4 per group; blocking with BD1047 at 1 mg/kg). ctx = cortex; cp = caudate putamen; hc = hippocampus; cer = cerebellum. b Time activity curves depicting accumulation of [¹⁸F]FTC-146 in whole brain over time. We observed significantly higher brain uptake in baseline WT mice compared to S1R-KO mice at all time points during 60 min PET scan (P < 0.05). The kinetics of [¹⁸F]FTC-146 in WT blocking, S1R-KO baseline, and S1R-KO blocking studies all exhibited similar kinetics: i.e., the tracer quickly entered and cleared from the brain within 10 min post-injection