The receptor occupancy study followed very similar protocol as the PK/PD study. In addition to treatment group with compound 37 and the vehicle group, a third group of C57Bl/6 mice (n = 12, 4 at each timepoint) were dosed IV with tracer compound PGM019260 at 60 μg/kg in 10% DMSO in 0.5% 90% HP-β-CD, 20 minutes prior to the defined takedown time. Terminal tissue collection was conducted at 4, 6, and 10 hours after treatment (14 mice/timepoint). At each collection timepoint, mice were euthanized by CO2 asphyxiation and brains were extracted and dissected in cerebellum and prefrontal cortex tissue samples and placed into pre-weighed 2 ml tubes. Upon collection, all tissue samples were weighed, snap frozen in liquid nitrogen and stored at -80 °C for analysis.