All experimental procedures used in this study were approved by the Animal Care and Use Committee of Teijin Institute for Bio-Medical Research. All efforts were made to minimize animal suffering. All PK data were obtained using the following standardized protocol. Briefly, the species of animal was CD-1 mouse, the sex of the animals was male, and the age at start of dosing was 6 weeks. Three replicate animals were used for each experiment. Cassette dosing was used with 5 compounds per animal. Each animal was fasted from 13 h before dosing to 4 h after dosing. The compound dose for intravenous (iv) and per os (po) administration was 1 and 2 µmol/kg, respectively, and the dosing vehicle was 1/15 M NaH2PO4, 0.5% Tween 80, and 10% DMSO. Sampling time points for blood or brain were determined according to the properties of each compound and selected as 5 min, 15 min, 30 min, 1 h, 2 h, 4 h, 6 h, 8 h, or 24 h, with a sampling volume of 40 µL for plasma or whole brain. The plasma was obtained by the centrifugation of blood with anticoagulant (heparin sodium). Brain matrix was obtained by centrifugation of a homogenized sample diluted in 4-times of PBS. After deproteinization by acetonitrile, the plasma and brain sample was measured by LC-MS/MS. It should be noted that cassette dosing has a possibility of drug-drug interactions ; however, we adopted this data as long as the amount of dose is low enough 1 and 2 µmol/kg to secure the numbers of data for this study.