Plasma, brain, and spinal cord levels of P7C3A20, P7C3, and Dimebon. Five mice for each compound group were treated for 21 d with 20 mg⋅kg−1⋅d−1 of the compound, starting on day 85. Blood, brain, and spinal cord were harvested 6 h after the last injection and compound levels were measured by LC/MS/MS. Concentrations are presented as mean ± SEM.