The brain:perfusate ratio of [3H]-digoxin was significantly reduced in Cu(ATSM) treated mice indicating enhanced P-gp mediated efflux capacity, and this ratio was comparable (~0.002–0.003 mL/g) to ratios found in other studies in our laboratory that used a 150-day old mouse model of amyotrophic lateral sclerosis [78]. Here, PGP is linked to amyotrophic lateral sclerosis.