Histogram of pramipexole's neuroprotective effects against MPTP induced fiber loss. Effects of subchronic treatment with pramipexole on DAT-IR (A) and TH-IR (B) optical density in the caudate-putamen, nucleus accumbens core and shell of mice treated with or without MPTP. Animals survived for 7 days after the last MPTP injection. Data are mean ± standard error of the mean from 4–5 samples per group. # for P < 0.01, all groups vs SAL + MPTP group; $ for P < 0.01, for SAL-PPX vs SAL-SAL. Abbreviations: CPU, caudate-putamen; Nac Core, nucleus accumbens core; Nac Shell, nucleus accumbens shell; PPX-MPTP, pramipexole + MPTP treated group; SAL-MPTP, saline + MPTP treated group; PPX-SAL, pramipexole + saline treated group; SAL-SAL, saline + saline treated group.