Neurohistological assessment. Immunostaining of tyrosine hydroxylase-positive neurons in the SNpc and terminals in the striatum. Eight days after the final MPTP injection, all mice were subject to neurohistological assessment by immunohistochemical staining for tyrosine hydroxylase in the SNpc (bottom). Tyrosine hydroxylase-positive cells were scanned and analyzed by software; results are presented as mean±SEM. P < 0.05 was considered statistically significant.