Figure 4.

Photomicrographs depicting the effects of 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) (5 mg/kg, i.p. ×5 daily injection), on the ex‐vivo immunoreactivity of tyrosine hydroxylase (TH) in the striatum (Caudate nucleus, CA) 3 weeks after injections. Note that the MPTP treatment strikingly decreased the density of TH‐positive fibers and terminal‐like dots in the CA of the MPTP‐treated cats (right panel) as compared to control animals (treated with NaCl, left panel). Lower photomicrographs are higher power magnification of the boxed areas in upper photomicrographs. Other abbreviation: VL: lateral ventricle.