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. 2010 Dec 13;5(12):e15251. doi: 10.1371/journal.pone.0015251

Figure 2. Photomicrographs of brain sections (case R2508) immunohistochemically-stained against tyrosine hydroxylase (TH) after injections of DOPAL into the substantia nigra, pars compacta (SNpc).

Figure 2

Note the gross reduction of TH immunoreactivity in the SN at the site of injection (B; yellow arrowhead) versus the non-injected side (A). Similar loss of TH staining is seen in the striatum ipsilateral to the injection (D, arrows) versus that on the non-injected side (C, arrows), suggesting disruption of nigral dopaminergic terminals. The area just lateral to the anterior commissure (D, yellow arrowhead) however was always densely labeled (see text). Densitometry of immunostaining of striatal TH (E) showed significant differences (p<0.001) of the whole striatum contralateral and ipsilateral to DOPAL injections. Spot density measurements of ventrolateral parts of the striatum (D, red circles), however, showed an 80% loss of immunoreactivity ipsilateral to the injection. Intensely stained neurons with antibodies against tyrosine hydroxylase (F, yellow arrowheads) were sometimes seen in the SNpc of control brains surrounded by numerous neurons stained only for Nissl (F, black arrows), suggesting that counting only TH-immunostained neurons may be problematic. Abbreviations: ac, anterior commissure; SNpc, pars compacta of substantia nigra; SNpr, pars reticulata of substantia nigra. *** p<0.001.