Figure 1. Assessment of the dopaminergic lesion induced by 6-OHDA injection in the medial forebrain bundle.

(a) Transverse section taken through the substantia nigra pars compacta (SNc) and the ventral tegmental area (VTA) that was immunostained for tyrosine hydroxylase (TH) to assess the dopaminergic lesion induced by stereotaxic injection of 6-OHDA in the right medial forebrain bundle. (b) Histogram showing the percentage of TH + cell loss in the SNc and the VTA, as expressed in percentage of intact side. (c) Transverse section taken through the striatum (STR) and immunostained for TH. (d) Histogram showing immunoreactivity of the STR and the nucleus accumbens (Acb) for the tyrosine hydroxylase (TH) and the dopamine transporter (DAT) in the 6-OHDA-lesioned side, as expressed in percentage of intact side. (e) Behavioural response induced by 6-OHDA lesion, as shown in number of contralateral and ipsilateral spontaneous rotations observed in 10 minutes. *P < 0.05, **P < 0.01, ***P < 0.001 for intact side vs. 6-OHDA-lesioned side, ****P < 0.0001 for ipsilateral vs. contralateral rotations, by Mann-Whitney test.