In hemi-PD rats (6-OHDA + sham-BoNT-A) an ipsilateral loss of almost all TH-immunoreactivity was visible in the CPu and SN, indicating dopaminergic deafferentation in the CPu due to dopaminergic cell loss in the SN (Figure 1c,d), and BoNT-A injection in hemi-PD rats (6-OHDA + BoNT-A) did not demonstrate an additive effect on these reaction patterns (Figure 1e,f). This evidence concerns the gene TH and Parkinson disease.