Fig. 4

Lactacystin-induced PPTg cholinergic lesions resemble PPN cholinergic neuronal loss seen in post-mortem human PD patients. a Stereological cell counts confirmed a decrease in interhemispheric ChAT+ cholinergic neurons of the PPTg in rats that had received an intranigral unihemispheric injection of lactacystin (L + D and L + CV, n = 12), compared to sham-lesioned rats (V + D and V + CV, n = 12). V + D vs. L + D rats, ***p <0.001; V + CV vs. L + CV, ***p <0.001. A depiction of cholinergic cell density throughout the rostro-caudal extent of the nucleus reveals that in rats that had been lesioned (L + D and L + CV), cholinergic cell density was decreased throughout the entire rostro-caudal extent of the nucleus, compared to sham-lesioned rats (V + D and V + CV), with neuronal loss noted in even the most caudal parts of the PPTg. Bars depict mean values ± SEM of cholinergic neuronal densities for b V + D compared to L + D rats and c V + CV compared to L + CV rats. d Low-magnification photomicrographs of representative PPTgs in a V + D and L + D rat illustrates how the loss of cholinergic neurons was maintained across the rostro-caudal extent of the PPTg in L + D rats. Scale bar: 200 μm