NPHS1 and supranuclear palsy, progressive, 1: Notably, whereas earlier studies highlighted the loss of cholinergic neurons within the PPN in PD or PSP patients as evidence of their involvement in dopamine-resistant signs such as FOG (Hirsch et al., 1987; Jellinger, 1988; Zweig et al., 1989), newer studies reveal that noncholinergic neurons in both the PPN and CnF also show significant degeneration in PD and PSP (Pienaar et al., 2013; Sebille et al., 2019).