ADCYAP1 and Parkinson disease: PACAP has proved to be neuroprotective in different cell cultures and explant models of PD, using 6-hydroxydopamine (OHDA), 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), rotenone, salsolinol and paraquat neurotoxic agents (Takei et al., 1998; Chung et al., 2005; Wang et al., 2005; Brown et al., 2013; Lamine-Ajili et al., 2016; Hajji et al., 2019).