PRNP and Parkinson disease: To determine if Prp A53T αS Tg mice can be used as a suitable model to study constipation as it occurs in the prodromal phase of PD, we first analyzed motor deficit and correlated accumulation of αS-positive inclusions in the CNS, two typical features of this model, in young and adult presymptomatic mice, to exclude that subtle changes in the αS-driven phenotype were already present at a young age before the appearance of full-blown motor dysfunction.