Disrupted spontaneous alternation in the T-maze test and impaired performance in the RAM suggest the late-stage development of working memory deficits, similar to that observed in PDD [42] This disruption in reference and working memory performance was accompanied by the appearance of proteinase K-resistant synuclein aggregates in the hippocampus and cortex, along with reductions in synaptophysin density, suggesting a regional progression of pathology, similar to that reported in PD patients [32, 43]. Here, SYP is linked to Parkinson disease.