• Parkinson disease;
  • α-synuclein;
  • dopamine transporter;
  • striatum;
  • brain imaging


Aggregated α-synuclein is the hallmark of Parkinson's disease (PD), diffuse Lewy body disease (DLBD), and multiple system atrophy (MSA). Physiologically, α-synuclein ensures normal functions of dopamine transporter (DAT) and tyrosine hydoxylase. In α-synucleinopathies, it accumulates in neuronal cytoplasm and neurites through several stages. It is unclear whether the accumulation of pathological α-synuclein in the substantia nigra in PD correlates with the dopaminergic deficit in the striatal target. We evaluated the impact of the nigral burden of pathological α-synuclein immunoreactivity in 27 α-synucleinopathy brains by morphometric immunohistochemistry. DAT immunoreactivity in the striatum inversely correlates with the total α-synuclein burden in the substantia nigra but not with cytoplasmic inclusion counts only. This result has implications for imaging, clinicopathological correlative studies, and staging of the disease process. © 2008 Movement Disorder Society