Intact microdissection of stellate ganglia in a Parkinson's disease model reveals aggregation of mutant human α‐synuclein in their cell bodies

Cardiac dysautonomia plays an important role in understanding Parkinson's disease (PD), with recent studies highlighting the presence of α-synuclein in cardiac tissue. We hypothesise that sympathetic dysregulation observed in PD may involve pathological changes caused by α-synuclein in stellate ganglia (SG). This study aimed to investigate α-synucleinopathy in SG of the genetic PD murine animal model. Mice overexpressing Ala30Pro (A30P) mutant α-synuclein were used. We here demonstrate a technique for meticulously dissecting SG. The collected SG from the transgenic mice were immunolabelled with neuronal markers, A30P human mutant α-synuclein and anti-α-synuclein aggregates. A30P mutant α-synuclein protein was expressed in the sympathetic neuronal (tyrosine hydroxylase (TH)-positive) cell bodies. Approximately 27% of the TH-positive cell bodies expressed the A30P mutant α-synuclein protein. The mutant protein was densely localised at the cardiopulmonary pole of the SG. Additionally, we observed that the A30P mutant protein formed fibril aggregation in the SG. Our findings suggest that α-synucleinopathy in the PD animal model can affect the sympathetic autonomic nervous system, providing insight for further research into targeting α-synuclein pathology in the SG as a potential link between cardiac dysautonomia and PD.