SNCA and Parkinson disease: Our prior publications illuminated the damage to SCs in the sural nerves of PD patients, the sciatic nerve of MPTP mice, and the vagus nerve of rats overexpressing human mutated A53T α-synuclein, manifested as SCs swelling and numerous lipid vacuoles, additionally, rats injected with AAV-A53T showed reduced intestinal blood flow and electrophysiological damage accompanied by constipation symptoms preceding the occurrence of movement disorders [9, 10, 13].