In the present study, after the dopaminergic neurons in the SN are destroyed by the 6-OHDA, the expressions of both D1 and OXA in the LH, and OX1R and ChAT in the DMV were significantly decrease, suggesting that the excitatory effect from the SN on OXA-positive neurons of the LH and in turn on the vagal cholinergic motor neurons of the DMV would be lowered, which subsequently resulted to gastroparesis in 6-OHDA rats. This evidence concerns the gene CHAT and gastroparesis.