Chemogenetic stimulation of PPN ChAT+ neurons improved locomotor performance in a rat model of PD based on injection in SNc of the proteasomal inhibitor lastacystin, which resulted in a 48% loss of dopaminergic SNc neurons and 61% loss of PPN cholinergic neurons (Pienaar, Gartside, and others 2015; Pienaar, Harrison, and others 2015). This evidence concerns the gene CHAT and Parkinson disease.