This document describes various preclinical screening models used to test potential drugs for Parkinson's disease. It discusses in vivo models like antagonizing tremors induced by tremorine/oxytremorine in mice, the MPTP model in monkeys and mice, and reserpine antagonism. It also describes in vitro methods like examining dopamine-stimulated adenyl cyclase activity using rat striatal slices and studying neuroprotection in cell cultures. The screening aims to evaluate a test drug's ability to reduce Parkinson's disease-like symptoms in animal models.