Immunotoxin cell targeting is a transgenic technology to eliminate specific cell types from a complex neural circuitry by using the cytotoxic activity of recombinant immunotoxins. This technology provides a useful approach for understanding the neural mechanism underlying a variety of brain functions. The present update article describes recent applications of the technology for the study of basal ganglia circuitry that mediates motor behavior related to dopamine transmission. In particular, the article proposes a possible model in which dopamine coordinates motor behavior through different neural pathways of basal ganglia circuitry.