Dopaminergic neuroleptic receptors were solubilized by digitonin from post-mortem human brain putamen. The receptors were labelled by [3H]spiperone and separated from free [3H]spiperone by sephadex chromatography. Neuroleptics and neurotransmitters had similar inhibitory and stereoselective potencies on the solubilized and intact membrane receptors. The KD for [3H]spiperone was apparently high for the solubilized receptors. Unlike the rat striatum, therefore, the human putamen can be solubilized to release neuroleptic/dopamine receptors, permitting the future development of highly sensitive methods for detecting dopamine receptors.