DPAI

DPAI, also known as 4-indole or as 2-desoxo-2-ene-ropinirole, is a dopamine receptor agonist and partial ergoline closely related to the clinically used dopamine receptor agonist and antiparkinsonian agent ropinirole.
It has a delayed onset of effects and weak actions in vitro, suggestive that it may be a metabolically activated prodrug via 6-hydroxylation into its metabolite 6-HO-DPAI. The drug is said to be a highly selective agonist of presynaptic dopamine autoreceptors, with little or no activity at postsynaptic dopamine receptors. It dramatically reduces dopamine release in the caudate nucleus, produces hypolocomotion, and strongly suppresses prolactin secretion in rodents.
DPAI was first described in the scientific literature by 1980. It was developed independently by David E. Nichols and colleagues and by another group of researchers.