The voluntary inhalation of organic solvents and other vaolatile chemicals remains a significant public health problem. Very little is known concerning the type of intoxication produced by these chemicals and whether or not the effects of all abused inhalants are similar. The hypothesis to be evaluated in this proposed research is that some of the inhaled solvents produce acute intoxications similar to those produced by central nervous system depressants such as alcohol and the barbiturates and/or volatile anesthetics such as halothane. Studies of the discriminative stimulus properties of abused solvents in mice will be used as the model for acute intoxication effects. The following questions will be addressed. Do the abused inhalants toluene, 1,1,1-trichloroethane, and isobutyl nitrite produce discriminative stimulus effects similar to pentobarbital, ethanol, and/or halothane which may explain their self-administration? Do all abused solvents and inhaled compounds have similar acute discriminative stimulus effects? What are the relative potencies of abused inhalants? Does administration of solvents by injection and by inhalation result in different effects? What are the important exposure parameters determining solvent effects by inhalation? What methodologies are most appropriate for studying the acute behavioral effects of inhaled compounds in the laboratory. Answers to these questions will significantly help our understanding of the solvent abuse phenomenon, and may lead to altered prevention and treatment strategies. Also, comparisons of various solvents will help identify those with significant abuse potential. Finally, the discovery of commonalities in the effects of abused solvents, alcohol, anesthetics, and classical CNS depressants such as the barbiturates will have implications for theories on the neurobiology of the abuse of depressant drugs and specifically on theories for the cellular mechanisms of action for these compounds. Because abused solvents share properties with both alcohol and abused depressant drugs, studies of solvents may provide a basis for bringing together the research on substance abuse.