Toluene, halothane, 1,1,1-trichloroethane and oxazepam produce ethanol-like discriminative stimulus effects in mice

Drug discrimination procedures were used to compare the discriminative stimulus properties of ETOH and volatile inhalants. Mice were trained to discriminate between i.p. injections of ETOH (1 g/kg) and saline in a two-lever operant task. Stimulus generalization was examined after 20-min inhalation exposures to toluene (300-5400 ppm), halothane (500-8000 ppm) and 1,1,1,-trichloroethane (TCE; 125-14000 ppm). Oxazepam (10-30 mg/kg i.p.) also was tested. Concentration- or dose-related increases in ETOH-lever responding were observed with toluene, halothane, TCE and oxazepam. Shared discriminative stimulus properties among toluene, halothane, TCE and ETOH indicate that some volatile inhalants share pharmacological properties with ETOH. Previous research has shown that these inhalants also produce pentobarbital-like discriminative stimulus effects in mice. Thus, at least some inhaled anesthetics and abused solvents have behavioral effects in common with abused central nervous system depressant drugs such as ETOH and barbiturates.