A direct comparison of inhalant effects on locomotor activity and schedule-controlled behavior in mice.

Increases in rates of rodent behavior have been commonly seen with exposure to abused vapors. In the 1st study, 30-min exposures to vapors of toluene, trichloroethane (TCE), or methoxyflurane produced increases in locomotor activity of mice at lower concentrations and decreases at higher concentrations. In the 2nd study, the effects of these vapors on schedule-controlled behavior were determined in mice lever pressing under a multiple fixed-ratio, 20-fixed interval (FI), 3-min schedule. Only concentration-related decreases in response rates were obtained in both components. In the 3rd study, toluene and TCE again produced only decreases in rates of responding under a simple FI 3-min schedule; biphasic effects were produced by methoxyflurane and amyl nitrite. The increases in rates of behavior often seen with abused vapors depend on the testing conditions.