Some effects of sub-acute exposure to toluene on schedule-controlled behavior

Behavioral effects of repeated exposure to toluene have been assessed on mice responding under an FI 60-sec schedule of milk presentation in a hermetically sealed chamber. Sessions consisted of alternating 10 min periods where milk was available under the FI schedule and 25 min periods where responding had no scheduled consequences. Mice were exposed to 500, 1000 or 2000 ppm toluene, for the last 4 hrs of five consecutive daily sessions. At concentrations of 500 ppm toluene had little effect on responding, on any of the 5 days of repeated exposure. Concentrations of 1000 ppm consistently increased rates of responding during each session and each day of repeated exposure. Concentrations of 2000 ppm consistently decreased responding after the first exposure series during daily exposures; increases in responding were seen at the beginning of sessions during the initial days of exposure. Consistent concentration-dependent effects of toluene were obtained over 4-hr exposure periods with schedule-controlled responding in mice.