Comparisons of some behavioral effects of d-amphetamine and toluene.

The levels of toluene affecting behavior were compared to those with lethal effects, for three different routes of administration. Lethality (LC50 = 13160 ppm; LD50 = 0.47 g/kg i.p., 2.25 g/kg s.c.) consistently occurred at levels 4.5-5.0 times greater than those that reduced FI 60-sec responding 50%, for all routes of administration (2700 ppm, 100 mg/kg, i.p. and 500 mg/kg, s.c.). However, inhalational exposure to toluene had effects different than those of injections of toluene with a nose-poke response. Low-to-intermediate concentrations (approximately 1000 ppm) increased responding and higher concentrations (approximately 3000 ppm) decreased responding while injections of toluene (10-300 mg/kg, i.p. and 10-3000 mg/kg, s.c.) only decreased responding. d-Amphetamine (0.3-30 mg/kg, i.p.) injections increased nose-poke responding to a lesser extent than did inhalational exposure to toluene. When a different type of response, running (one revolution around a circular runway), was maintained under an FI 60-sec schedule, toluene, d-amphetamine, and caffeine (0.3-100 mg/kg, i.p.) only decreased responding. Thus, the behavioral effects of toluene depended upon both the response studied and the route of administration, as toluene inhalation increased nose-poke responding to a greater extent than did injections of amphetamine, caffeine, or toluene. The results characterize important situational-specific factors determining the stimulant properties and behavioral toxicity of toluene which may apply to other volatile organic solvents.