Intravenous self-administration of abused solvents and anesthetics in mice

Volatile organic solvents, fuels and anesthetics are subject to abuse. The aim of the present study was to evaluate i.v. self-administration of several of these chemicals in drug- and experiment-naive mice using a commercially available vehicle, intralipid. Two strains of mice (DBA/ 2 and Swiss) were allowed to self-administer toluene (0.0017-0.17 lunol/infusion), 1,1,1-trichloroethane (0.006-0.19 mumol/infusion), ethanol (0.32-1.6 mumol/infusion), cyclohexane (0.0017-0.052 mumol/infusion), propofol (0.01 -0.53 mumol/infusion) and flurothyl (0.00042-0.072 mumol/infusion) or their vehicles during 30-min tests. During the test, each nose-poke of the master mouse resulted in a 1.88-mul i.v. infusion to the master mouse and a yoked control mouse. When the delivery line was loaded with a reinforcing drug solution, the number of nose-pokes of the master mice significantly exceeded that for yoked control mice. In the present experiments, significant differences in rates of nose-poking were observed between mice receiving response-contingent and response-noncontingent deliveries of ethanol and toluene in both strains of mice and of 1,1,1-trichloroethane in Swiss mice. These data suggest that the reinforcing effects of abused inhalants can be studied using i.v. self-administration procedures. (C) 2003 Published by Elsevier B.V.