Phencyclidine- and diazepam-like discriminative stimulus effects of inhalants in mice

It has been shown that abused solvents, such as 1,1,1-trichloroethane (TCE) and toluene, share certain pharmacological properties with central nervous system depressants, such as alcohol and anesthetic vapors. Several vapors were tested for diazepam (DZ)- and phencyclidine (PCP)-like discriminative stimulus effects to further explore their pharmacological specificity. In DZ-trained mice, methoxyflurane fully substituted, and TCE produced partial substitution. Fluorothyl and toluene produced no appreciable DZ-lever responding at any concentration tested. On the other hand, toluene produced concentration-related partial substitution for PCP, whereas methoxyflurane, TCE, and fluorothyl did not substitute. The substitution of some these vapors for DZ or PCP suggests that, like ethanol, the discriminative stimulus effects of abused solvents partially overlap those of N-methyl-D-aspartate antagonists as well as those of gamma amino butyric acid agonists.