Discriminative stimulus properties of DOM and several molecular modifications

Rats trained to discriminate racemic 2,5-dimethoxy-4-methylphenylisopropylamine, (+/-)-DOM (1.0 mg/kg), from saline in a two-lever drug discrimination task were challenged with the optimal isomers of DOM as well as with several related agents which represent minor molecular modifications of the DOM structure. Generalization of the (+/-)-DOM stimulus was found to occur to R(-)-DOM, S(+)-DOM, (+/-)-2,5-dimethoxyphenylisopropylamine (2,5-DMA), R(-)-2,-5-DMA, and the 2-demethyl derivative of (+/-)-DOM. The 3-methyl positional isomer of (+/-)-DOM was found to produce only 34% DOM-appropriate responding at the highest dose tested while administration of S(+)-2,5-DMA and the 5-demethyl derivative of (+/-)-DOM resulted in disruption of behavior.