Discriminative stimulus effects of glutamate release inhibitors in rats trained to discriminate ethanol

In a drug discrimination paradigm with rats trained to discriminate ethanol (1 g/kg IP) from saline we studied two substances, lamotrigine and riluzole, which are regarded as glutamate release inhibitors concerning their ability to substitute for ethanol. Both substances have been shown to act primarily on voltage-gated sodium channels; however, Lamotrigine dose dependently generalized to the ethanol cue, whereas riluzole did not. These results reflect the different high-dose effects of both sustances at voltage-gated calcium channels, where lamotrigine has inhibitory effects, but not riluzole, and provide further evidence for a role of voltage-gated calcium channels in the mediation of the effects of ethanol.