Background
There are three kinds of allosteric modulators acting through the benzodiazepine (BZ) binding site of the GABAA receptor: positive (agonist), neutral (antagonist), and negative (inverse agonist) modulators. Agonists and inverse agonists commonly exert bidirectional influences on observed behavioral parameters. In the present study we have investigated the modulation of behavioral responses to environmental novelty in two unconditioned paradigms: spontaneous locomotor activity (SLA) and forced swim test (FST), elicited by DMCM (methyl-6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylate), a non-selective inverse agonist, in the dose range that previously did not produce anxiogenic effects and convulsions.