THE EFFECTS OF NORIBOGAINE AND HARMALINE IN RATS TRAINED WITH IBOGAINE AS A DISCRIMINATIVE STIMULUS

In the present investigation, Fischer-344 rats were trained to discrim inate 10.0 mg/kg of ibogaine from water using a pretreatment time of 6 0 minutes. Analysis of dose response data generated an ED(50) of 4.6 m g/kg. The time course of the ibogaine (10.0 mg/kg) cue was also determ ined. The stimulus reached a maximum level of 94% ibogaine-appropriate responding at the 60-min pretreatment time. This was followed by a ti me-dependent decrease in ibogaine-appropriate responding. At a pretrea tment time of 8 hrs only 6.4% drug-appropriate responding was observed . In substitution experiments, intermediate generalization was observe d with a metabolite of ibogaine, 12-hydroxyibogamine [noribogaine] (71 .6%) whereas complete generalization was seen with harmaline (83.5%).