Further investigations of the serotonergic properties of the ibogaine-induced discriminative stimulus.
Progress in neuro-psychopharmacology & biological psychiatry – February 01, 1999
Source: PubMed
Summary
Unraveling how ibogaine produces its distinct effects, scientists explored its interaction with specific brain receptors. They assessed various **5-HT3, 5-HT2C, and 5-HT1A receptor ligands** in rats trained to recognize ibogaine's unique cue. Positive results showed that compounds activating **5-HT2C receptors** mimicked ibogaine's effects, though this interaction wasn't essential to the full ibogaine experience. Importantly, **5-HT1A** and **5-HT3 receptor ligands** were found not to be involved in mediating ibogaine's characteristic stimulus. This clarifies which serotonin pathways are relevant to its unique profile.
Abstract
1. 5-HT3, 5-HT2C, and 5-HT1A receptor ligands were assessed in rats trained to discriminate ibogaine from water. 2. Significant ibogaine-appropriate responding was observed following treatment with the 5-HT2C agonists MK-212 (79.6%) and mCPP (76.4%). This substitution was completely antagonized by metergoline, an agent with 5-HT2C antagonist properties. However, metergoline was ineffective against ibogaine itself. This suggests that although ibogaine may act as an agonist at 5-HT2C receptors, this interaction is not essential to its discriminative cue. 3. Neither the 5-HT3 agonist, mCPBG (44.3%), nor the 5-HT3 antagonist, ondansetron (48.9%) substituted for ibogaine. Likewise, the 5-HT1A agonist 8-OH-DPAT (34.7%) and the 5-HT1A antagonist WAY-100635 (30.1%) failed to substitute. Furthermore, WAY-100635 failed to antagonize the ibogaine cue. 4. Unlike 5-HT2C receptors, 5-HT1A and 5-HT3 receptors do not appear to be involved in the ibogaine stimulus.