Administration of a non-NMDA antagonist, GYKI 52466, increases excitotoxic Purkinje cell degeneration caused by ibogaine.
Neuroscience 2004 DOI: 10.1016/j.neuroscience.2004.04.058 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Experimental animal study Peer reviewed |
|---|---|
| Population | Rats |
| Interventions | Ibogaine GYKI-52466 |
| Dose | 10 mg/kg i.p. x 3 |
| Topics | Ibogaine |
| Keywords | Neurotoxicity Nerve cell damage Brain cell damage Neurodegeneration Neuronal injury Addiction treatment Substance abuse therapy Drug addiction therapy Neuroprotection Brain cell protection Protective drugs Neuroprotective agents Drug interactions Adverse drug reactions Paradoxical effects Counter-intuitive effects Brain research Neurobiology Brain chemistry Brain receptors |
| Citations | 16 |
| Key findings | Co-administration of the AMPA antagonist GYKI-52466 with ibogaine increased Purkinje cell degeneration rather than protecting against it. |
Abstract
Ibogaine is a tremorigenic hallucinogen that has been proposed for clinical use in treating addiction. We previously reported that ibogaine, administered systemically, produces degeneration of a subset of Purkinje cells in the cerebellum, primarily within the vermis. Ablation of the inferior olive affords protection against ibogaine-induced neurotoxicity leading to the interpretation that ibogaine itself is not directly toxic to Purkinje cells. We postulated that ibogaine produces sustained excitation of inferior olivary neurons that leads to excessive glutamate release at climbing fiber terminals, causing subsequent excitotoxic injury to Purkinje cells. The neuronal degeneration induced by ibogaine provides an animal model for studying excitotoxic injury in order to analyze the contribution of glutamate receptors to this injury and to evaluate neuroprotective strategies. Since non-N-methyl-D-aspartate (NMDA) receptors mediate Purkinje cell excitation by climbing fibers, we hypothesized that 1-4-aminophenyl-methyl-7,8-methylenedioxy-5H-2,3-benzodiazepine (GYKI-52466), which antagonizes non-NMDA receptors, may have a neuroprotective effect by blocking glutamatergic excitation at climbing fiber synapses. To test this hypothesis, rats were administered systemic ibogaine plus GYKI-52466 and the degree of neuronal injury was analyzed in cerebellar sections. The results indicate that the AMPA antagonist GYKI-52466 (10 mg/kg i.p. x 3) does not protect against Purkinje cell injury at the doses used. Rather, co-administration of GYKI-52466 with ibogaine produces increased toxicity evidenced by more extensive Purkinje cell degeneration. Several hypotheses that may underlie this result are discussed. Although the reason for the increased toxicity found in this study is not fully explained, the present results show that a non-NMDA antagonist can produce increased excitotoxic injury under some conditions. Therefore, caution should be exercised before employing glutamate antagonists to reduce the risk of neuronal damage in human clinical disorders. Moreover, the contribution of different glutamate receptors to excitotoxic injury is complex and merits further analysis.
Comparable studies
Other preclinical and animal studies on ibogaine, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Noncompetitive Functional Inhibition at Diverse, Human Nicotinic Acetylcholine Receptor Subtypes by Bupropion, Phencyclidine, and Ibogaine TE671/RD cells (human muscle-type nAChR) and SH-SY5Y neuroblastoma cells (human... | 1999 | In vitro study | |
| Degeneration of Purkinje cells in parasagittal zones of the cerebellar vermis after treatment with ibogaine or harmaline. Ibogaine- or harmaline-treated rats | 1993 | Experimental animal study | |
| Effects and aftereffects of ibogaine on morphine self-administration in rats. Rats | 1991 | Preclinical experimental study | |
| Effects of iboga alkaloids on morphine and cocaine self-administration in rats: relationship to tremorigenic effects and to effects on dopamine release in nucleus accumbens and striatum. Rats | 1994 | Experimental study | |
| Glial Cell Line-Derived Neurotrophic Factor Mediates the Desirable Actions of the Anti-Addiction Drug Ibogaine against Alcohol Consumption Rats | 2005 | Experimental study |
Citations in the library
Cites 9
- Degeneration of Purkinje cells in parasagittal zones of the cerebellar vermis after treatment with ibogaine or harmaline. Neuroscience July 1, 1993
- Effects and aftereffects of ibogaine on morphine self-administration in rats. European Journal of Pharmacology April 3, 1991
- Effects of iboga alkaloids on morphine and cocaine self-administration in rats: relationship to tremorigenic effects and to effects on dopamine release in nucleus accumbens and striatum. Brain Research September 19, 1994
- A preliminary investigation of ibogaine: case reports and recommendations for further study. Journal of Substance Abuse Treatment 1994
- The Olivocerebellar Projection Mediates Ibogaine-Induced Degeneration of Purkinje Cells: A Model of Indirect, Trans-Synaptic Excitotoxicity Journal of Neuroscience November 15, 1997
and 4 more in the library