Abstract I-4
Neurohistochemical toxicity of Ibogaine, a proposed treatment for drug addiction
A. C. Scallet and A. Z. Xu, Experimental Neuropathology Laboratory, NTX/NCTR/FDA, Jefferson, AR-72079.

The psychoactive indole alkaloid ibogaine (IBO) has generated considerable interest as a potential therapy for chronic drug addiction. Since an original report of Ibogaine's cerebellar neurotoxicity was controversial, we aimed to replicate those observations, and extend them to IBO's time-course and dose-response. Rats (n = 6/gp) dosed with saline, or 25, 50, 75, or 100 mg/kg of IBO (IP) were perfused one week later. IBO at 100 mg/kg produced patches of Purkinje cell damage and degenerating axons, visible either with a silver stain, with Fluoro-Jade, as a local astrocytosis, or as a loss of calbindin immunoreactivity. Rats of the 75 mg/kg group were also uniformly effected, but had narrower bands of neurodegeneration, while only a subset of rats receiving 50 mg/kg had any neuropathology. The 25 mg/kg rats were not distinguishable from saline controls. These results suggest continued vigilance regarding the potential neurotoxic side effects of Ibogaine treatments in clinical settings.