IBOGAINE NEUROTOXICITY - A REEVALUATION

Ibogaine is claimed to be an effective treatment for opiate and stimul ant addiction. O'Hearn and Molliver, however, showed that ibogaine cau ses degeneration of cerebellar Purkinje cells in rats. The present stu dy re-examined cerebellar responses to the high doses of ibogaine used by O'Hearn and Molliver (100 mg/kg or 3 x 100 mg/kg) and sought to de termine whether a lower dose (40 mg/kg), one effective in reducing mor phine and cocaine self-administration, produced similar responses. Pur kinje cell degeneration was evaluated with a Fink-Heimer II stain, and enhanced glial cell activity with an antibody to glial fibrillary aci dic protein. Every rat treated with the high dose of ibogaine displaye d clear evidence of Purkinje cell degeneration. The degeneration consi stently occurred in the intermediate and lateral cerebellum, as well a s the vermis. Purkinje cells in lobules 5 and 6 were particularly susc eptible. Given the response properties of cells in these lobules, this finding suggests any long-term motor deficits produced by ibogaine-in duced degeneration should preferentially affect the head and upper ext remity. In marked contrast, rats given the smaller dose of ibogaine di splayed no degeneration above the level seen in saline-treated animals . When combined with information on other compounds, these data sugges t that the degenerative and 'anti-addictive' properties of ibogaine re flect different actions of the drug.