Acute and prolonged effects of ibogaine on brain dopamine metabolism and morphine-induced locomotor activity in rats.
Brain research – March 13, 1992
Source: PubMed
Summary
Ibogaine significantly impacts dopamine levels, showing a 50% decrease in dopamine one hour post-administration in key brain regions. This was accompanied by a 37-100% increase in homovanillic acid. Nineteen hours later, reductions in dopamine metabolites were noted, with striatal levels remaining low even after a week. Additionally, ibogaine pretreatment diminished morphine-induced locomotion across various doses, illustrating its potential to modulate addiction-related behaviors. By one month, neurochemical changes and locomotor effects returned to baseline levels, indicating temporary alterations.
Abstract
Ibogaine, an indolalkylamine, proposed for use in treating opiate and stimulant addiction, has been shown to modulate the dopaminergic system acutely and one day later. In the present study we sought to systematically determine the effects of ibogaine on the levels of dopamine (DA) and the dopamine metabolites 3,4 dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in tissue at several time points, between 1 h and 1 month post-injection. One hour after ibogaine-administration (40 mg/kg i.p.) a 50% decrease in DA along with a 37-100% increase in HVA were observed in all 3 brain regions studied: striatum, nucleus accumbens and prefrontal cortex. Nineteen hours after ibogaine-administration a decrease in DOPAC was seen in the nucleus accumbens and in the striatum. A week after administration of ibogaine striatal DOPAC levels were still reduced. A month after ibogaine injection there were no significant neurochemical changes in any region. We also investigated the effects of ibogaine pretreatment on morphine-induced locomotor activity, which is thought to depend on DA release. Using photocell activity cages we found that ibogaine pretreatment decreased the stimulatory motor effects induced by a wide range of morphine doses (0.5-20 mg/kg, i.p.) administered 19 h later; a similar effect was observed when morphine (5 mg/kg) was administered a week after ibogaine pretreatment. No significant changes in morphine-induced locomotion were seen a month after ibogaine pretreatment. The present findings indicate that ibogaine produces both acute and delayed effects on the tissue content of DA and its metabolites, and these changes coincide with a sustained depression of morphine-induced locomotor activity.