Interactions between iboga agents and methamphetamine sensitization: studies of locomotion and stereotypy in rats.
Psychopharmacology – August 01, 2000
Source: PubMed
Summary
Intriguingly, specific compounds may influence how the brain reacts to stimulants. Scientists investigated if agents, known for potentially reducing drug self-administration, affect methamphetamine's impact. They observed that pretreating rats with these compounds significantly enhanced both movement and repetitive behaviors triggered by chronic methamphetamine exposure. This consistent interaction with brain pathways involved in stimulant-driven hyperactivity supports their potential in addressing stimulant misuse.
Abstract
The phenomenon of sensitization has been theoretically implicated in mediating various aspects of drug addiction. Recent dose-response studies demonstrated that pretreatment with the putative antiaddictive agent, ibogaine (IBO), and a synthetic iboga alkaloid congener, 18-methoxycoronaridine (18-MC), increase the potency of cocaine to elicit behavioral sensitization, an effect proposed to contribute, in part, to their ability to attenuate drug self-administration. As abuse of the methylated amphetamine derivative, methamphetamine (METH), is a growing public health concern, the present study determined the interactions between IBO and 18-MC and the expression of METH-induced behavioral sensitization. The effects of pretreatment with 18-MC (40 mg/kg, IP, 19 h earlier) on the expression of METH-induced locomotion (0, 0.25, 0.5, 1 and 2 mg/kg, IP) and the effects of pretreatment with either IBO or 18-MC on the expression of METH-induced stereotypy (2 and 4 mg/kg, IP) were assessed in rats treated chronically with either METH (4 mg/kg daily for 7 days) or saline. Compared to vehicle-pretreated controls, 18-MC produced an overall enhancement in METH-induced locomotion in rats treated chronically, but not acutely, with METH. In addition, both iboga agents increased the stereotypic response to METH. Iboga agents augment both the locomotor and stereotypic effects of METH in a manner consistent with previous reports for cocaine. Thus, it appears that iboga agents interact in a similar manner with the neural mechanisms mediating motor hyperactivity induced by the chronic administration of stimulant drugs.