1. Dear Drugs-Forum readers: We are a small non-profit that runs one of the most read drug information & addiction help websites in the world. We serve over 4 million readers per month, and have costs like all popular websites: servers, hosting, licenses and software. To protect our independence we do not run ads. We take no government funds. We run on donations which average $25. If everyone reading this would donate $5 then this fund raiser would be done in an hour. If Drugs-Forum is useful to you, take one minute to keep it online another year by donating whatever you can today. Donations are currently not sufficient to pay our bills and keep the site up. Your help is most welcome. Thank you.
    PLEASE HELP

18-MC Acts in the Medial Habenula and Interpeduncular Nucleus to Attenuate Dopamine Sensitization to

18-MC Acts in the Medial Habenula and Interpeduncular Nucleus to Attenuate Dopamine Sensitization to

  1. Gradient
    Synapse 2007 Jul;61(7):547-6018

    Taraschenko OD, Shulan JM, Maisonneuve IM, Glick SD

    Methoxycoronaridine (18-MC), a novel iboga alkaloid congener, is a potential treatment for drug addiction. 18-MC has been shown to decrease self-administration of drugs (e.g., morphine, methamphetamine, nicotine) and attenuate opioid withdrawal in rats. In previous studies, systemic pretreatment with 18-MC abolished the sensitized increase in accumbens dopamine levels induced by chronic morphine administration. In vitro studies have shown that 18-MC is a potent antagonist of alpha3beta4 nicotinic receptors, and alpha3beta4 antagonism is believed to be the primary mechanism responsible for 18-MC's effects on drug self-administration and possibly on morphine-induced changes in mesolimbic dopamine. While there are very low densities of alpha3beta4 nicotinic receptors in the mesolimbic pathway, these receptors are prominently localized in the medial habenula (MHb) and in the interpeduncular nucleus (IPN). These nuclei and the habenulo-interpeduncular pathway connecting them are believed to function as part of an alternate reward pathway modulating the dopaminergic mesolimbic pathway known to be involved in drug addiction. In the present study, to determine if 18-MC acts in the MHb or in the IPN, the effects of local infusion of 18-MC into these brain areas were assessed on mesolimbic dopamine responses to acute and repeated morphine treatment. Administration of 18-MC (10 mug) into either the IPN or MHb blocked the sensitized dopamine response to repeated morphine in the nucleus accumbens; 18-MC had no effect on the dopamine response to acute morphine. The results suggest that 18-MC acts in the habenulo-interpeduncular pathway to modulate the effects of repeated morphine in the dopaminergic mesolimbic system.