Blackburn J R, Szumlinski K K
Department of Psychology, McMaster University, Hamilton, Ontario, Canada.
Behav Brain Res. 1997 Dec;89(1-2):99-106. doi: 10.1016/s0166-4328(97)00050-8.
The neural basis of ibogaine's effects on drug-related behaviours is unclear. One possibility is that ibogaine interferes with the shared capacity of many addictive agents to stimulate brain dopamine activity, but reports of ibogaine effects on dopamine activity have been inconsistent. Our study suggests such inconsistencies may result from variations in prior drug exposure. If ibogaine blocks dopamine activity, then it should, like dopamine blockers, decrease preference for natural rewards such as sweet solutions. However, 40 mg/kg ibogaine i.p. did not decrease preference for a glucose + saccharin solution when it was administered to male Long Evans rats 24 h prior to test in Experiment 1. Nor did ibogaine attenuate conditioned preference for a neutral flavour previously paired with sweet taste in Experiment 2. In Experiment 3, effects of 40 mg/kg ibogaine on amphetamine-induced locomotion were investigated in drug-naive and drug-experienced (four prior doses of 1.5 mg/kg amphetamine) rats. Locomotion was significantly lower in those ibogaine-treated rats that had previously been exposed to amphetamine than in those that had not. Thus, ibogaine may serve to decrease induced levels of dopamine activity in drug-experienced animals or humans from elevated, sensitized levels back to baseline levels. This could lead to a reduction of sensitized levels of drug craving in addiction.
伊波加因对与药物相关行为影响的神经基础尚不清楚。一种可能性是伊波加因干扰了许多成瘾物质刺激大脑多巴胺活性的共同能力，但关于伊波加因对多巴胺活性影响的报道并不一致。我们的研究表明，这种不一致可能是由于先前药物暴露的差异所致。如果伊波加因阻断多巴胺活性，那么它应该像多巴胺阻滞剂一样，降低对天然奖励（如甜味溶液）的偏好。然而，在实验1中，当在测试前24小时给雄性长 Evans 大鼠腹腔注射40mg/kg伊波加因时，并没有降低其对葡萄糖+糖精溶液的偏好。在实验2中，伊波加因也没有减弱对先前与甜味配对的中性味道的条件性偏好。在实验3中，研究了40mg/kg伊波加因对未接触过药物和有过药物经历（先前接受过四次1.5mg/kg苯丙胺注射）的大鼠苯丙胺诱导的运动的影响。先前接触过苯丙胺的伊波加因处理组大鼠的运动明显低于未接触过苯丙胺的大鼠。因此，伊波加因可能会使有药物经历的动物或人类中多巴胺活性的诱导水平从升高的、敏感化的水平降低到基线水平。这可能会导致成瘾中药物渴望的敏感化水平降低。
