Rationale The mesolimbic dopamine system has been proved to be the key neural substrates underlying the rewarding effects of drugs of abuse.Habenula,a major relay station conveying information between the limbic forebrain and midbrain,mediates the negative feedback from forebrain dopamine-rich and limbic structures onto midbrain dopamine-secreting cells.Previous studied provided evidence that the habenula appears to be vulnerable to damage following chronic administration of most of the abused drugs.The role of the habenula in mediating the acute rewarding effects of abused drugs is unclear.Objectives The present experiments examined the effects of bilateral electric lesion of the habenula on the acquisition and maintenance of Ⅳ heroin self-administration,in order to investigate the possible role of the habenula in heroin reward.Methods:Sprague Dawley rats received bilateral electric (1.0 rnA,15 s) or sham lesions of the habenula prior to (acquisition) or after (maintenance) Ⅳ heroin self-administration training.Self-administration training was conducted under a FR1 schedule in a daily 4 h session.