Researchers Identify Gene Linked to Heroin Relapse

The threat of relapse hangs over any attempt to kick a heroin addiction. The results of a new study provide new clues as to which drug users may be at greater risk of sabotaging their treatment efforts. Scientists have identified a gene that plays a crucial role in controlling heroin craving and relapse behavior in rodents.
The nucleus accumbens is a brain region important for processing pleasure and rewards; as such, it is central to heroin addiction. Using the drug activates the area, which is divided into a core and a shell, to produce effects that are both pleasurable and highly addictive. Ivan Diamond of the Ernest Gallo Clinic and Research Center in Emeryville, Calif., and his colleagues studied rats that ingested repeated doses of heroin and found that a gene known as AGS3 can increase the output of the signaling in some neurons that respond to the drug. When the researchers inhibited the expression of AGS3 in the nucleus accumbens core of animals that had previously experienced both addiction and withdrawal, they found that the rats showed less desire to seek out additional drugs after they were given a small dose. Interfering AGS3 expression in the shell of the nucleus accumbens did not dampen their desire for the drug, however.

The results build on work that previously implicated AGS3 in cocaine relapse as well. "These observations," the authors conclude, "open an avenue to develop treatments for heroin addiction directed against relapse." A report detailing the findings will be published online this week by the Proceedings of the National Academy of Sciences. --Sarah Graham

    據(jù)sciam5月31日?qǐng)?bào)道,，長(zhǎng)久以來(lái)人們一直嘗試著防止吸毒者藥物戒毒后復(fù)吸,?？茖W(xué)家已經(jīng)在嚙齒類動(dòng)物體內(nèi)鑒別出一個(gè)在控制海洛因成癮和復(fù)吸行為上起著關(guān)鍵性作用的基因。對(duì)于將海洛因作為藥物來(lái)使用的患者來(lái)說,，更高的成癮危險(xiǎn)性可能會(huì)影響其治療效果,。美國(guó)最新的研究結(jié)果為這種情況提供了種新的解決方案。

    阿肯伯氏核（nucleus accumbens）位于大腦的中心區(qū)域負(fù)責(zé)處理快樂和獎(jiǎng)賞等行為,，對(duì)海洛因的成癮也起著關(guān)鍵的作用,。該區(qū)域分為核區(qū)和外殼區(qū)，藥物激活該區(qū)域后產(chǎn)生快樂和很高的上癮性作用,。美國(guó)加利福尼亞州Emeryville的Ernest Gallo臨床和研究中心的Ivan Diamond及其同事研究了重復(fù)給海洛因后的老鼠，發(fā)現(xiàn)在一些與藥物應(yīng)答相關(guān)的神經(jīng)區(qū)中,，名為“AGS3”的基因輸出的信號(hào)增加了,。當(dāng)研究者抑制了那些上癮后停止服藥的小鼠腦部阿肯伯氏核區(qū)AGS3的表達(dá)，發(fā)現(xiàn)它們對(duì)于藥物的成癮性減少了,。但是,，如果抑制阿肯伯氏核外殼區(qū)AGS3的表達(dá)，對(duì)藥物的成癮性將不起作用,。

    此項(xiàng)研究結(jié)果是基于以前發(fā)現(xiàn)的AGS3基因?qū)Х纫虺砂a作用研究之上的,。研究者表示此項(xiàng)研究的詳細(xì)結(jié)果將于近期發(fā)表在英國(guó)《自然》雜志的電子版上，該項(xiàng)研究為開發(fā)海洛因戒癮后復(fù)吸的治療提供了新的研究方法,。