美國加州大學(xué)歐文分校研究人員最新發(fā)現(xiàn)，阻斷動(dòng)物體內(nèi)一種特定的激素作用,，可以抑制對(duì)可卡因的渴望,。這一新發(fā)現(xiàn)將有助于開發(fā)出戒除毒癮的新方法。
研究小組在新一期美國《國家科學(xué)院院刊》（PNAS）上報(bào)告說,，他們以老鼠為實(shí)驗(yàn)對(duì)象發(fā)現(xiàn),，服用可卡因后，在大腦控制產(chǎn)生快感的“愉快中樞”內(nèi),，一種黑色素聚集激素（MCH）對(duì)多巴胺具有調(diào)節(jié)作用,，從而使大腦產(chǎn)生對(duì)可卡因的上癮響應(yīng)。
多巴胺是一種神經(jīng)遞質(zhì),，對(duì)中樞神經(jīng)系統(tǒng)的正常工作至關(guān)重要,。大腦產(chǎn)生愉快感時(shí)，就會(huì)釋放多巴胺,。此前研究曾發(fā)現(xiàn),，有毒癮者大腦中“愉快中樞”區(qū)域的多巴胺水平明顯高于常人。
新研究發(fā)現(xiàn),，成癮過程中,，MCH和多巴胺的水平同時(shí)升高,。如果阻斷實(shí)驗(yàn)鼠大腦內(nèi)MCH的活動(dòng)，就可以抑制機(jī)體對(duì)可卡因的渴望,，實(shí)驗(yàn)鼠表現(xiàn)出的可卡因癮性明顯減小,。
研究人員說，這表明在大腦產(chǎn)生愉快感及成癮過程中,，MCH是多巴胺的一個(gè)關(guān)鍵調(diào)控者,。他們認(rèn)為，如果以MCH為目標(biāo),，有望尋找到戒除可卡因癮性的新療法，甚至有可能找到戒除尼古丁上癮等針對(duì)其他物質(zhì)癮性的新療法,。（生物谷Bioon.com）
生物谷推薦原始出處：
PNAS April 2, 2009, doi: 10.1073/pnas.0811331106
The melanin-concentrating hormone system modulates cocaine reward
Shinjae Chunga,b, F. Woodward Hopfc, Hiroshi Nagasakid, Chun-Ying Lia, James D. Belluzzia, Antonello Boncic and Olivier Civellia,b,1
Drug addiction is mediated by complex neuronal processes that converge on the shell of the nucleus accumbens (NAcSh). The NAcSh receives inputs from the lateral hypothalamus (LH), where self-stimulation can be induced. Melanin-concentrating hormone (MCH) is produced mainly in the LH, and its receptor (MCH1R) is highly expressed in the NAcSh. We found that, in the NAcSh, MCH1R is coexpressed with dopamine receptors (D1R and D2R), and that MCH increases spike firing when both D1R and D2R are activated. Also, injecting MCH potentiates cocaine-induced hyperactivity in mice. Mice lacking MCH1R exhibit decreased cocaine-induced conditioned place preference, as well as cocaine sensitization. Using a specific MCH1R antagonist, we further show that acute blockade of the MCH system not only reduces cocaine self-administration, but also attenuates cue- and cocaine-induced reinstatement. Thus, the MCH system has an important modulatory role in cocaine reward and reinforcement by potentiating the dopaminergic system in the NAcSh, which may provide a new rationale for treating cocaine addiction.
