戒酒!! 用RASGRF-2當標靶 ?!!

Binge Drinking Gene: RASGRF-2 Helps Explain Teenage Alcohol Abuse, Scientists Say Reuters  Posted: 12/03/2012 5:25 pm EST Updated: 12/04/2012 8:49 am EST LONDON (Reuters) - Scientists have unpicked the brain processes involved in teenage alcohol abuse and say their findings help explain why some young people have more of a tendency to binge drink. A study published in the Proceedings of National Academy of Sciences (PNAS) journal found that a gene known as RASGRF-2 plays a crucial role in controlling how alcohol stimulates the brain to release dopamine, triggering feelings of reward. "If people have a genetic variation of the RASGRF-2 gene, alcohol gives them a stronger sense of reward, making them more likely to be heavy drinkers," said Gunter Schumann, who led the study at King's College London's Institute of Psychiatry. Alcohol and other addictive drugs activate the brain's dopamine systems, which induces feelings of pleasure and reward. Worldwide, some 2.5 million people die each year from the harmful use of alcohol, accounting for about 3.8 percent of all deaths, according to the World Health Organisation. Recent studies also carried out by scientists at the IoP have found that RASGRF-2 is a risk gene for alcohol abuse, but until now the mechanism involved in the process was not clear.  For this study, scientists initially looked at mice who had been modified to have the RASGRF2 gene removed, to see how they reacted to alcohol. They found the lack of RASGRF-2 was linked to a significant reduction in alcohol-seeking activity. They also discovered that when the mice did consume alcohol, the absence of RASGRF-2 reduced the activity of dopamine-releasing neurons in a region of the brain called the ventral tegmental area (VTA) - preventing the brain from releasing dopamine and limiting any sense of reward. The team then analyzed brain scans of 663 14-year old boys and found that when they were anticipating a reward in a mental test, those with genetic variations to the RASGRF2 gene had more activity in an area of the brain closely linked to the VTA and also involved in dopamine release. This suggests people with a genetic variation on the RASGRF-2 gene release more dopamine when anticipating a reward, and hence derive more pleasure from it, the scientists said. To confirm the findings, the team analyzed drinking behavior from the same group of boys two years later when many of them had already begun drinking frequently. They found that those with the RASGRF-2 gene variation drank more often at the age of 16 than those without it. "People seek out situations which fulfill their sense of reward and make them happy, so if your brain is wired to find alcohol rewarding, you will seek it out," Schumann said in a statement about the research. "We now understand the chain of action: how our genes shape this function in our brains and how that, in turn, leads to human behavior." Experts writing in The Lancet journal in February said up to 210,000 people in England and Wales will be killed prematurely by alcohol in the next 20 years, with a third of those preventable deaths due to liver disease alone.

英國研究發現"酗酒基因" 北京新浪網 (2012-12-05 07:42) 分享| 據新華社電 英國倫敦大學國王學院研究小組發現，一些人有一個"酗酒基因"，能在飲酒時刺激大腦分泌更多"快樂荷爾蒙"多巴胺，從而容易酗酒。研究小組在由美國《國家科學院學報》發表的論文中寫道，這一基因名為RASGRF－2，是多個可能與酗酒問題相關的基因之一。研究人員發現，與沒有這個基因的動物相比，有這一基因的動物更饞酒。研究小組征募663名14歲少年，讓他們執行一項有獎賞的任務，使得他們大腦的腹側紋狀體更活躍，這一部位關乎多巴胺釋放。掃描研究對象的大腦發現，RASGRF－2基因增強大腦的多巴胺反應。兩年後，研究人員詢問這些少年的飲酒習慣，發現攜帶RASGRF－2基因的研究對象飲酒頻率更高。按照英國國家醫療服務系統（NHS）的定義，酗酒是短時間內大量飲酒以致醉酒或感受到酒精影響。