美国科学家研究发现，大脑中一个名为岛叶的区域受损后，烟民的烟瘾就会消失。但科学家同时提醒人们，千万不要因此将损伤大脑作为戒烟的方法。
美国南加州大学的安托万·贝沙拉等人２５日在《科学》杂志上介绍说，岛叶又称脑岛，位于大脑外侧裂深处，约一个硬币大。他们最初注意到这一特殊区域是因为一位患者中风前后的迥异表现。这位烟民中风前每天要抽两包烟，但在中风导致岛叶受损后却一支烟也不抽，说是“身体忘记了抽烟的欲望”。
科学家因此推测，对岛叶的损害有可能帮助戒烟。他们于是选取了１９名岛叶受损和５０名大脑其他部位受损的吸烟者进行进一步研究。这些人在脑部受损前都有两年以上的吸烟史，每天吸烟都超过５支。研究结果发现，岛叶受损的１９人中有１３人成功戒烟，至今没有反复；其他５０人中有个别人成功戒烟。总体来看，岛叶受损者戒烟最容易。
贝沙拉认为，新发现具有巨大的药理学潜力。但他同时强调，由于人体许多日常功能都与岛叶有关，在根据这一发现研究戒烟新方法时应避免殃及人的食欲等正常机能。
此前已有研究发现，岛叶会被某些与致瘾物质有关的信号激活，比如看到有人吸毒时，岛叶就会有所反应。但与大脑其他部位相比，科学家以前在研究致瘾物质时很少关注岛叶。
英文原文：
Area in Brain Key to Quit Smoking?
Damage to Specific Brain Area Banishes Smoking Addiction Urge, Study Shows
Jan. 16, 2007 -- A strokestroke patient who quit smokingquit smoking because his "body forgot the urge to smoke" may hold the key that unlocks the chains of addiction.
That key appears to be a region on the right and left sides of the brain called the insula.
The insula is thought to control conscious urges. One study showed that drug addicts who relapse have high-level insula activity during decision-making tasks.
"What happens to addictions when there's damage to the insula?" wondered Antoine Bechara, PhD, of the universities of Southern California and Iowa.
To find out, Bechara, along with Hanna Damasio of USC and other colleagues, compared people who quit smoking after injury to the insula with those who quit after suffering brain damage that did not include the insula. Not all of the patients had strokes.
Twelve of 13 patients with damage to the insula quit smoking soon after their brain damage, never started smoking again, found it easy to quit, and, after quitting, never again felt the urge to smoke. In other words, they lost their smoking addiction.
Loss of smoking addiction occurred in only four of 19 patients without insula damage.
The experience of the patient who said his body forgot the urge to smoke "suggests that the insula plays a role in the feeling that smoking is a bodily need," Bechara and colleagues conclude.
None of the insula-damaged patients who lost their smoking addiction lost their desire for food or ate less.
This suggests that insula damage does not make a person lose fundamental urges. Instead, the researchers suggest, insula damage affects only "learned pleasures."
This means the insula may also control other kinds of addiction.
Brain surgery isn't a solution to cigarette smoking or other addictions. But, Bechara says, the insula could be a target for new drug treatments.
"There is a lot of potential for pharmacological developments," he says in a news release.
Bechara and colleagues report their findings in the Jan. 26 issue of Science.
