一個(gè)設(shè)計(jì)用于更好地理解為什么吸煙者對于香煙如此上癮的研究發(fā)現(xiàn),，尼古丁依賴無法僅僅通過成癮的吸煙者的大腦和肺的尼古丁更快速積累加以解釋,。Jed Rose及其同事利用正電子發(fā)射斷層成像技術(shù)（PET）比較了13位成癮吸煙者和10位沒有成癮的吸煙者的肺和大腦的尼古丁積累。
此前一個(gè)被稱為Russell的“high nicotine boli”的假說提出,，大腦的尼古丁濃度在每吸一口香煙后都會達(dá)到峰值，而這些峰值可能與成癮有關(guān),。這次的研究沒有發(fā)現(xiàn)這種峰值,。相反，這組科學(xué)家證明了尼古丁在大腦中穩(wěn)步積累,，而且在這兩組吸煙者吸完一整根煙之后在大腦達(dá)到了峰值,。這組作者報(bào)告說，成癮吸煙者比非成癮吸煙者的大腦中的積累更加緩慢,，這部分是由于尼古丁從成癮吸煙者的肺沖刷出去并進(jìn)入血液的效率更低,。 這組科學(xué)家提出，成癮吸煙者通過吸入更大體積的煙從而補(bǔ)償更緩慢的尼古丁積累,。
這項(xiàng)研究可能有助于為試圖戒煙的吸煙者提供一種治療計(jì)劃,。（生物谷Bioon.com）
相關(guān)研究：
Nature：尼古丁受體研究取得新進(jìn)展
Neuron：尼古丁哄騙大腦產(chǎn)生積極記憶
Nature：查明尼古丁上癮原因
生物谷推薦原始出處：
PNAS March 8, 2010, doi: 10.1073/pnas.0909184107
Kinetics of brain nicotine accumulation in dependent and nondependent smokers assessed with PET and cigarettes containing 11C-nicotine
Jed E. Rosea,1, Alexey G. Mukhina, Stephen J. Lokitza,b, Timothy G. Turkingtonb, Joseph Herskovica, Frederique M. Behmb, Sudha Gargc, and Pradeep K. Gargc
aCenter for Nicotine and Smoking Cessation Research and
bDepartment of Radiology, Duke University Medical Center, Durham, NC 27705; and
cDepartment of Radiologic Sciences, Wake Forest University Baptist Medical Center, Winston-Salem, NC 27157
Tobacco smoking is a chronic, relapsing disorder that constitutes one of the primary preventable causes of death in developed countries. Two of the popular hypotheses to explain the development and maintenance of strong nicotine dependence in cigarette smokers posit (i) a rapid brain nicotine accumulation during cigarette smoking and/or (ii) puff-associated spikes in brain nicotine concentration. To address these hypotheses, we investigated the dynamics of nicotine accumulation in the smoker's brain during actual cigarette smoking using PET with 3-s temporal resolution and 11C-nicotine loaded into cigarettes. The results of the study, performed in 13 dependent smokers (DS) and 10 nondependent smokers (NDS), suggest that puff-associated spikes in the brain nicotine concentration do not occur during habitual cigarette smoking. Despite the presence of a puff-associated oscillation in the rate of nicotine accumulation, brain nicotine concentration gradually increases during cigarette smoking. The results further suggest that DS have a slower process of brain nicotine accumulation than NDS because they have slower nicotine washout from the lungs and that DS have a tendency to compensate for their slower rate of brain nicotine accumulation compared with NDS by inhaling a larger volume of smoke. For these reasons, smokers’ dependence on cigarette smoking, or the resistance of NDS to becoming dependent, cannot be explained solely by a faster brain nicotine accumulation.
