有沖動(dòng)的感覺(jué)嗎？據(jù)在健康志愿者身上所做的一項(xiàng)新的研究,，做輕率魯莽決定的傾向源自于多巴胺受體活性的降低以及隨之而來(lái)的多巴胺在腦中釋放的增加,。 Joshua Buckholtz及其同事知道,，這種特別的神經(jīng)遞質(zhì)與人類(lèi)的沖動(dòng)行為有關(guān)，因此他們對(duì)32名實(shí)驗(yàn)參與者的腦子進(jìn)行了掃描,，在掃描的時(shí)候,，這些受試者攝取了一劑安非他命以觀察在多巴胺濃度與人類(lèi)沖動(dòng)行為之間的實(shí)際相關(guān)性。 研究人員用他們的數(shù)據(jù)創(chuàng)制了一個(gè)模型,。在一篇Brevium的文章中,，他們用該模型顯示，那些有著很強(qiáng)沖動(dòng)行為的人顯示出多巴胺受體D2的結(jié)合活性較低,，但他們對(duì)刺激（如安非他命）反應(yīng)所釋放出的多巴胺卻有所增加,。
這意味著，一個(gè)人的D2自體受體的可獲得性差異可幫助預(yù)測(cè)這個(gè)人所展現(xiàn)的沖動(dòng)行為的表達(dá),。 由于沖動(dòng)還與藥物濫用及以往的成癮性有關(guān),，研究人員提示，這種D2活性的降低（以及接著發(fā)生的在其它部位多巴胺釋放的增加）可能同樣也與藥物的成癮性有關(guān),。（生物谷Bioon.com）
生物谷推薦原文出處：
Science DOI: 10.1126/science.1185778
Dopaminergic Network Differences in Human Impulsivity
Joshua W. Buckholtz,1,2,*, Michael T. Treadway,1, Ronald L. Cowan,3,4 Neil D. Woodward,3,4 Rui Li,5 M. Sib Ansari,5 Ronald M. Baldwin,5 Ashley N. Schwartzman,1 Evan S. Shelby,1 Clarence E. Smith,3 Robert M. Kessler,5 David H. Zald1,3
Dopamine (DA) has long been implicated in impulsivity, but the precise mechanisms linking human variability in DA signaling to differences in impulsive traits remain largely unknown. By using a dual-scan positron emission tomography approach in healthy human volunteers with amphetamine and the D2/D3 ligand [18F]fallypride, we found that higher levels of trait impulsivity were predicted by diminished midbrain D2/D3 autoreceptor binding and greater amphetamine-induced DA release in the striatum, which was in turn associated with stimulant craving. Path analysis confirmed that the impact of decreased midbrain D2/D3 autoreceptor availability on trait impulsivity is mediated in part through its effect on stimulated striatal DA release.
1 Department of Psychology, Vanderbilt University, Nashville, TN 37240, USA.
2 Neuroscience Graduate Program, Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240, USA.
3 Department of Psychiatry, Vanderbilt University, Nashville, TN 37240, USA.
4 Psychiatric Neuroimaging Program, Vanderbilt University, Nashville, TN 37240, USA.
5 Department of Radiology, Vanderbilt University, Nashville, TN 37240, USA.
These authors contributed equally to this work.
