Carhart-Harris Robin L, Muthukumaraswamy Suresh, Roseman Leor, Kaelen Mendel, Droog Wouter, Murphy Kevin, Tagliazucchi Enzo, Schenberg Eduardo E, Nest Timothy, Orban Csaba, Leech Robert, Williams Luke T, Williams Tim M, Bolstridge Mark, Sessa Ben, McGonigle John, Sereno Martin I, Nichols David, Hellyer Peter J, Hobden Peter, Evans John, Singh Krish D, Wise Richard G, Curran H Valerie, Feilding Amanda, Nutt David J
Centre for Neuropsychopharmacology, Department of Medicine, Imperial College London, W12 0NN, London, United Kingdom;
Department of Psychology, Cardiff University Brain Research Imaging Centre, CF10 3AT, Cardiff, United Kingdom; School of Pharmacy, University of Auckland, 1142 Auckland, New Zealand; School of Psychology, University of Auckland, 1142 Auckland, New Zealand;
Proc Natl Acad Sci U S A. 2016 Apr 26;113(17):4853-8. doi: 10.1073/pnas.1518377113. Epub 2016 Apr 11.
Lysergic acid diethylamide (LSD) is the prototypical psychedelic drug, but its effects on the human brain have never been studied before with modern neuroimaging. Here, three complementary neuroimaging techniques: arterial spin labeling (ASL), blood oxygen level-dependent (BOLD) measures, and magnetoencephalography (MEG), implemented during resting state conditions, revealed marked changes in brain activity after LSD that correlated strongly with its characteristic psychological effects. Increased visual cortex cerebral blood flow (CBF), decreased visual cortex alpha power, and a greatly expanded primary visual cortex (V1) functional connectivity profile correlated strongly with ratings of visual hallucinations, implying that intrinsic brain activity exerts greater influence on visual processing in the psychedelic state, thereby defining its hallucinatory quality. LSD's marked effects on the visual cortex did not significantly correlate with the drug's other characteristic effects on consciousness, however. Rather, decreased connectivity between the parahippocampus and retrosplenial cortex (RSC) correlated strongly with ratings of "ego-dissolution" and "altered meaning," implying the importance of this particular circuit for the maintenance of "self" or "ego" and its processing of "meaning." Strong relationships were also found between the different imaging metrics, enabling firmer inferences to be made about their functional significance. This uniquely comprehensive examination of the LSD state represents an important advance in scientific research with psychedelic drugs at a time of growing interest in their scientific and therapeutic value. The present results contribute important new insights into the characteristic hallucinatory and consciousness-altering properties of psychedelics that inform on how they can model certain pathological states and potentially treat others.
麦角酸二乙酰胺（LSD）是典型的致幻药物，但此前从未使用现代神经影像学对其对人脑的影响进行过研究。在此，在静息状态下实施了三种互补的神经影像学技术：动脉自旋标记（ASL）、血氧水平依赖（BOLD）测量和脑磁图（MEG），结果显示服用LSD后脑活动发生了显著变化，且这些变化与其特征性心理效应密切相关。视觉皮层脑血流量（CBF）增加、视觉皮层α波功率降低以及初级视觉皮层（V1）功能连接图谱大幅扩展，这些都与视幻觉评分密切相关，这意味着在致幻状态下，大脑内在活动对视知觉加工产生了更大影响，从而决定了其幻觉特质。然而，LSD对视觉皮层的显著影响与该药物对意识的其他特征性影响并无显著关联。相反，海马旁回与压后皮质（RSC）之间的连接减少与“自我消融”和“意义改变”评分密切相关，这意味着这一特定神经回路对于维持“自我”及其对“意义”的加工具有重要意义。在不同成像指标之间也发现了密切关系，从而能够更有力地推断它们的功能意义。在人们对致幻药物的科学和治疗价值兴趣日益浓厚之际，对LSD状态进行的这种独特而全面的研究代表了致幻药物科学研究的一项重要进展。目前的研究结果为致幻剂的特征性幻觉和意识改变特性提供了重要的新见解，有助于了解它们如何模拟某些病理状态以及潜在地治疗其他病理状态。
