亚麻醉剂量氯胺酮与人类意识改变状态。
Subanaesthetic ketamine and altered states of consciousness in humans.
机构信息
Department of Anesthesiology, Ann Arbor, MI, USA; Center for Consciousness Science, Ann Arbor, MI, USA.
Department of Anesthesiology, Ann Arbor, MI, USA; Center for Consciousness Science, Ann Arbor, MI, USA.
出版信息
Br J Anaesth. 2018 Jul;121(1):249-259. doi: 10.1016/j.bja.2018.03.011. Epub 2018 Apr 13.
BACKGROUND
Despite its designation as a 'dissociative anaesthetic,' the dissociative and psychoactive effects of ketamine remain incompletely understood. The goal of this study was to characterise the subjective experiences and accompanying EEG changes with subanaesthetic doses of ketamine.
METHODS
High-density EEG was recorded in 15 human volunteers before, during, and after subanaesthetic ketamine infusion (0.5 mg kg over 40 min), with self-reported measures of altered states of consciousness obtained after ketamine exposure. Sensor- and source-level EEG changes were analysed with a focus on spectral power and regional changes.
RESULTS
Ketamine-induced altered states were characterised predominantly by dissociative experiences such as disembodiment and ego transcendence; sensory disturbances were also common. Ketamine broadly decreased low-frequency power, with mean reductions largest at alpha (8-12 Hz) in parietal (-0.94 dB, P<0.001) and occipital (-1.8 dB, P<0.001) channel clusters. Significant decreases in alpha were identified in the precuneus and temporal-parietal junction.
CONCLUSIONS
Ketamine induces altered states of consciousness during periods of reduced alpha power in the precuneus and temporal-parietal junction. Modulation of these temporal-parietal loci are candidate mechanisms of the psychoactive effects of ketamine, given that this region is involved in multisensory integration, body representation, and consciousness.
背景
尽管氯胺酮被指定为“分离麻醉剂”，但其分离和致幻作用仍不完全清楚。本研究的目的是描述亚麻醉剂量氯胺酮的主观体验和伴随的 EEG 变化。
方法
在亚麻醉剂量氯胺酮输注（0.5mg/kg，持续 40 分钟）前后，15 名人类志愿者接受高密度 EEG 记录，并在氯胺酮暴露后获得改变的意识状态的自我报告测量。重点分析了传感器和源水平的 EEG 变化，包括频谱功率和区域变化。
结果
氯胺酮引起的改变状态主要表现为分离体验，如脱体和自我超越；感觉障碍也很常见。氯胺酮广泛降低低频功率，在顶叶（-0.94dB，P<0.001）和枕叶（-1.8dB，P<0.001）通道簇中，alpha（8-12Hz）的平均降低最大。在楔前叶和颞顶联合区发现 alpha 显著降低。
结论
氯胺酮在楔前叶和颞顶联合区的 alpha 功率降低期间诱导意识改变状态。鉴于该区域参与多感觉整合、身体表现和意识，对这些颞顶叶位置的调制是氯胺酮致幻作用的候选机制。
Zotero 插件