Ketamine effects on default mode network activity and vigilance: A randomized, placebo‐controlled crossover simultaneous fMRI/EEG study
Human Brain Mapping September 18, 2019 Norman Zacharias, Francesco Musso, Felix Müller et al. 70 citations
Resting-state brain activity is not steady but dynamic, with vigilance fluctuations playing a key role. In a randomized, double-blind, placebo-controlled crossover study of 24 healthy young adults, subanesthetic S-ketamine decreased functional connectivity in the medial prefrontal cortex and increased connectivity in intraparietal cortices, measured with simultaneous EEG-fMRI. Ketamine also shifted EEG power toward slow (delta, theta) and fast (gamma) frequencies. Frontal connectivity negatively related to EEG gamma and theta activity, while parietal connectivity positively related to delta power. These results indicate a direct link between ketamine-induced connectivity changes and reduced vigilance, offering potential surrogate endpoints for understanding ketamine's antidepressant effects.