State-Dependent and Bandwidth-Specific Effects of Ketamine and Propofol on Electroencephalographic Complexity in Rats
Frontiers in Systems Neuroscience August 11, 2020 Michael A. Brito, Duan Li, George A. Mashour et al. 15 citations
Ketamine and propofol anesthesia both reduce cortical complexity, but in different frequency bands. Using Lempel-Ziv complexity (LZc) to analyze electroencephalographic data from rats, the study found that ketamine anesthesia significantly reduced complexity in the high gamma range (65–175 Hz), while propofol anesthesia reduced complexity in lower frequencies (0.5–55 Hz). During emergence from ketamine anesthesia, complexity increased in broadband and low-frequency ranges. After normalizing for spectral influences, the reductions during anesthesia remained significant, indicating they are genuine neurophysiological features. The findings suggest that reduced high gamma complexity is a specific marker of ketamine anesthesia.