Convergent effects of different anesthetics on changes in phase alignment of cortical oscillations.
Cell reports – May 27, 2025
Source: PubMed
Summary
Different anesthetics disrupt consciousness in surprisingly similar ways, despite their varied chemical properties. Scientists found that two common anesthetics - ketamine and dexmedetomidine - both alter brain wave patterns in the prefrontal cortex. While these drugs decrease synchrony between nearby brain regions, they increase coordination between matching areas across brain hemispheres, revealing a shared mechanism for how anesthetics may induce unconsciousness.
Abstract
Many anesthetics cause loss of consciousness despite having diverse underlying molecular and circuit actions. To explore the convergent effects of these drugs, we examine how anesthetic doses of ketamine and dexmedetomidine affect bilateral oscillations in the prefrontal cortex of nonhuman primates. Both anesthetics increase phase locking in the ventrolateral and dorsolateral prefrontal cortex, within and across hemispheres. However, the nature of the phase locking varies. Neighboring prefrontal subregions within a hemisphere show decreased phase alignment with both drugs. Local analyses within a region suggest that this finding could be explained by broad cortical distance-based effects, such as large traveling waves. In contrast, homologous areas across hemispheres become more aligned in phase. Our results suggest that both anesthetics induce strong patterns of cortical phase alignment that are markedly different from those during waking and that these patterns may be a common feature driving loss of responsiveness from different anesthetic drugs.