Resting-State Functional EEG Connectivity in Salience and Default Mode Networks and their Relationship to Dissociative Symptoms During NMDA Receptor Antagonism.
S. de la Salle, J. Choueiry, D. Shah, H. Bowers, J. McIntosh, V. Ilivitsky, Brooke Carroll, V. Knott
Pharmacology, Biochemistry and Behavior December 29, 2020 DOI: 10.1016/j.pbb.2020.173092 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Experimental study Peer reviewed |
|---|---|
| Sample size | 21 |
| Population | Healthy volunteers |
| Intervention | Ketamine |
| Dose | subanesthetic dose |
| Topics | Default mode network |
| Key findings | Ketamine produced dissociation symptoms and frequency-dependent increases and decreases in EEG connectivity within and between the default mode and salience networks. The authors argue these altered network couplings and emergent dissociative symptoms tentatively support an NMDAR-hypofunction hypothesis of disturbed electrophysiologic connectivity in schizophrenia. |
Abstract
N-methyl-D-aspartate receptor (NMDAR) antagonists administered to healthy humans results in schizophrenia-like symptoms, which are thought in part to be related to glutamatergically altered electrophysiological connectivity in large-scale intrinsic functional brain networks. Here, we examine resting-state source electroencephalographic (EEG) connectivity within and between the default mode (DMN: for self-related cognitive activity) and salience networks (SN: for detection of salient stimuli in internal and external environments) in 21 healthy volunteers administered a subanesthetic dose of the dissociative anesthetic and NMDAR antagonist, ketamine. In addition to provoking symptoms of dissociation, which are thought to originate from an altered sense of self that is common to schizophrenia, ketamine induces frequency-dependent increases and decreases in connectivity within and between DMN and SN. These altered interactive network couplings together with emergent dissociative symptoms tentatively support an NMDAR-hypofunction hypothesis of disturbed electrophysiologic connectivity in schizophrenia.