Proceedings of the National Academy of Sciences
September 25, 2012
Alan Anticevic, Mark G. Gancsos, John D. Murray et al.
260 citations
Glutamate signaling through NMDA receptors is essential for brain computations that support cognition, and its disruption may contribute to schizophrenia. Using ketamine, an NMDA receptor antagonist, the study found that the normal anticorrelation between the default-mode and task-positive brain systems was disrupted during a working memory task. The degree of this disruption predicted task performance and produced schizophrenia-like symptoms. A computational model suggests that cortical disinhibition underlies this effect, linking glutamate's role in large-scale brain organization to cognition and psychiatric symptoms.
Elife
April 17, 2024
Flora Moujaes, Jie Lisa Ji, Masih Rahmati et al.
23 citations
Ketamine is a promising treatment for treatment-resistant depression, but why people respond differently is poorly understood. In a single-blind placebo-controlled study, 40 healthy participants received acute ketamine. Using data-driven global brain connectivity, the neural and behavioral effects of ketamine were found to be multi-dimensional, reflecting robust inter-individual variability. Ketamine's principal neural gradient matched somatostatin and parvalbumin cortical gene expression patterns, while the mean effect did not. Behavioral symptom variation mapped onto distinct neural gradients resolvable at the single-subject level. These results highlight the importance of individual variation for developing precise pharmacological biomarkers in psychiatry.
EClinicalMedicine
January 1, 2026
Henrique Nunes Pereira Oliva, Tiago Paiva Prudente, Alisson M Paredes Naveda et al.
5 citations
Sleep disturbances are common in people with substance use disorders and often persist after stopping use. This systematic review and meta-analysis of 43 studies with about 7500 participants examined sleep abnormalities linked to alcohol, benzodiazepine, cannabis, cocaine, methamphetamine, nicotine, and opioid use disorders. Total sleep time was reduced in alcohol, nicotine, and opioid use disorders. Slow-wave sleep was reduced in alcohol and cocaine use disorders. Sleep quality, measured by the Pittsburgh Sleep Quality Index, was poorer in alcohol, cocaine, and nicotine use disorders. No studies met criteria for benzodiazepine or methamphetamine use disorders. Results suggest specific substances relate to distinct sleep problems, highlighting areas for further research.
bioRxiv Preprint Server
November 1, 2022
Flora Moujaes, Jie Lisa Ji, Masih Rahmati et al.
4 citations
preprint
Ketamine is a promising therapy for treatment-resistant depression, but why some people respond better than others remains unclear. The molecular mechanisms of ketamine are not yet connected to its effects on brain activity and behavior.
bioRxiv Preprint Server
February 10, 2025
Masih Rahmati, Flora Moujaes, Nina Purg Suljič et al.
1 citation
preprint
Working memory deficits in disorders like schizophrenia may stem from disrupted brain cell tuning. Using fMRI, researchers found that ketamine, which blocks NMDA receptors, broadens neural spatial tuning in healthy people, reducing the precision of brain responses across visual, parietal, and frontal areas and worsening spatial working memory accuracy. These tuning changes were more consistent across individuals and brain regions than overall activation changes and correlated with memory performance. The results link NMDA receptor disruption to altered brain circuit dynamics and memory impairment, offering a target for developing treatments.
medRxiv Preprint Server
April 10, 2020
Chadi G. Abdallah, Kyung-Heup Ahn, Lynnette A. Averill et al.
1 citation
preprint
A robust and reproducible brain connectivity fingerprint (CFP) was identified during ketamine infusion in healthy participants, characterized by reduced connectivity within primary cortices and the executive network, but increased connectivity between the executive network and the rest of the brain. This same CFP measured one week after treatment in major depressive disorder patients predicted response to eight weeks of sertraline, but not placebo. The findings suggest a brain network biomarker that links ketamine's acute effects to the mechanisms of conventional antidepressants.
Consciousness and Cognition
June 1, 2011
Michelle Neider, Edward F Pace-Schott, Erica Forselius et al.
Greater lucidity in dreams is linked to better performance on a task that engages the ventromedial prefrontal cortex (the Iowa Gambling Task), but not on a task engaging the dorsolateral prefrontal cortex (the Wisconsin Card Sort Task). In a prospective study of 28 high school students, those with higher lucidity scored significantly higher on the Iowa Gambling Task. No differences were found in sleep quality or baseline characteristics. The findings suggest a connection between lucid dreaming and ventromedial prefrontal function.