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Oluwaseun Akeju

9 papers in the library · 358 citations · publishing 2019-2024

Papers

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Ketamine can produce oscillatory dynamics by engaging mechanisms dependent on the kinetics of NMDA receptors.

Proceedings of the National Academy of Sciences of the United States of America May 28, 2024 Elie Adam, Marek Kowalski, Oluwaseun Akeju et al. 30 citations

Ketamine is an N-methyl-D-aspartate (NMDA)-receptor antagonist that produces sedation, analgesia, and dissociation at low doses and profound unconsciousness with antinociception at high doses. At high and low doses, ketamine can generate gamma oscillations (>25 Hz) in the electroencephalogram (EEG). The gamma oscillations are interrupted by slow-delta oscillations (0.1 to 4 Hz) at high doses....

Characterizing brain dynamics during ketamine-induced dissociation and subsequent interactions with propofol using human intracranial neurophysiology

Nature Communications March 29, 2023 Fangyun Tian, Laura D. Lewis, David W. Zhou et al. 63 citations

The neural mechanisms underpinning ketamine’s dissociative and antidepressant effects remain poorly understood. Here, the authors analyzed ketamine-induced brain dynamics with intracranial recordings in humans and found that ketamine engages different brain areas in distinct frequency-dependent patterns that may relate to its dissociative and antidepressant effects. Ketamine produces...

Characterizing ketamine-induced dissociation using human intracranial neurophysiology: brain dynamics, network activity, and interactions with propofol

bioRxiv Preprint Server May 2, 2022 Fangyun Tian, Laura D. Lewis, David W. Zhou et al. preprint

Subanesthetic doses of ketamine produce rapid and sustained anti-depressant effects in patients with treatment-resistant depression. Unfortunately, the usefulness of ketamine as a treatment is limited by its potential for abuse because of psychotropic side effects such as dissociation. Understanding the brain dynamics and the neural circuits involved in ketamine’s effects could lend insight...

Ketamine induces EEG oscillations that may aid anesthetic state but not dissociation monitoring

Clinical Neurophysiology October 1, 2021 Shubham Chamadia, Jacob Gitlin, Jennifer Mekonnen et al.

Objective: Ketamine is an anesthetic drug associated with dissociation. Decreased electroencephalogram alpha (8 to 13 Hz) and low-beta (13 to 20 Hz) oscillation power have been associated with ketamine-induced dissociation. We aimed to characterize surface electroencephalogram signatures that may serve as biomarkers for dissociation. Methods: We analyzed data from a single-site, open-label,...

A hidden Markov model reliably characterizes ketamine-induced spectral dynamics in macaque local field potentials and human electroencephalograms

PLoS Computational Biology August 18, 2021 Sourish Chakravarty, Indie C. Garwood, S. Chakravarty et al. 32 citations

Ketamine is an NMDA receptor antagonist commonly used to maintain general anesthesia. At anesthetic doses, ketamine causes high power gamma (25-50 Hz) oscillations alternating with slow-delta (0.1-4 Hz) oscillations. These dynamics are readily observed in local field potentials (LFPs) of non-human primates (NHPs) and electroencephalogram (EEG) recordings from human subjects. However, a detailed...

Dissociative and analgesic properties of ketamine are independent and unaltered by sevoflurane general anesthesia

PAIN Reports June 3, 2021 Eunice Y. Hahm, Shubham Chamadia, J. Locascio et al. 6 citations

Ketamine-induced dissociation and analgesia are independent and robust to general anesthesia neural circuit alterations, suggesting that ketamine can be refined into a targeted pain therapeutic. Abstract Introduction: Ketamine, an anesthetic adjunct, is routinely administered as part of a balanced general anesthetic technique. We recently showed that the acute analgesic and dissociation...

A hidden Markov model reliably characterizes ketamine-induced spectral dynamics in macaque LFP and human EEG

medRxiv November 16, 2020 Indie C. Garwood, S. Chakravarty, Jacob Donoghue et al. preprint

Abstract Ketamine is an NMDA receptor antagonist commonly used to maintain general anesthesia. At anesthetic doses, ketamine causes bursts of 30-50 Hz oscillations alternating with 0.1 to 10 Hz oscillations. These dynamics are readily observed in local field potentials (LFPs) of non-human primates (NHPs) and electroencephalogram (EEG) recordings from human subjects. However, a detailed...

The dissociative and analgesic properties of ketamine are independent

Anesthesiology September 4, 2020 Jacob Gitlin, Shubham Chamadia, J. Locascio et al. 48 citations

Background: Ketamine is a dissociative anesthetic with analgesic properties. Ketamine’s analgesic properties have been suggested to result from its dissociative properties. To the authors’ knowledge, this postulate is unsubstantiated. The authors hypothesize that the dissociative and analgesic properties of ketamine are independent. Methods: The authors conducted a single-site, open-label study...

Repeat-dose ketamine augmentation for treatment-resistant depression with chronic suicidal ideation: A randomized, double blind, placebo controlled trial.

Journal of Affective Disorders 2019 Dawn F. Ionescu, Kate H Bentley, M. Eikermann et al. 179 citations

BACKGROUND Several studies indicate that ketamine has rapid antidepressant effects in patients with treatment-resistant depression (TRD). The extent to which repeated doses of ketamine (versus placebo) reduce depression in the short and long term among outpatients with TRD and chronic, current suicidal ideation remains unknown. METHODS Twenty-six medicated outpatients with severe major...