Topological analysis of differential effects of ketamine and propofol anaesthesia on brain dynamics.
Thomas F. Varley, Vanessa Denny, Olaf Sporns, Alice Patania
Royal Society Open Science June 23, 2021 DOI: 10.1098/rsos.201971 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational study Peer reviewed |
|---|---|
| Sample size | 2 |
| Population | Macaques |
| Interventions | Propofol Ketamine |
| Topics | Ketamine Esketamine |
| Keywords | Dynamics Propofol Attractor Anaesthesia Consciousness |
| Key findings | Awake cortical dynamics showed the richest structure, visiting the most states with pronounced higher-order structures and the least deterministic dynamics. Propofol shifted dynamics toward an impoverished, constrained, low-structure regime, while ketamine was less complex than awake but remained well above propofol on almost all measures. |
Abstract
Research has found that the vividness of conscious experience is related to brain dynamics. Despite both being anaesthetics, propofol and ketamine produce different subjective states: we explore the different effects of these two anaesthetics on the structure of dynamic attractors reconstructed from electrophysiological activity recorded from cerebral cortex of two macaques. We used two methods: the first embeds the recordings in a continuous high-dimensional manifold on which we use topological data analysis to infer the presence of higher-order dynamics. The second reconstruction, an ordinal partition network embedding, allows us to create a discrete state-transition network, which is amenable to information-theoretic analysis and contains rich information about state-transition dynamics. We find that the awake condition generally had the 'richest' structure, visiting the most states, the presence of pronounced higher-order structures, and the least deterministic dynamics. By contrast, the propofol condition had the most dissimilar dynamics, transitioning to a more impoverished, constrained, low-structure regime. The ketamine condition, interestingly, seemed to combine aspects of both: while it was generally less complex than the awake condition, it remained well above propofol in almost all measures. These results provide deeper and more comprehensive insights than what is typically gained by using point-measures of complexity.
Comparable studies
Other preclinical and animal studies on ketamine, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| mTOR-Dependent Synapse Formation Underlies the Rapid Antidepressant Effects of NMDA Antagonists Rats | 2010 | Observational study | |
| Activation of Glutamatergic Neurotransmission by Ketamine: A Novel Step in the Pathway from NMDA Receptor Blockade to Dopaminergic and Cognitive Disruptions Associated with the Prefrontal Cortex Conscious rats | 1997 | Dose-response study with microdialysis and behavioral testing | |
| NMDAR inhibition-independent antidepressant actions of ketamine metabolites Mice | 2016 | Preclinical study | |
| The dissociative anaesthetics, ketamine and phencyclidine, selectively reduce excitation of central mammalian neurones by N‐methyl‐aspartate Spinal neurons in decerebrate or pentobarbitone-anaesthetized cats and rats | 1983 | Experimental study | |
| R-ketamine: a rapid-onset and sustained antidepressant without psychotomimetic side effects Mice | 2015 | Experimental study |
Citations in the library
Cited by 11
- Brain network integration dynamics are associated with loss and recovery of consciousness induced by sevoflurane Human Brain Mapping March 19, 2021
- What it is like to be a bit: an integrated information decomposition account of emergent mental phenomena Neuroscience of Consciousness November 1, 2021
- The lack of temporal brain dynamics asymmetry as a signature of impaired consciousness states Interface Focus April 14, 2023
- Dynamic reconfiguration of frequency-specific cortical coactivation patterns during psychedelic and anesthetized states induced by ketamine Neuroimage January 7, 2022
- Psilocybin enhances insightfulness in meditation: a perspective on the global topology of brain imaging during meditation. Scientific Reports March 26, 2024
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Cites 18
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- Neural correlates of consciousness: progress and problems Nature Reviews Neuroscience April 20, 2016
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- The entropic brain: a theory of conscious states informed by neuroimaging research with psychedelic drugs Frontiers in Human Neuroscience 2014
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and 13 more in the library