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Bharmauria V, Ramezanpour H, Ouelhazi A, Yahia Belkacemi Y, Flouty O, Molotchnikoff S. KETAMINE: Neural- and network-level changes. Neuroscience 2024; 559:188-198. [PMID: 39245312 DOI: 10.1016/j.neuroscience.2024.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2024] [Revised: 08/30/2024] [Accepted: 09/03/2024] [Indexed: 09/10/2024]
Abstract
Ketamine is a widely used clinical drug that has several functional and clinical applications, including its use as an anaesthetic, analgesic, anti-depressive, anti-suicidal agent, among others. Among its diverse behavioral effects, it influences short-term memory and induces psychedelic effects. At the neural level across different brain areas, it modulates neural firing rates, neural tuning, brain oscillations, and modularity, while promoting hypersynchrony and random connectivity between neurons. In our recent studies we demonstrated that topical application of ketamine on the visual cortex alters neural tuning and promotes vigorous connectivity between neurons by decreasing their firing variability. Here, we begin with a brief review of the literature, followed by results from our lab, where we synthesize a dendritic model of neural tuning and network changes following ketamine application. This model has potential implications for focused modulation of cortical networks in clinical settings. Finally, we identify current gaps in research and suggest directions for future studies, particularly emphasizing the need for more animal experiments to establish a platform for effective translation and synergistic therapies combining ketamine with other protocols such as training and adaptation. In summary, investigating ketamine's broader systemic effects, not only provides deeper insight into cognitive functions and consciousness but also paves the way to advance therapies for neuropsychiatric disorders.
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Affiliation(s)
- Vishal Bharmauria
- The Tampa Human Neurophysiology Lab & Department of Neurosurgery and Brain Repair, Morsani College of Medicine, 2 Tampa General Circle, University of South Florida, Tampa, FL 33606, USA; Centre for Vision Research and Centre for Integrative and Applied Neuroscience, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada.
| | - Hamidreza Ramezanpour
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada
| | - Afef Ouelhazi
- Neurophysiology of the Visual system, Département de Sciences Biologiques, 1375 Av. Thérèse-Lavoie-Roux, Université de Montréal, Montréal, Québec H2V 0B3, Canada
| | - Yassine Yahia Belkacemi
- Neurophysiology of the Visual system, Département de Sciences Biologiques, 1375 Av. Thérèse-Lavoie-Roux, Université de Montréal, Montréal, Québec H2V 0B3, Canada
| | - Oliver Flouty
- The Tampa Human Neurophysiology Lab & Department of Neurosurgery and Brain Repair, Morsani College of Medicine, 2 Tampa General Circle, University of South Florida, Tampa, FL 33606, USA
| | - Stéphane Molotchnikoff
- Neurophysiology of the Visual system, Département de Sciences Biologiques, 1375 Av. Thérèse-Lavoie-Roux, Université de Montréal, Montréal, Québec H2V 0B3, Canada
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Jiang Y, Sleigh J. Consciousness and General Anesthesia: Challenges for Measuring the Depth of Anesthesia. Anesthesiology 2024; 140:313-328. [PMID: 38193734 DOI: 10.1097/aln.0000000000004830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
The optimal consciousness level required for general anesthesia with surgery is unclear, but in existing practice, anesthetic oblivion, may be incomplete. This article discusses the concept of consciousness, how it is altered by anesthetics, the challenges for assessing consciousness, currently used technologies for assessing anesthesia levels, and future research directions. Wakefulness is marked by a subjective experience of existence (consciousness), perception of input from the body or the environment (connectedness), the ability for volitional responsiveness, and a sense of continuity in time. Anesthetic drugs may selectively impair some of these components without complete extinction of the subjective experience of existence. In agreement with Sanders et al. (2012), the authors propose that a state of disconnected consciousness is the optimal level of anesthesia, as it likely avoids both awareness and the possible dangers of oversedation. However, at present, there are no reliably tested indices that can discriminate between connected consciousness, disconnected consciousness, and complete unconsciousness.
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Affiliation(s)
- Yandong Jiang
- Department of Anesthesiology, Critical Care and Pain Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas
| | - Jamie Sleigh
- Department of Anesthesiology, University of Auckland, Hamilton, New Zealand
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Zhang L, Vogt K. Psychometric and next day electrodermal activity data from an experiment involving midazolam, ketamine, and painful stimulation. Data Brief 2023; 51:109634. [PMID: 37840992 PMCID: PMC10568555 DOI: 10.1016/j.dib.2023.109634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 09/15/2023] [Accepted: 09/25/2023] [Indexed: 10/17/2023] Open
Abstract
This is a report of unpublished data obtained from a randomized, single-blind, within-subject crossover design, neuroimaging trial comparing the effects of midazolam and ketamine on memory and pain. An experimental auditory paradigm paired with the periodic pain was used to examine auditory encoding and subsequent recognition. Psychometric surveys assessed stress, anxiety, depression, and pain behaviors. These data were collected to potentially characterize inter-subject variation during analysis. Electrodermal activity was measured to examine the association between previous pain-pairing of experimental items and autonomic responses during next day recognition memory testing, with exposure to the same auditory word items. Electrodermal responses were determined using an event-related analysis approach. These data may help shape future experiments using psychometric data to characterize individual responses or using next day electrodermal activity to determine conditioned responses to previously-experienced aversive stimuli.
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Affiliation(s)
- Lindsay Zhang
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh School of Medicine, A-1305 Scaife Hall, 3550 Terrace Street, Pittsburgh, PA 15261, USA
| | - Keith Vogt
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh School of Medicine, A-1305 Scaife Hall, 3550 Terrace Street, Pittsburgh, PA 15261, USA
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Vogt KM, Ibinson JW, Burlew AC, Smith CT, Aizenstein HJ, Fiez JA. Brain connectivity under light sedation with midazolam and ketamine during task performance and the periodic experience of pain: Examining concordance between different approaches for seed-based connectivity analysis. Brain Imaging Behav 2023; 17:519-529. [PMID: 37166623 PMCID: PMC10543548 DOI: 10.1007/s11682-023-00782-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2023] [Indexed: 05/12/2023]
Abstract
This work focused on functional connectivity changes under midazolam and ketamine sedation during performance of a memory task, with the periodic experience of pain. To maximize ability to compare to previous and future work, we performed secondary region of interest (ROI)-to-ROI functional connectivity analyses on these data, using two granularities of scale for ROIs. These findings are compared to the results of a previous seed-to-voxel analysis methodology, employed in the primary analysis. Healthy adult volunteers participated in this randomized crossover 3 T functional MRI study under no drug, followed by subanesthetic doses of midazolam or ketamine achieving minimal sedation. Periodic painful stimulation was delivered while subjects repeatedly performed a memory-encoding task. Atlas-based and network-level ROIs were used from within Conn Toolbox (ver 18). Timing of experimental task events was regressed from the data to assess drug-induced changes in background connectivity, using ROI-to-ROI methodology. Compared to saline, ROI-to-ROI connectivity changes under ketamine did not survive correction for multiple comparisons, thus data presented is from 16 subjects in a paired analysis between saline and midazolam. In both ROI-to-ROI analyses, the predominant direction of change was towards increased connectivity under midazolam, compared to saline. These connectivity increases occurred between functionally-distinct brain areas, with a posterior-predominant spatial distribution that included many long-range connectivity changes. During performance of an experimental task that involved periodic painful stimulation, compared to saline, low-dose midazolam was associated with robust increases in functional connectivity. This finding was concordant across different seed-based analyses for midazolam, but not ketamine. The neuroimaging drug trial from which this data was drawn was pre-registered (NCT-02515890) prior to enrollment of the first subject.
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Affiliation(s)
- Keith M Vogt
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Pittsburgh, 3459 Fifth Avenue, UPMC Montefiore - Suite 467, Pittsburgh, PA, 15213, USA.
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, USA.
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA.
- Clinical and Translational Science Institute, University of Pittsburgh, Pittsburgh, PA, USA.
| | - James W Ibinson
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Pittsburgh, 3459 Fifth Avenue, UPMC Montefiore - Suite 467, Pittsburgh, PA, 15213, USA
- Department of Anesthesiology, Surgical Service Line, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, PA, USA
- Clinical and Translational Science Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Alex C Burlew
- School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - C Tyler Smith
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Pittsburgh, 3459 Fifth Avenue, UPMC Montefiore - Suite 467, Pittsburgh, PA, 15213, USA
| | - Howard J Aizenstein
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Julie A Fiez
- Center for the Neural Basis of Cognition, Pittsburgh, PA, USA
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
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Vogt KM, Pryor KO. Anesthesia and the neurobiology of fear and posttraumatic stress disorder. Curr Opin Anaesthesiol 2022; 35:593-599. [PMID: 35993581 PMCID: PMC9469898 DOI: 10.1097/aco.0000000000001176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
PURPOSE OF REVIEW Dysfunction of fear memory systems underlie a cluster of clinically important and highly prevalent psychological morbidities seen in perioperative and critical care patients, most archetypally posttraumatic stress disorder (PTSD). Several sedative-hypnotics and analgesics are known to modulate fear systems, and it is theoretically plausible that clinical decisions of the anesthesiologist could impact psychological outcomes. This review aims to provide a focused synthesis of relevant literature from multiple fields of research. RECENT FINDINGS There is evidence in some contexts that unconscious fear memory systems are less sensitive to anesthetics than are conscious memory systems. Opiates may suppress the activation of fear systems and have benefit in the prevention of PTSD following trauma. There is inconsistent evidence that the use of propofol and benzodiazepines for sedation following trauma may potentiate the development of PTSD relative to other drugs. The benefits of ketamine seen in the treatment of major depression are not clearly replicated in PTSD-cluster psychopathologies, and its effects on fear processes are complex. SUMMARY There are multiple theoretical mechanisms by which anesthetic drugs can modulate fear systems and clinically important fear-based psychopathologies. The current state of research provides some evidence to support further hypothesis investigation. However, the absence of effectiveness studies and the inconsistent signals from smaller studies provide insufficient evidence to currently offer firm clinical guidance.
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Affiliation(s)
- Keith M. Vogt
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh, School of Medicine
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh
- Center for the Neural Basis of Cognition
- Clinical and Translational Science Institute, University of Pittsburgh
| | - Kane O. Pryor
- Department of Anesthesiology, Weill Cornell Medicine
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Viana KA, Moterane MM, Green SM, Mason KP, Costa LR. Amnesia after Midazolam and Ketamine Sedation in Children: A Secondary Analysis of a Randomized Controlled Trial. J Clin Med 2021; 10:5430. [PMID: 34830712 PMCID: PMC8625279 DOI: 10.3390/jcm10225430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 11/13/2021] [Accepted: 11/16/2021] [Indexed: 11/16/2022] Open
Abstract
The incidence of peri-procedural amnesia following procedural sedation in children is unclear and difficult to determine. This study aimed to apply quantitative and qualitative approaches to better understand amnesia following dental sedation of children. After Institutional Review Board Approval, children scheduled for sedation for dental procedures with oral midazolam (OM), oral midazolam and ketamine (OMK), or intranasal midazolam and ketamine (IMK) were recruited for examination of peri-procedural amnesia. Amnesia during the dental session was assessed using a three-stage method, using identification of pictures and an animal toy. On the day following the sedation, primary caregivers answered two questions about their children's memory. One week later, the children received a semi-structured interview. Behavior and level of sedation during the dental session were recorded. Quantitative data were analyzed using descriptive statistics and comparison tests. Qualitative data were analyzed using content analysis. Triangulation was used. Thirty-five children (age: 36 to 76 months) participated in the quantitative analysis. Most children showed amnesia for the dental procedure (82.9%, n = 29/35) and remembered receiving the sedation (82.1%, n = 23/28 for oral administration; 59.3%, n = 16/27 for intranasal administration). The occurrence of amnesia for the dental procedure was slightly higher in the oral midazolam group compared with the other groups (44.8%, n = 13/29 for OM, 13.8%, n = 4/29 for OMK, and 41.4%, n = 12/29 for IMK). Twenty-eight children participated in the qualitative approach. The major theme identified was that some children could remember their procedures in detail. We conclude that peri-procedural amnesia of the dental procedure was common following sedation.
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Affiliation(s)
- Karolline A. Viana
- Dentistry Graduate Program, Faculdade de Odontologia, Universidade Federal de Goiás, Goiânia 74000-000, Goiás, Brazil;
| | - Mônica M. Moterane
- Dentistry Graduate Program, Faculdade de Odontologia, Universidade Federal de Goiás, Goiânia 74000-000, Goiás, Brazil;
| | - Steven M. Green
- Department of Emergency Medicine, Loma Linda University, Loma Linda, CA 92354, USA;
| | - Keira P. Mason
- Department of Anesthesiology, Critical Care and Pain Medicine, Harvard Medical School, Boston Children’s Hospital, Boston, MA 02115, USA;
| | - Luciane R. Costa
- Department of Oral Health, Faculdade de Odontologia, Universidade Federal de Goiás, Goiânia 74000-000, Goiás, Brazil;
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Mnemonic Discrimination Deficits in First-Episode Psychosis and a Ketamine Model Suggest Dentate Gyrus Pathology Linked to NMDA Receptor Hypofunction. BIOLOGICAL PSYCHIATRY: COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2021; 6:1185-1192. [PMID: 34649019 DOI: 10.1016/j.bpsc.2021.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 08/17/2021] [Accepted: 09/12/2021] [Indexed: 11/23/2022]
Abstract
BACKGROUND Converging evidence from neuroimaging and postmortem studies suggests that hippocampal subfields are differentially affected in schizophrenia. Recent studies report dentate gyrus dysfunction in chronic schizophrenia, but the underlying mechanisms remain to be elucidated. Here, we sought to examine if this deficit is already present in first-episode psychosis and if NMDA receptor hypofunction, a putative central pathophysiological mechanism in schizophrenia, experimentally induced by ketamine, would result in a similar abnormality. METHODS We applied a mnemonic discrimination task selectively taxing pattern separation in two experiments: 1) a group of 23 patients with first-episode psychosis and 23 matched healthy volunteers and 2) a group of 19 healthy volunteers before and during a ketamine challenge (0.27 mg/kg over 10 min, then 0.25 mg/kg/hour for 50 min, 0.01 mL/s). We calculated response bias-corrected pattern separation and recognition scores. We also examined the relationships between task performance and symptom severity as well as ketamine levels. RESULTS We reported a deficit in pattern separation performance in patients with first-episode psychosis compared with healthy volunteers (p = .04) and in volunteers during the ketamine challenge compared with baseline (p = .003). Pattern recognition was lower in patients with first-episode psychosis than in control subjects (p < .01). Exploratory analyses revealed no correlation between task performance and Repeatable Battery for the Assessment of Neuropsychological Status total scores or positive symptoms in patients with first-episode psychosis or with ketamine serum levels. CONCLUSIONS We observed a mnemonic discrimination deficit in both datasets. Our findings suggest a tentative mechanistic link between dentate gyrus dysfunction in first-episode psychosis and NMDA receptor hypofunction.
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