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Guo F, Zhang B, Shen F, Li Q, Song Y, Li T, Zhang Y, Du W, Li Y, Liu W, Cao H, Zhou X, Zheng Y, Zhu S, Li Y, Liu Z. Sevoflurane acts as an antidepressant by suppression of GluN2D-containing NMDA receptors on interneurons. Br J Pharmacol 2024; 181:3483-3502. [PMID: 38779864 DOI: 10.1111/bph.16420] [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] [Received: 04/16/2023] [Revised: 10/18/2023] [Accepted: 11/15/2023] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND AND PURPOSE Sevoflurane, a commonly used inhaled anaesthetic known for its favourable safety profile and rapid onset and offset, has not been thoroughly investigated as a potential treatment for depression. In this study, we reveal the mechanism through which sevoflurane delivers enduring antidepressant effects. EXPERIMENTAL APPROACH To assess the antidepressant effects of sevoflurane, behavioural tests were conducted, along with in vitro and ex vivo whole-cell patch-clamp recordings, to examine the effects on GluN1-GluN2 incorporated N-methyl-d-aspartate (NMDA) receptors (NMDARs) and neuronal circuitry in the medial prefrontal cortex (mPFC). Multiple-channel electrophysiology in freely moving mice was performed to evaluate sevoflurane's effects on neuronal activity, and GluN2D knockout (grin2d-/-) mice were used to confirm the requirement of GluN2D for the antidepressant effects. KEY RESULTS Repeated exposure to subanaesthetic doses of sevoflurane produced sustained antidepressant effects lasting up to 2 weeks. Sevoflurane preferentially inhibited GluN2C- and GluN2D-containing NMDARs, causing a reduction in interneuron activity. In contrast, sevoflurane increased action potentials (AP) firing and decreased spontaneous inhibitory postsynaptic current (sIPSC) in mPFC pyramidal neurons, demonstrating a disinhibitory effect. These effects were absent in grin2d-/- mice, and both pharmacological blockade and genetic knockout of GluN2D abolished sevoflurane's antidepressant actions, suggesting that GluN2D is essential for its antidepressant effect. CONCLUSION AND IMPLICATIONS Sevoflurane directly targets GluN2D, leading to a specific decrease in interneuron activity and subsequent disinhibition of pyramidal neurons, which may underpin its antidepressant effects. Targeting the GluN2D subunit could hold promise as a potential therapeutic strategy for treating depression.
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Affiliation(s)
- Fei Guo
- Shanghai Key Laboratory of Maternal Fetal Medicine, Shanghai Institute of Maternal-Fetal Medicine and Gynecologic Oncology, Department of Anesthesiology, Clinical and Translational Research Center, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Bing Zhang
- Shanghai Key Laboratory of Maternal Fetal Medicine, Shanghai Institute of Maternal-Fetal Medicine and Gynecologic Oncology, Department of Anesthesiology, Clinical and Translational Research Center, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
| | - Fuyi Shen
- Shanghai Key Laboratory of Maternal Fetal Medicine, Shanghai Institute of Maternal-Fetal Medicine and Gynecologic Oncology, Department of Anesthesiology, Clinical and Translational Research Center, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
| | - Qian Li
- Shanghai Key Laboratory of Maternal Fetal Medicine, Shanghai Institute of Maternal-Fetal Medicine and Gynecologic Oncology, Department of Anesthesiology, Clinical and Translational Research Center, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
| | - Yingcai Song
- Shanghai Key Laboratory of Maternal Fetal Medicine, Shanghai Institute of Maternal-Fetal Medicine and Gynecologic Oncology, Department of Anesthesiology, Clinical and Translational Research Center, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
| | - Tianyu Li
- Shanghai Key Laboratory of Maternal Fetal Medicine, Shanghai Institute of Maternal-Fetal Medicine and Gynecologic Oncology, Department of Anesthesiology, Clinical and Translational Research Center, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
| | - Yongmei Zhang
- University of Chinese Academy of Sciences, Beijing, China
| | - Weijia Du
- Shanghai Key Laboratory of Maternal Fetal Medicine, Shanghai Institute of Maternal-Fetal Medicine and Gynecologic Oncology, Department of Anesthesiology, Clinical and Translational Research Center, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
| | - Yuanxi Li
- Institute for Cognitive Neurodynamics, East China University of Science and Technology, Shanghai, China
| | - Wei Liu
- Shanghai Key Laboratory of Maternal Fetal Medicine, Shanghai Institute of Maternal-Fetal Medicine and Gynecologic Oncology, Department of Anesthesiology, Clinical and Translational Research Center, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
| | - Hang Cao
- Shanghai Key Laboratory of Maternal Fetal Medicine, Shanghai Institute of Maternal-Fetal Medicine and Gynecologic Oncology, Department of Anesthesiology, Clinical and Translational Research Center, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
| | - Xianjin Zhou
- Shanghai Key Laboratory of Maternal Fetal Medicine, Shanghai Institute of Maternal-Fetal Medicine and Gynecologic Oncology, Department of Anesthesiology, Clinical and Translational Research Center, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
| | - Yinli Zheng
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- School of Pharmacy, Anhui University of Chinese Medicine, Hefei, China
| | - Shujia Zhu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Yang Li
- Shanghai Key Laboratory of Maternal Fetal Medicine, Shanghai Institute of Maternal-Fetal Medicine and Gynecologic Oncology, Department of Anesthesiology, Clinical and Translational Research Center, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Zhiqiang Liu
- Shanghai Key Laboratory of Maternal Fetal Medicine, Shanghai Institute of Maternal-Fetal Medicine and Gynecologic Oncology, Department of Anesthesiology, Clinical and Translational Research Center, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
- Anesthesia and Brain Function Research Institute, Tongji University School of Medicine, Shanghai, China
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Rios RL, Green M, Smith SK, Kafashan M, Ching S, Farber NB, Lin N, Lucey BP, Reynolds CF, Lenze EJ, Palanca BJA. Propofol enhancement of slow wave sleep to target the nexus of geriatric depression and cognitive dysfunction: protocol for a phase I open label trial. BMJ Open 2024; 14:e087516. [PMID: 38816055 PMCID: PMC11138309 DOI: 10.1136/bmjopen-2024-087516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Accepted: 04/26/2024] [Indexed: 06/01/2024] Open
Abstract
INTRODUCTION Late-life treatment-resistant depression (LL-TRD) is common and increases risk for accelerated ageing and cognitive decline. Impaired sleep is common in LL-TRD and is a risk factor for cognitive decline. Slow wave sleep (SWS) has been implicated in key processes including synaptic plasticity and memory. A deficiency in SWS may be a core component of depression pathophysiology. The anaesthetic propofol can induce electroencephalographic (EEG) slow waves that resemble SWS. Propofol may enhance SWS and oral antidepressant therapy, but relationships are unclear. We hypothesise that propofol infusions will enhance SWS and improve depression in older adults with LL-TRD. This hypothesis has been supported by a recent small case series. METHODS AND ANALYSIS SWIPED (Slow Wave Induction by Propofol to Eliminate Depression) phase I is an ongoing open-label, single-arm trial that assesses the safety and feasibility of using propofol to enhance SWS in older adults with LL-TRD. The study is enrolling 15 English-speaking adults over age 60 with LL-TRD. Participants will receive two propofol infusions 2-6 days apart. Propofol infusions are individually titrated to maximise the expression of EEG slow waves. Preinfusion and postinfusion sleep architecture are evaluated through at-home overnight EEG recordings acquired using a wireless headband equipped with dry electrodes. Sleep EEG recordings are scored manually. Key EEG measures include sleep slow wave activity, SWS duration and delta sleep ratio. Longitudinal changes in depression, suicidality and anhedonia are assessed. Assessments are performed prior to the first infusion and up to 10 weeks after the second infusion. Cognitive ability is assessed at enrolment and approximately 3 weeks after the second infusion. ETHICS AND DISSEMINATION The study was approved by the Washington University Human Research Protection Office. Recruitment began in November 2022. Dissemination plans include presentations at scientific conferences, peer-reviewed publications and mass media. Positive results will lead to a larger phase II randomised placebo-controlled trial. TRIAL REGISTRATION NUMBER NCT04680910.
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Affiliation(s)
- Rachel Lynn Rios
- Department of Anesthesiology, Washington University School of Medicine in St. Louis, St Louis, Missouri, USA
| | - Michael Green
- Department of Anesthesiology, Washington University School of Medicine in St. Louis, St Louis, Missouri, USA
| | - S Kendall Smith
- Department of Anesthesiology, Washington University School of Medicine in St. Louis, St Louis, Missouri, USA
- Center on Biological Rhythms and Sleep, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - MohammadMehdi Kafashan
- Department of Anesthesiology, Washington University School of Medicine in St. Louis, St Louis, Missouri, USA
- Center on Biological Rhythms and Sleep, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - ShiNung Ching
- Department of Electrical & Systems Engineering, Washington University in St. Louis, St Louis, Missouri, USA
| | - Nuri B Farber
- Department of Psychiatry, Washington University School of Medicine in St. Louis, St Louis, Missouri, USA
| | - Nan Lin
- Department of Biostatistics and Data Science, Washington University in St Louis, St Louis, Missouri, USA
| | - Brendan P Lucey
- Center on Biological Rhythms and Sleep, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
- Department of Neurology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Charles F Reynolds
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Eric J Lenze
- Department of Anesthesiology, Washington University School of Medicine in St. Louis, St Louis, Missouri, USA
- Department of Psychiatry, Washington University School of Medicine in St. Louis, St Louis, Missouri, USA
| | - Ben Julian Agustin Palanca
- Department of Anesthesiology, Washington University School of Medicine in St. Louis, St Louis, Missouri, USA
- Center on Biological Rhythms and Sleep, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
- Department of Psychiatry, Washington University School of Medicine in St. Louis, St Louis, Missouri, USA
- Division of Biology and Biomedical Sciences, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA
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Loison V, Voskobiynyk Y, Lindquist B, Necula D, Longrois D, Paz J, Holcman D. Mapping general anesthesia states based on electro-encephalogram transition phases. Neuroimage 2024; 285:120498. [PMID: 38135170 PMCID: PMC10792552 DOI: 10.1016/j.neuroimage.2023.120498] [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] [Received: 05/17/2023] [Revised: 12/08/2023] [Accepted: 12/11/2023] [Indexed: 12/24/2023] Open
Abstract
Cortical electro-encephalography (EEG) served as the clinical reference for monitoring unconsciousness during general anesthesia. The existing EEG-based monitors classified general anesthesia states as underdosed, adequate, or overdosed, lacking predictive power due to the absence of transition phases among these states. In response to this limitation, we undertook an analysis of the EEG signal during isoflurane-induced general anesthesia in mice. Adopting a data-driven approach, we applied signal processing techniques to track θ- and δ-band dynamics, along with iso-electric suppressions. Combining this approach with machine learning, we successfully developed an automated algorithm. The findings of our study revealed that the dampening of the δ-band occurred several minutes before the onset of significant iso-electric suppression episodes. Furthermore, a distinct γ-frequency oscillation was observed, persisting for several minutes during the recovery phase subsequent to isoflurane-induced overdose. As a result of our research, we generated a map summarizing multiple brain states and their transitions, offering a tool for predicting and preventing overdose during general anesthesia. The transition phases identified, along with the developed algorithm, have the potential to be generalized, enabling clinicians to prevent inadequate anesthesia and, consequently, tailor anesthetic regimens to individual patients.
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Affiliation(s)
- V Loison
- Group of Data Modeling and Computational Biology, Institut de Biologie (IBENS), École Normale Supérieure CNRS, Université PSL Paris, France
| | - Y Voskobiynyk
- Gladstone Institutes, USA; Gladstone Institute of Neurological Disease, University of California, San Francisco, USA
| | - B Lindquist
- Gladstone Institutes, USA; Gladstone Institute of Neurological Disease, University of California, San Francisco, USA
| | - D Necula
- Gladstone Institutes, USA; Gladstone Institute of Neurological Disease, University of California, San Francisco, USA
| | - D Longrois
- Département d'Anesthésie-Réanimation, Hôpital Bichat-Claude Bernard, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - J Paz
- Gladstone Institutes, USA; Gladstone Institute of Neurological Disease, University of California, San Francisco, USA
| | - D Holcman
- Group of Data Modeling and Computational Biology, Institut de Biologie (IBENS), École Normale Supérieure CNRS, Université PSL Paris, France; DAMPT, University of Cambridge and Churchill College, CB30DS, Cambridge, UK.
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Mansouri MT, Ahmed MT, Cassim TZ, Kreuzer M, Graves MC, Fenzl T, García PS. Telemetric electroencephalography recording in anesthetized mice-A novel system using minimally-invasive needle electrodes with a wireless OpenBCI™ Cyton Biosensing Board. MethodsX 2023; 10:102187. [PMID: 37424756 PMCID: PMC10326441 DOI: 10.1016/j.mex.2023.102187] [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: 03/23/2023] [Accepted: 04/14/2023] [Indexed: 07/11/2023] Open
Abstract
Telemetric electroencephalography (EEG) recording, using subdermal needle electrodes, is a minimally-invasive method to investigate mammalian neurophysiology during anesthesia. These inexpensive systems may streamline experiments examining global brain phenomena during surgical anesthesia or disease. We utilized the OpenBCI™ Cyton board with subdermal needle electrodes to extract EEG features in six C57BL/6J mice undergoing isoflurane anesthesia. Burst suppression ratio (BSR) and spectral features were compared for a verification of our method. Following an increase from 1.5% to 2.0% isoflurane, the BSR increased (Wilcoxon-signed-rank statistic; p = 0.0313). Furthermore, although the absolute EEG spectral power decreased, the relative spectral power remained comparable (Wilcoxon-Mann-Whitney U-Statistic; 95% CI exclusive AUC=0.5; p < 0.05). Compared to tethered systems, this method confers several improvements for anesthesia specific protocols: 1-Avoiding electrode implant surgical procedures, 2-Anatomical non-specificity for needle electrode placement to monitor global cortical activity representative of anesthetic state, 3-Facility to repeat recordings in the same animal, 4-User-friendly for non-experts, 5-Rapid set-up time, and 6-Lower costs.•Minimally-invasive telemetric EEG recording systems ergonomically improve tethered systems for anesthesia protocols.•Using this method, we verified that higher isoflurane concentrations resulted in an increased EEG burst suppression ratio and decreased EEG absolute spectral power, with no change in frequency distribution.
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Affiliation(s)
- Mohammad T. Mansouri
- Department of Anesthesiology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Meah T. Ahmed
- Department of Anesthesiology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Tuan Z. Cassim
- Department of Anesthesiology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Matthias Kreuzer
- Department of Anaesthesiology & Intensive Care, School of Medicine, Technical University of Munich, Munich, Germany
| | - Morgan C. Graves
- Department of Anesthesiology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Thomas Fenzl
- Department of Anaesthesiology & Intensive Care, School of Medicine, Technical University of Munich, Munich, Germany
| | - Paul S. García
- Department of Anesthesiology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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Manzella FM, Cabrera OH, Wilkey D, Fine-Raquet B, Klawitter J, Krishnan K, Covey DF, Jevtovic-Todorovic V, Todorovic SM. Sex-specific hypnotic effects of the neuroactive steroid (3β,5β,17β)-3-hydroxyandrostane-17-carbonitrile are mediated by peripheral metabolism into an active hypnotic steroid. Br J Anaesth 2023; 130:154-164. [PMID: 36428160 PMCID: PMC10080470 DOI: 10.1016/j.bja.2022.09.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 08/01/2022] [Accepted: 09/24/2022] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND The novel synthetic neuroactive steroid (3β,5β,17β)-3-hydroxyandrostane-17-carbonitrile (3β-OH) blocks T-type calcium channels but does not directly modulate neuronal γ-aminobutyric acid type A (GABAA) currents like other anaesthetic neurosteroids. As 3β-OH has sex-specific hypnotic effects in adult rats, we studied the mechanism contributing to sex differences in its effects. METHODS We used a combination of behavioural loss of righting reflex, neuroendocrine, pharmacokinetic, in vitro patch-clamp electrophysiology, and in vivo electrophysiological approaches in wild-type mice and in genetic knockouts of the CaV3.1 T-type calcium channel isoform to study the mechanisms by which 3β-OH and its metabolite produces sex-specific hypnotic effects. RESULTS Adult male mice were less sensitive to the hypnotic effects of 3β-OH compared with female mice, and these differences appeared during development. Adult males had higher 3β-OH brain concentrations despite being less sensitive to its hypnotic effects. Females metabolised 3β-OH into the active GABAA receptor positive allosteric modulator (3α,5β,17β)-3-hydroxyandrostane-17-carbonitrile (3α-OH) to a greater extent than males. The 3α-OH metabolite has T-channel blocking properties with sex-specific hypnotic and pharmacokinetic effects. Sex-dependent suppression of the cortical electroencephalogram is more pronounced with 3α-OH compared with 3β-OH. CONCLUSIONS The sex-specific differences in the hypnotic effect of 3β-OH in mice are attributable to differences in its peripheral metabolism into the more potent hypnotic metabolite 3α-OH.
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Affiliation(s)
- Francesca M Manzella
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Omar H Cabrera
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Davis Wilkey
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Brier Fine-Raquet
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Jelena Klawitter
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Kathiresan Krishnan
- Department of Developmental Biology, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Douglas F Covey
- Department of Developmental Biology, Washington University in St. Louis School of Medicine, St. Louis, MO, USA; Taylor Family Institute for Innovative Psychiatric Research, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Vesna Jevtovic-Todorovic
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Slobodan M Todorovic
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
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Motyl CM, Beck AW. Strategies for prevention and treatment of spinal cord ischemia during F/BEVAR. Semin Vasc Surg 2022; 35:297-305. [DOI: 10.1053/j.semvascsurg.2022.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/22/2022] [Accepted: 06/27/2022] [Indexed: 11/11/2022]
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Neonatal Anesthesia and Oxidative Stress. Antioxidants (Basel) 2022; 11:antiox11040787. [PMID: 35453473 PMCID: PMC9026345 DOI: 10.3390/antiox11040787] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/13/2022] [Accepted: 04/14/2022] [Indexed: 02/04/2023] Open
Abstract
Neonatal anesthesia, while often essential for surgeries or imaging procedures, is accompanied by significant risks to redox balance in the brain due to the relatively weak antioxidant system in children. Oxidative stress is characterized by concentrations of reactive oxygen species (ROS) that are elevated beyond what can be accommodated by the antioxidant defense system. In neonatal anesthesia, this has been proposed to be a contributing factor to some of the negative consequences (e.g., learning deficits and behavioral abnormalities) that are associated with early anesthetic exposure. In order to assess the relationship between neonatal anesthesia and oxidative stress, we first review the mechanisms of action of common anesthetic agents, the key pathways that produce the majority of ROS, and the main antioxidants. We then explore the possible immediate, short-term, and long-term pathways of neonatal-anesthesia-induced oxidative stress. We review a large body of literature describing oxidative stress to be evident during and immediately following neonatal anesthesia. Moreover, our review suggests that the short-term pathway has a temporally limited effect on oxidative stress, while the long-term pathway can manifest years later due to the altered development of neurons and neurovascular interactions.
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Ward-Flanagan R, Lo AS, Clement EA, Dickson CT. A Comparison of Brain-State Dynamics across Common Anesthetic Agents in Male Sprague-Dawley Rats. Int J Mol Sci 2022; 23:ijms23073608. [PMID: 35408973 PMCID: PMC8998244 DOI: 10.3390/ijms23073608] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/11/2022] [Accepted: 03/21/2022] [Indexed: 02/04/2023] Open
Abstract
Anesthesia is a powerful tool in neuroscientific research, especially in sleep research where it has the experimental advantage of allowing surgical interventions that are ethically problematic in natural sleep. Yet, while it is well documented that different anesthetic agents produce a variety of brain states, and consequently have differential effects on a multitude of neurophysiological factors, these outcomes vary based on dosages, the animal species used, and the pharmacological mechanisms specific to each anesthetic agent. Thus, our aim was to conduct a controlled comparison of spontaneous electrophysiological dynamics at a surgical plane of anesthesia under six common research anesthetics using a ubiquitous animal model, the Sprague-Dawley rat. From this direct comparison, we also evaluated which anesthetic agents may serve as pharmacological proxies for the electrophysiological features and dynamics of unconscious states such as sleep and coma. We found that at a surgical plane, pentobarbital, isoflurane and propofol all produced a continuous pattern of burst-suppression activity, which is a neurophysiological state characteristically observed during coma. In contrast, ketamine-xylazine produced synchronized, slow-oscillatory activity, similar to that observed during slow-wave sleep. Notably, both urethane and chloral hydrate produced the spontaneous, cyclical alternations between forebrain activation (REM-like) and deactivation (non-REM-like) that are similar to those observed during natural sleep. Thus, choice of anesthesia, in conjunction with continuous brain state monitoring, are critical considerations in order to avoid brain-state confounds when conducting neurophysiological experiments.
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Affiliation(s)
- Rachel Ward-Flanagan
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2E1, Canada; (R.W.-F.); (E.A.C.)
| | - Alto S. Lo
- Department of Psychology, University of Alberta, Edmonton, AB T6G 2R3, Canada;
| | - Elizabeth A. Clement
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2E1, Canada; (R.W.-F.); (E.A.C.)
| | - Clayton T. Dickson
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2E1, Canada; (R.W.-F.); (E.A.C.)
- Department of Psychology, University of Alberta, Edmonton, AB T6G 2R3, Canada;
- Department of Physiology, University of Alberta, Edmonton, AB T6G 2H7, Canada
- Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB T6G 2G3, Canada
- Correspondence: ; Tel.: +1-(780)-492-7860
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Evaluation of Anesthetic Specific EEG Dynamics during State Transitions between Loss and Return of Responsiveness. Brain Sci 2021; 12:brainsci12010037. [PMID: 35053781 PMCID: PMC8773581 DOI: 10.3390/brainsci12010037] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 12/21/2021] [Accepted: 12/23/2021] [Indexed: 11/17/2022] Open
Abstract
Purpose: electroencephalographic (EEG) information is used to monitor the level of cortical depression of a patient undergoing surgical intervention under general anesthesia. The dynamic state transitions into and out of anesthetic-induced loss and return of responsiveness (LOR, ROR) present a possibility to evaluate the dynamics of the EEG induced by different substances. We evaluated changes in the EEG power spectrum during anesthesia emergence for three different anesthetic regimens. We also assessed the possible impact of these changes on processed EEG parameters such as the permutation entropy (PeEn) and the cerebral state index (CSI). Methods: we analyzed the EEG from 45 patients, equally assigned to three groups. All patients were induced with propofol and the groups differed by the maintenance anesthetic regimen, i.e., sevoflurane, isoflurane, or propofol. We evaluated the EEG and parameter dynamics during LOR and ROR. For the emergence period, we focused on possible differences in the EEG dynamics in the different groups. Results: depending on the substance, the EEG emergence patterns showed significant differences that led to a substance-specific early activation of higher frequencies as indicated by the “wake” CSI values that occurred minutes before ROR in the inhalational anesthetic groups. Conclusion: our results highlight substance-specific differences in the emergence from anesthesia that can influence the EEG-based monitoring that probably have to be considered in order to improve neuromonitoring during general anesthesia.
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Ma K, Bebawy JF. Electroencephalographic Burst-Suppression, Perioperative Neuroprotection, Postoperative Cognitive Function, and Mortality: A Focused Narrative Review of the Literature. Anesth Analg 2021; 135:79-90. [PMID: 34871183 DOI: 10.1213/ane.0000000000005806] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Burst-suppression is an electroencephalographic pattern that results from a diverse array of pathophysiological causes and/or metabolic neuronal suppression secondary to the administration of anesthetic medications. The purpose of this review is to provide an overview of the physiological mechanisms that underlie the burst-suppression pattern and to present in a comprehensive way the available evidence both supporting and in opposition to the clinical use of this electroencephalographic pattern as a therapeutic measure in various perioperative settings.
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Affiliation(s)
- Kan Ma
- From the *Department of Anesthesiology and Pain Medicine, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
| | - John F Bebawy
- Department of Anesthesiology & Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois
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Jing Z, Pecka M, Grothe B. Ketamine-xylazine anesthesia depth affects auditory neuronal responses in the lateral superior olive complex of the gerbil. J Neurophysiol 2021; 126:1660-1669. [PMID: 34644166 DOI: 10.1152/jn.00217.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Studies of in vivo neuronal responses to auditory inputs in the superior olive complex (SOC) are usually done under anesthesia. However, little attention has been paid to the effect of anesthesia itself on response properties. Here, we assessed the effect of anesthesia depth under ketamine-xylazine anesthetics on auditory evoked response properties of lateral SOC neurons. Anesthesia depth was tracked by monitoring EEG spectral peak frequencies. An increase in anesthesia depth led to a decrease of spontaneous discharge activities and an elevated response threshold. The temporal responses to suprathreshold tones were also affected, with adapted responses reduced but peak responses unaffected. Deepening the anesthesia depth also increased first spike latency. However, spike jitter was not affected. Auditory brainstem responses to clicks confirmed that ketamine-xylazine anesthesia depth affects auditory neuronal activities and the effect on spike rate and spike timing persists through the auditory pathway. We concluded from those observations that ketamine-xylazine affects lateral SOC response properties depending on the anesthesia depth.NEW & NOTEWORTHY We studied how the depth of ketamine-xylazine anesthesia altered response properties of lateral superior olive complex neurons, and auditory brainstem evoked responses. Our results provide direct evidence that anesthesia depth affects auditory neuronal responses and reinforce the notion that both the anesthetics and the anesthesia depth should be considered when interpreting/comparing in vivo neuronal recordings.
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Affiliation(s)
- Zhizi Jing
- Division of Neurobiology, Department of Biology II, Ludwig Maximilian University of Munich, Martinsried, Germany
| | - Michael Pecka
- Division of Neurobiology, Department of Biology II, Ludwig Maximilian University of Munich, Martinsried, Germany
| | - Benedikt Grothe
- Division of Neurobiology, Department of Biology II, Ludwig Maximilian University of Munich, Martinsried, Germany
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Joksimovic SM, Sampath D, Krishnan K, Covey DF, Jevtovic-Todorovic V, Raol YH, Todorovic SM. Differential effects of the novel neurosteroid hypnotic (3β,5β,17β)-3-hydroxyandrostane-17-carbonitrile on electroencephalogram activity in male and female rats. Br J Anaesth 2021; 127:435-446. [PMID: 33972091 PMCID: PMC8451239 DOI: 10.1016/j.bja.2021.03.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 03/01/2021] [Accepted: 03/03/2021] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND We recently showed that a neurosteroid analogue, (3β,5β,17β)-3-hydroxyandrostane-17-carbonitrile (3β-OH), induced hypnosis in rats. The aim of the present study was to evaluate the hypnotic and anaesthetic potential of 3β-OH further using electroencephalography. METHODS We used behavioural assessment and cortical electroencephalogram (EEG) spectral power analysis to examine hypnotic and anaesthetic effects of 3β-OH (30 and 60 mg kg-1) administered intraperitoneally or intravenously to young adult male and female rats. RESULTS We found dose-dependent sex differences in 3β-OH-induced hypnosis and EEG changes. Both male and female rats responded similarly to i.p. 3β-OH 30 mg kg-1. However, at the higher dose (60 mg kg-1, i.p.), female rats had two-fold longer duration of spontaneous immobility than male rats (203.4 [61.6] min vs 101.3 [32.1] min), and their EEG was suppressed in the low-frequency range (2-6 Hz), in contrast to male rats. Although a sex-dependent hypnotic effect was not confirmed after 30 mg kg-1 i.v., female rats appeared more sensitive to 3β-OH with relatively small changes within delta (1-4 Hz) and alpha (8-13 Hz) bands. Finally, 3β-OH had a rapid onset of action and potent hypnotic/anaesthetic effect after 60 mg kg-1 i.v. in rats of both sexes; however, all female rats and only half of the male rats reached burst suppression, an EEG pattern usually associated with profound inhibition of thalamocortical networks. CONCLUSIONS Based on its behavioural effects and EEG signature, 3β-OH is a potent hypnotic in rats, with female rats being more sensitive than male rats.
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Affiliation(s)
- Srdjan M Joksimovic
- Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA.
| | - Dayalan Sampath
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University System, College Station, TX, USA
| | - Kathiresan Krishnan
- Department of Developmental Biology, Washington University School of Medicine, St Louis, MO, USA
| | - Douglas F Covey
- Department of Developmental Biology, Washington University School of Medicine, St Louis, MO, USA; Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St Louis, MO, USA
| | - Vesna Jevtovic-Todorovic
- Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Yogendra H Raol
- Department of Pediatrics, Division of Neurology, Translational Epilepsy Research Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Slobodan M Todorovic
- Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA; Neuroscience Graduate Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
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Moody OA, Vincent KF, Solt K. Sex, drugs, and anaesthesia research. Br J Anaesth 2021; 127:340-343. [PMID: 34330415 DOI: 10.1016/j.bja.2021.06.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 06/18/2021] [Accepted: 06/19/2021] [Indexed: 11/29/2022] Open
Abstract
In this issue of the British Journal of Anaesthesia, Joksimovic and colleagues report significant sex differences in sensitivity to the behavioural and neurophysiological effects of 3β-OH, a novel neurosteroid anesthetic. Female rats were more sensitive to the effects of 3β-OH than male rats, although the mechanims remain unclear. Sex differences have been understudied in anaesthesia research, and this article by Joksimovic and colleagues emphasizes the need to devote more effort to understanding these differences.
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Affiliation(s)
- Olivia A Moody
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Department of Anaesthesia, Harvard Medical School, Boston, MA, USA
| | - Kathleen F Vincent
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Department of Anaesthesia, Harvard Medical School, Boston, MA, USA
| | - Ken Solt
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Department of Anaesthesia, Harvard Medical School, Boston, MA, USA.
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Gui S, Li J, Li M, Shi L, Lu J, Shen S, Li P, Mei W. Revealing the Cortical Glutamatergic Neural Activity During Burst Suppression by Simultaneous wide Field Calcium Imaging and Electroencephalography in Mice. Neuroscience 2021; 469:110-124. [PMID: 34237388 DOI: 10.1016/j.neuroscience.2021.06.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 06/26/2021] [Accepted: 06/28/2021] [Indexed: 10/20/2022]
Abstract
Burst suppression (BS) is an electroencephalogram (EEG) pattern in which signals alternates between high-amplitude slow waves (burst waves) and nearly flat low-amplitude waves (suppression waves). In this study, we used wide-field (8.32 mm × 8.32 mm) fluorescent calcium imaging to record the activity of glutamatergic neurons in the parietal and occipital cortex, in conjunction with EEG recordings under BS induced by different anesthetics (sevoflurane, isoflurane, and propofol), to investigate the spatiotemporal pattern of neural activity under BS. The calcium signal of all observed cortices was decreased during the phase of EEG suppression. However, during the phase of EEG burst, the calcium signal in areas of the medial cortex, such as the secondary motor and retrosplenial area, was excited, whereas the signal in areas of the lateral cortex, such as the hindlimb cortex, forelimb cortex, barrel field, and primary visual area, was still suppressed or only weakly excited. Correlation analysis showed a strong correlation between the EEG signal and the calcium signal in the medial cortex under BS (except for propofol induced signals). As the burst-suppression ratio (BSR) increased, the regions with strong correlation coefficients became smaller, but strong correlation coefficients were still noted in the medial cortex. Taken together, our results reveal the landscape of cortical activity underlying BS.
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Affiliation(s)
- Shen Gui
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Jiayan Li
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Miaowen Li
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Liang Shi
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Jinling Lu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Shiqian Shen
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital/Harvard Medical School, 55 Fruit St, Boston, MA 02121, United States
| | - Pengcheng Li
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; HUST-Suzhou Institute for Brainsmatics, Suzhou, Jiangsu 215125, China.
| | - Wei Mei
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
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Shanker A, Abel JH, Schamberg G, Brown EN. Etiology of Burst Suppression EEG Patterns. Front Psychol 2021; 12:673529. [PMID: 34177731 PMCID: PMC8222661 DOI: 10.3389/fpsyg.2021.673529] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 05/14/2021] [Indexed: 12/14/2022] Open
Abstract
Burst-suppression electroencephalography (EEG) patterns of electrical activity, characterized by intermittent high-power broad-spectrum oscillations alternating with isoelectricity, have long been observed in the human brain during general anesthesia, hypothermia, coma and early infantile encephalopathy. Recently, commonalities between conditions associated with burst-suppression patterns have led to new insights into the origin of burst-suppression EEG patterns, their effects on the brain, and their use as a therapeutic tool for protection against deleterious neural states. These insights have been further supported by advances in mechanistic modeling of burst suppression. In this Perspective, we review the origins of burst-suppression patterns and use recent insights to weigh evidence in the controversy regarding the extent to which burst-suppression patterns observed during profound anesthetic-induced brain inactivation are associated with adverse clinical outcomes. Whether the clinical intent is to avoid or maintain the brain in a state producing burst-suppression patterns, monitoring and controlling neural activity presents a technical challenge. We discuss recent advances that enable monitoring and control of burst suppression.
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Affiliation(s)
- Akshay Shanker
- Department of Anesthesiology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
- Department of Anesthesia, Critical Care, and Pain Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United States
| | - John H. Abel
- Massachusetts Institute of Technology, Picower Institute for Learning and Memory, Cambridge, MA, United States
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, United States
- Division of Sleep Medicine, Harvard Medical School, Boston, MA, United States
| | - Gabriel Schamberg
- Massachusetts Institute of Technology, Picower Institute for Learning and Memory, Cambridge, MA, United States
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, United States
| | - Emery N. Brown
- Massachusetts Institute of Technology, Picower Institute for Learning and Memory, Cambridge, MA, United States
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, United States
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Yang B, Ao Y, Liu Y, Zhang X, Li Y, Tang F, Xu H. Activation of Dopamine Signals in the Olfactory Tubercle Facilitates Emergence from Isoflurane Anesthesia in Mice. Neurochem Res 2021; 46:1487-1501. [PMID: 33710536 DOI: 10.1007/s11064-021-03291-4] [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] [Received: 01/11/2021] [Revised: 02/22/2021] [Accepted: 02/26/2021] [Indexed: 11/28/2022]
Abstract
Activation of dopamine (DA) neurons is essential for the transition from sleep to wakefulness and maintenance of awakening, and sufficient to accelerate the emergence from general anesthesia in animals. Dopamine receptors (DR) are involve in arousal mediation. In the present study, we showed that the olfactory tubercle (OT) was active during emergence from isoflurane anesthesia, local injection of dopamine D1 receptor (D1R) agonist chloro-APB (1 mg/mL) and D2 receptor (D2R) agonist quinpirole (1 mg/mL) into OT enhanced behavioural and cortical arousal from isoflurane anesthesia, while D1R antagonist SCH-23390 (1 mg/mL) and D2R antagonist raclopride (2.5 mg/mL) prolonged recovery time. Optogenetic activation of DAergic terminals in OT also promoted behavioural and cortical arousal from isoflurane anesthesia. However, neither D1R/D2R agonists nor D1R/D2R antagonists microinjection had influences on the induction of isoflurane anesthesia. Optogenetic stimulation on DAergic terminals in OT also had no impact on the anesthesia induction. Our results indicated that DA signals in OT accelerated emergence from isoflurane anesthesia. Furthermore, the induction of general anesthesia, different from the emergence process, was not mediated by the OT DAergic pathways.
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Affiliation(s)
- Bo Yang
- Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430071, People's Republic of China
| | - Yawen Ao
- Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430071, People's Republic of China
| | - Ying Liu
- Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430071, People's Republic of China
| | - Xuefen Zhang
- Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430071, People's Republic of China
| | - Ying Li
- Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430071, People's Republic of China
| | - Fengru Tang
- Radiation Physiology Laboratory, Singapore Nuclear Research and Safety Initiative, National University of Singapore, Singapore, Singapore
| | - Haibo Xu
- Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430071, People's Republic of China.
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Aksenov DP. Normal Development of Local Neurovascular Interactions and the Diagnostic Value of Resting State Functional MRI in Neurovascular Deficiency Based on the Example of Neonatal Anesthesia Exposure. Front Neurol 2021; 12:664706. [PMID: 33995262 PMCID: PMC8116565 DOI: 10.3389/fneur.2021.664706] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/08/2021] [Indexed: 01/25/2023] Open
Affiliation(s)
- Daniil P Aksenov
- Department of Radiology, NorthShore University HealthSystem, Evanston, IL, United States.,Department of Anesthesiology, NorthShore University HealthSystem, Evanston, IL, United States
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Nucleus accumbens neurons expressing dopamine D1 receptors modulate states of consciousness in sevoflurane anesthesia. Curr Biol 2021; 31:1893-1902.e5. [PMID: 33705720 DOI: 10.1016/j.cub.2021.02.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 12/18/2020] [Accepted: 02/04/2021] [Indexed: 11/22/2022]
Abstract
Although general anesthesia (GA) enables patients to undergo surgery without consciousness, the precise neural mechanisms underlying this phenomenon have yet to be identified. In addition to many studies over the past two decades implicating the thalamus, cortex, brainstem, and conventional sleep-wake circuits in GA-induced loss of consciousness (LOC), some recent studies have begun to highlight the importance of other brain areas as well. Here, we found that population activities of neurons expressing dopamine D1 receptor (D1R) in the nucleus accumbens (NAc), a critical interface between the basal ganglia and limbic system, began to decrease before sevoflurane-induced LOC and gradually returned after recovery of consciousness (ROC). Chemogenetic activation of NAcD1R neurons delayed induction of and accelerated emergence from sevoflurane GA, whereas chemogenetic inhibition of NAcD1R neurons exerted opposite effects. Moreover, transient activation of NAcD1R neurons induced significant cortical activation and behavioral emergence during continuous steady-state GA with sevoflurane or deep anesthesia state with constant and stable burst-suppression oscillations. Taken together, our findings uncover that NAcD1R neurons modulated states of consciousness associated with sevoflurane GA and may represent an area for targeting GA-induced changes in consciousness and ameliorating related adverse effects.
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Taharabaru S, Tamura T, Higashi M, Matsuda N, Satomoto M, Adachi YU, Sato AB, Okuda M. JM-1232(-) and propofol, a new combination of hypnotics with short-acting and non-cumulative preferable properties. Exp Anim 2021; 70:101-107. [PMID: 33071272 PMCID: PMC7887627 DOI: 10.1538/expanim.20-0071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 09/10/2020] [Indexed: 10/31/2022] Open
Abstract
Drug interactions are significant in anesthesiology because drug combinations can potentially possess novel properties. The pharmacological advantages of a new combination of the benzodiazepine receptor agonist JM-1232(-) and propofol were investigated in mice. Male adult mice were administered JM-1232(-) or propofol or combinations of the two drugs intravenously. Loss of the righting reflex was evaluated as achieving hypnosis, and the time until recovery of the reflex was measured as hypnosis time. After determining the ED50, doses double and triple the ED50 of propofol were injected with JM-1232(-) to compare hypnosis time. The injections were repeated four times, and the hypnosis times were compared. Flumazenil was administered separately immediately after the last dose was injected. The ED50 values ([95% confidence interval]) for hypnosis were 3.76 [3.36-4.10] for JM-1232(-) and 9.88 [8.03-11.58] mg kg-1 for propofol. Co-administration of 0.5 and 1 mg kg-1 JM-1232(-) reduced the ED50 values of propofol to 1.76 [1.21-2.51] and 1.00 [0.46-1.86] mg kg-1, respectively. The drug combination for hypnosis produced a supra-additive interaction. Hypnosis time was significantly shorter in the groups given the mixtures compared to each hypnotic administered alone. After repeated injections, hypnosis time with the mixtures showed smaller prolongation than that with the hypnotic alone. Flumazenil completely restored the recovery time after anesthesia. The combination of JM-1232(-) and propofol showed a supra-additive interaction, and the reduced hypnotic dose contributed to a faster recovery even after multiple injections.
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Affiliation(s)
- Saori Taharabaru
- Department of Anesthesia, Nishio Municipal Hospital, Nishio Municipal Hospital, 6 Kamiawahara, Kumami-cho, Nishio, Aichi 4458510, Japan
- Department of Anesthesiology, Aichi Gakuin University School of Dentistry, 2-11 Suemori-dori, Chikusa-ku, Nagoya, Aichi 4658651, Japan
| | - Takahiro Tamura
- Department of Surgical Intensive Care Medicine, Nagoya University Hospital, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi 4668550, Japan
| | - Michiko Higashi
- Department of Emergency & Critical Care Medicine, Nagoya University Graduate School of Medicine, Nagoya University Hospital, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi 4668550, Japan
| | - Naoyuki Matsuda
- Department of Emergency & Critical Care Medicine, Nagoya University Graduate School of Medicine, Nagoya University Hospital, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi 4668550, Japan
| | - Maiko Satomoto
- Department of Anesthesiology, Toho University School of Medicine, Toho University Medical Center, Ohmori Hospital, 6-11-1 Ohmori-Nishi, Ohta-ku, Tokyo 1438541, Japan
| | - Yushi U Adachi
- Department of Anesthesia and Intensive Care Medicine, International University of Health and Welfare, 537-3 Iguchi, Nasushiobara, Tochigi 3292763, Japan
| | - Aiji Boku Sato
- Department of Anesthesiology, Aichi Gakuin University School of Dentistry, 2-11 Suemori-dori, Chikusa-ku, Nagoya, Aichi 4658651, Japan
| | - Masahiro Okuda
- Department of Anesthesiology, Aichi Gakuin University School of Dentistry, 2-11 Suemori-dori, Chikusa-ku, Nagoya, Aichi 4658651, Japan
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Kratzer S, Schneider M, Obert DP, Schneider G, García PS, Kreuzer M. Age-Related EEG Features of Bursting Activity During Anesthetic-Induced Burst Suppression. Front Syst Neurosci 2020; 14:599962. [PMID: 33343307 PMCID: PMC7744408 DOI: 10.3389/fnsys.2020.599962] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 11/09/2020] [Indexed: 12/19/2022] Open
Abstract
Electroencephalographic (EEG) Burst Suppression (BSUPP) is a discontinuous pattern characterized by episodes of low voltage disrupted by bursts of cortical synaptic activity. It can occur while delivering high-dose anesthesia. Current research suggests an association between BSUPP and the occurrence of postoperative delirium in the post-anesthesia care unit (PACU) and beyond. We investigated burst micro-architecture to further understand how age influences the neurophysiology of this pharmacologically-induced state. We analyzed a subset of EEG recordings (n = 102) taken from a larger data set previously published. We selected the initial burst that followed a visually identified “silent second,” i.e., at least 1 s of iso-electricity of the EEG during propofol induction. We derived the (normalized) power spectral density [(n)PSD], the alpha band power, the maximum amplitude, the maximum slope of the EEG as well as the permutation entropy (PeEn) for the first 1.5 s of the initial burst of each patient. In the old patients >65 years, we observed significantly lower (p < 0.001) EEG power in the 1–15 Hz range. In general, their EEG contained a significantly higher amount of faster oscillations (>15 Hz). Alpha band power (p < 0.001), EEG amplitude (p = 0.001), and maximum EEG slope (p = 0.045) all significantly decreased with age, whereas PeEn increased (p = 0.008). Hence, we can describe an age-related change in features during EEG burst suppression. Sub-group analysis revealed no change in results based on pre-medication. These EEG changes add knowledge to the impact of age on cortical synaptic activity. In addition to a reduction in EEG amplitude, age-associated burst features can complicate the identification of excessive anesthetic administration in patients under general anesthesia. Knowledge of these neurophysiologic changes may not only improve anesthesia care through improved detection of burst suppression but might also provide insight into changes in neuronal network organization in patients at risk for age-related neurocognitive problems.
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Affiliation(s)
- Stephan Kratzer
- Department of Anesthesiology and Intensive Care Medicine, School of Medicine, Technical University Munich, Munich, Germany
| | - Michael Schneider
- Department of Anesthesiology and Intensive Care Medicine, School of Medicine, Technical University Munich, Munich, Germany
| | - David P Obert
- Department of Anesthesiology and Intensive Care Medicine, School of Medicine, Technical University Munich, Munich, Germany
| | - Gerhard Schneider
- Department of Anesthesiology and Intensive Care Medicine, School of Medicine, Technical University Munich, Munich, Germany
| | - Paul S García
- Department of Anesthesiology, Columbia University, New York, NY, United States
| | - Matthias Kreuzer
- Department of Anesthesiology and Intensive Care Medicine, School of Medicine, Technical University Munich, Munich, Germany
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Hannan S, Faulkner M, Aristovich K, Avery J, Walker MC, Holder DS. Optimised induction of on-demand focal hippocampal and neocortical seizures by electrical stimulation. J Neurosci Methods 2020; 346:108911. [DOI: 10.1016/j.jneumeth.2020.108911] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/10/2020] [Accepted: 08/12/2020] [Indexed: 11/25/2022]
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Fox AP, Wagner KR, Towle VL, Xie KG, Xie Z. Caffeine reverses the unconsciousness produced by light anesthesia in the continued presence of isoflurane in rats. PLoS One 2020; 15:e0241818. [PMID: 33152041 PMCID: PMC7643991 DOI: 10.1371/journal.pone.0241818] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 10/20/2020] [Indexed: 12/17/2022] Open
Abstract
Currently no drugs are employed clinically to reverse the unconsciousness induced by general anesthetics. Our previous studies showed that caffeine, when given near the end of an anesthesia session, accelerated emergence from isoflurane anesthesia, likely caused by caffeine’s ability to elevate intracellular cAMP levels and to block adenosine receptors. These earlier studies showed that caffeine did not rouse either rats or humans from deep anesthesia (≥ 1 minimum alveolar concentration, MAC). In this current crossover study, we examined whether caffeine reversed the unconsciousness produced by light anesthesia (< 1 MAC) in the continued presence of isoflurane. The primary endpoint of this study was to measure isoflurane levels at the time of recovery of righting reflex, which was a proxy for consciousness. Rats were deeply anesthetized with 2% isoflurane (~1.5 MAC) for 20 minutes. Subsequently, isoflurane was reduced to 1.2% for 10 minutes, then by 0.2% every 10 min; animals were monitored until the recovery of righting reflex occurred, in the continued presence of isoflurane. Respiration rate, heart rate and electroencephalogram (EEG) were monitored. Our results show that caffeine-treated rats recovered their righting reflex at a significantly higher inspired isoflurane concentration, corresponding to light anesthesia, than the same rats treated with saline (control). Respiration rate and heart rate increased initially after caffeine injection but were then unchanged for the rest of the anesthesia session. Deep anesthesia is correlated with burst suppression in EEG recordings. Our data showed that caffeine transiently reduced the burst suppression time produced by deep anesthesia, suggesting that caffeine altered neuronal circuit function but not to a point where it caused arousal. In contrast, under light anesthesia, caffeine shifted the EEG power to high frequency beta and gamma bands. These data suggest that caffeine may represent a clinically viable drug to reverse the unconsciousness produced by light anesthesia.
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Affiliation(s)
- Aaron P. Fox
- Department of Neurobiology, Pharmacology and Physiology, The University of Chicago, Chicago, Illinois, United States of America
| | - Kyle R. Wagner
- Department of Anesthesia and Critical Care, The University of Chicago, Chicago, Illinois, United States of America
| | - Vernon L. Towle
- Department of Neurology, The University of Chicago, Chicago, Illinois, United States of America
| | - Kelvin G. Xie
- Department of Neurobiology, Pharmacology and Physiology, The University of Chicago, Chicago, Illinois, United States of America
| | - Zheng Xie
- Department of Anesthesia and Critical Care, The University of Chicago, Chicago, Illinois, United States of America
- * E-mail:
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Lobo FA, Vacas S, Rossetti AO, Robba C, Taccone FS. Does electroencephalographic burst suppression still play a role in the perioperative setting? Best Pract Res Clin Anaesthesiol 2020; 35:159-169. [PMID: 34030801 DOI: 10.1016/j.bpa.2020.10.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 10/21/2020] [Accepted: 10/27/2020] [Indexed: 12/18/2022]
Abstract
With the widespread use of electroencephalogram [EEG] monitoring during surgery or in the Intensive Care Unit [ICU], clinicians can sometimes face the pattern of burst suppression [BS]. The BS pattern corresponds to the continuous quasi-periodic alternation between high-voltage slow waves [the bursts] and periods of low voltage or even isoelectricity of the EEG signal [the suppression] and is extremely rare outside ICU and the operative room. BS can be secondary to increased anesthetic depth or a marker of cerebral damage, as a therapeutic endpoint [i.e., refractory status epilepticus or refractory intracranial hypertension]. In this review, we report the neurophysiological features of BS to better define its role during intraoperative and critical care settings.
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Affiliation(s)
- Francisco Almeida Lobo
- Anesthesiology Department, Centro Hospitalar de Trás-os-Montes e Alto Douro, Avenida da Noruega, Lordelo, 5000-508, Vila Real, Portugal.
| | - Susana Vacas
- Department of Anesthesiology and Perioperative Medicine, University of California Los Angeles, Reagan UCLA Medical Center, 757 Westwood Plaza #3325, Los Angeles, CA, 90095, USA.
| | - Andrea O Rossetti
- Department of Neurology, Lausanne University Hospital and University of Lausanne, CH-1011, Lausanne, Switzerland.
| | - Chiara Robba
- Azienda Ospedaliera Universitaria San Martino di Genova, Largo Rosanna Benzi,15, 16100, Genova, Italy.
| | - Fabio Silvio Taccone
- Hopital Érasme, Université Libre de Bruxelles, Department of Intensive Care Medicine, Route de Lennik, 808 1070, Brussels, Belgium.
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25
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State entropy and burst suppression ratio can show contradictory information. Eur J Anaesthesiol 2020; 37:1084-1092. [DOI: 10.1097/eja.0000000000001312] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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26
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Hristovska I, Verdonk F, Comte JC, Tsai ES, Desestret V, Honnorat J, Chrétien F, Pascual O. Ketamine/xylazine and barbiturates modulate microglial morphology and motility differently in a mouse model. PLoS One 2020; 15:e0236594. [PMID: 32760073 PMCID: PMC7410236 DOI: 10.1371/journal.pone.0236594] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 07/08/2020] [Indexed: 12/30/2022] Open
Abstract
Microglia, the resident immune cells of the brain, are highly ramified and motile and their morphology is strongly linked to their function. Microglia constantly monitor the brain parenchyma and are crucial for maintaining brain homeostasis and fine-tuning neuronal networks. Besides affecting neurons, anesthetics may have wide-ranging effects mediated by non-neuronal cells and in particular microglia. We thus examined the effect of two commonly used anesthetic agents, ketamine/xylazine and barbiturates, on microglial motility and morphology. A combination of two-photon in vivo imaging and electroencephalography (EEG) recordings in unanesthetized and anesthetized mice as well as automated analysis of ex vivo sections were used to assess morphology and dynamics of microglia. We found that administration of ketamine/xylazine and pentobarbital anesthesia resulted in quite distinct EEG profiles. Both anesthetics reduced microglial motility, but only ketamine/xylazine administration led to reduction of microglial complexity in vivo. The change of cellular dynamics in vivo was associated with a region-dependent reduction of several features of microglial cells ex vivo, such as the complexity index and the ramification length, whereas thiopental altered the size of the cytoplasm. Our results show that anesthetics have considerable effects on neuronal activity and microglial morphodynamics and that barbiturates may be a preferred anesthetic agent for the study of microglial morphology. These findings will undoubtedly raise compelling questions about the functional relevance of anesthetics on microglial cells in neuronal physiology and anesthesia-induced neurotoxicity.
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Affiliation(s)
- Ines Hristovska
- Equipe Synaptopathies et Autoanticorps (SynatAc), Institut NeuroMyoGène, INSERM U1217/UMR CNRS 5310, Lyon, France
- Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
| | - Franck Verdonk
- Unité Neuropathologie Expérimentale, Département Infection et Epidémiologie, Institut Pasteur, Paris, France
- Department d’anesthésiologie et de Soins Intensifs, Hôpital Saint Antoine, Assistance Publique-Hôpitaux de Paris, Paris, France
- Sorbonne Université, Paris, France
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Jean-Christophe Comte
- Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
- Equipe Processus d’oubli et Dynamique Corticale, Centre de Recherche en Neuroscience de Lyon (CRNL), INSERM U1028, CNRS UMR5292, Lyon, France
| | - Eileen S. Tsai
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Virginie Desestret
- Equipe Synaptopathies et Autoanticorps (SynatAc), Institut NeuroMyoGène, INSERM U1217/UMR CNRS 5310, Lyon, France
- Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
- Centre maladies rares sur les syndromes neurologiques paranéoplasiques, Hospices Civils de Lyon, Lyon, France
| | - Jérôme Honnorat
- Equipe Synaptopathies et Autoanticorps (SynatAc), Institut NeuroMyoGène, INSERM U1217/UMR CNRS 5310, Lyon, France
- Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
- Centre maladies rares sur les syndromes neurologiques paranéoplasiques, Hospices Civils de Lyon, Lyon, France
| | - Fabrice Chrétien
- Unité Neuropathologie Expérimentale, Département Infection et Epidémiologie, Institut Pasteur, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
- Laboratoire Hospitalo-Universitaire de Neuropathologie, Centre Hospitalier Sainte Anne, Paris, France
- * E-mail: (FC); (OP)
| | - Olivier Pascual
- Equipe Synaptopathies et Autoanticorps (SynatAc), Institut NeuroMyoGène, INSERM U1217/UMR CNRS 5310, Lyon, France
- Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
- * E-mail: (FC); (OP)
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27
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Reimann HM, Niendorf T. The (Un)Conscious Mouse as a Model for Human Brain Functions: Key Principles of Anesthesia and Their Impact on Translational Neuroimaging. Front Syst Neurosci 2020; 14:8. [PMID: 32508601 PMCID: PMC7248373 DOI: 10.3389/fnsys.2020.00008] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 01/27/2020] [Indexed: 12/11/2022] Open
Abstract
In recent years, technical and procedural advances have brought functional magnetic resonance imaging (fMRI) to the field of murine neuroscience. Due to its unique capacity to measure functional activity non-invasively, across the entire brain, fMRI allows for the direct comparison of large-scale murine and human brain functions. This opens an avenue for bidirectional translational strategies to address fundamental questions ranging from neurological disorders to the nature of consciousness. The key challenges of murine fMRI are: (1) to generate and maintain functional brain states that approximate those of calm and relaxed human volunteers, while (2) preserving neurovascular coupling and physiological baseline conditions. Low-dose anesthetic protocols are commonly applied in murine functional brain studies to prevent stress and facilitate a calm and relaxed condition among animals. Yet, current mono-anesthesia has been shown to impair neural transmission and hemodynamic integrity. By linking the current state of murine electrophysiology, Ca2+ imaging and fMRI of anesthetic effects to findings from human studies, this systematic review proposes general principles to design, apply and monitor anesthetic protocols in a more sophisticated way. The further development of balanced multimodal anesthesia, combining two or more drugs with complementary modes of action helps to shape and maintain specific brain states and relevant aspects of murine physiology. Functional connectivity and its dynamic repertoire as assessed by fMRI can be used to make inferences about cortical states and provide additional information about whole-brain functional dynamics. Based on this, a simple and comprehensive functional neurosignature pattern can be determined for use in defining brain states and anesthetic depth in rest and in response to stimuli. Such a signature can be evaluated and shared between labs to indicate the brain state of a mouse during experiments, an important step toward translating findings across species.
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Affiliation(s)
- Henning M. Reimann
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrück Center for Molecular Medicine, Helmholtz Association of German Research Centers (HZ), Berlin, Germany
| | - Thoralf Niendorf
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrück Center for Molecular Medicine, Helmholtz Association of German Research Centers (HZ), Berlin, Germany
- Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine, Berlin, Germany
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28
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Gwilt M, Bauer M, Bast T. Frequency- and state-dependent effects of hippocampal neural disinhibition on hippocampal local field potential oscillations in anesthetized rats. Hippocampus 2020; 30:1021-1043. [PMID: 32396678 DOI: 10.1002/hipo.23212] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 03/09/2020] [Accepted: 04/09/2020] [Indexed: 11/11/2022]
Abstract
Reduced inhibitory GABA function, so-called neural disinhibition, has been implicated in cognitive disorders, including schizophrenia and age-related cognitive decline. We previously showed in rats that hippocampal disinhibition by local microinfusion of the GABA-A receptor antagonist picrotoxin disrupted memory and attention and enhanced hippocampal multi-unit burst firing recorded around the infusion site under isoflurane anesthesia. Here, we analyzed the hippocampal local field potential (LFP) recorded alongside the multi-unit data. We predicted frequency-specific LFP changes, based on previous studies implicating GABA in hippocampal oscillations, with the weight of evidence suggesting that disinhibition would facilitate theta and disrupt gamma oscillations. Using a new semi-automated method based on the kurtosis of the LFP peak-amplitude distribution as well as on amplitude envelope thresholding, we separated three distinct hippocampal LFP states under isoflurane anesthesia: "burst" and "suppression" states-high-amplitude LFP spike bursts and the interspersed low-amplitudeperiods-and a medium-amplitude "continuous" state. The burst state showed greater overall power than suppression and continuous states and higher relative delta/theta power, but lower relative beta/gamma power. The burst state also showed reduced functional connectivity across the hippocampal recording area, especially around theta and beta frequencies. Overall neuronal firing was higher in the burst than the other two states, whereas the proportion of burst firing was higher in burst and continuous states than the suppression state. Disinhibition caused state- and frequency-dependent LFP changes, tending to increase power at lower frequencies (<20 Hz), but to decrease power and connectivity at higher frequencies (>20 Hz) in burst and suppression states. The disinhibition-induced enhancement of multi-unit bursting was also state-dependent, tending to be more pronounced in burst and suppression states than the continuous state. Overall, we characterized three distinct hippocampal LFP states in isoflurane-anesthetized rats. Disinhibition changed hippocampal LFP oscillations in a state- and frequency-dependent way. Moreover, the disinhibition-induced enhancement of multi-unit bursting was also LFP state-dependent.
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Affiliation(s)
- Miriam Gwilt
- School of Psychology and Neuroscience@Nottingham, University of Nottingham, Nottingham, UK
| | - Markus Bauer
- School of Psychology and Neuroscience@Nottingham, University of Nottingham, Nottingham, UK
| | - Tobias Bast
- School of Psychology and Neuroscience@Nottingham, University of Nottingham, Nottingham, UK
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29
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Joksimovic SL, Joksimovic SM, Manzella FM, Asnake B, Orestes P, Raol YH, Krishnan K, Covey DF, Jevtovic-Todorovic V, Todorovic SM. Novel neuroactive steroid with hypnotic and T-type calcium channel blocking properties exerts effective analgesia in a rodent model of post-surgical pain. Br J Pharmacol 2020; 177:1735-1753. [PMID: 31732978 DOI: 10.1111/bph.14930] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 10/30/2019] [Accepted: 11/02/2019] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Neuroactive steroid (3β,5β,17β)-3-hydroxyandrostane-17-carbonitrile (3β-OH) is a novel hypnotic and voltage-dependent blocker of T-type calcium channels. Here, we examine its potential analgesic effects and adjuvant anaesthetic properties using a post-surgical pain model in rodents. EXPERIMENTAL APPROACH Analgesic properties of 3β-OH were investigated in thermal and mechanical nociceptive tests in sham or surgically incised rats and mice, with drug injected either systemically (intraperitoneal) or locally via intrathecal or intraplantar routes. Hypnotic properties of 3β-OH and its use as an adjuvant anaesthetic in combination with isoflurane were investigated using behavioural experiments and in vivo EEG recordings in adolescent rats. KEY RESULTS A combination of 1% isoflurane with 3β-OH (60 mg·kg-1 , i.p.) induced suppression of cortical EEG and stronger thermal and mechanical anti-hyperalgesia during 3 days post-surgery, when compared to isoflurane alone and isoflurane with morphine. 3β-OH exerted prominent enantioselective thermal and mechanical antinociception in healthy rats and reduced T-channel-dependent excitability of primary sensory neurons. Intrathecal injection of 3β-OH alleviated mechanical hyperalgesia, while repeated intraplantar application alleviated both thermal and mechanical hyperalgesia in the rats after incision. Using mouse genetics, we found that CaV 3.2 T-calcium channels are important for anti-hyperalgesic effect of 3β-OH and are contributing to its hypnotic effect. CONCLUSION AND IMPLICATIONS Our study identifies 3β-OH as a novel analgesic for surgical procedures. 3β-OH can be used to reduce T-channel-dependent excitability of peripheral sensory neurons as an adjuvant for induction and maintenance of general anaesthesia while improving analgesia and lowering the amount of volatile anaesthetic needed for surgery.
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Affiliation(s)
- Sonja Lj Joksimovic
- Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, Co, USA.,Pharmacology Graduate Program, Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia
| | - Srdjan M Joksimovic
- Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, Co, USA
| | - Francesca M Manzella
- Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, Co, USA.,Neuroscience Graduate Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Betelehem Asnake
- Department of Anesthesiology and Pain Medicine, University of California, Davis, CA, USA
| | - Peihan Orestes
- Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, Co, USA
| | - Yogendra H Raol
- Department of Pediatrics, Division of Neurology, Translational Epilepsy Research Program, Washington University School of Medicine, St. Louis, MO, USA
| | - Kathiresan Krishnan
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Douglas F Covey
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA.,Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
| | - Vesna Jevtovic-Todorovic
- Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, Co, USA
| | - Slobodan M Todorovic
- Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, Co, USA.,Neuroscience Graduate Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
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30
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Agrawal U, Berde CB, Cornelissen L. Electroencephalographic features of discontinuous activity in anesthetized infants and children. PLoS One 2019; 14:e0223324. [PMID: 31581269 PMCID: PMC6776336 DOI: 10.1371/journal.pone.0223324] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 09/18/2019] [Indexed: 11/25/2022] Open
Abstract
Background Discontinuous electroencephalographic activity in children is thought to reflect brain inactivation. Discontinuity has been observed in states of pathology, where it is predictive of adverse neurological outcome, as well as under general anesthesia. Though in preterm-infants discontinuity reflects normal brain development, less is known regarding its role in term children, particularly in the setting of general anesthesia. Here, we conduct a post-hoc exploratory analysis to investigate the spectral features of discontinuous activity in children under general anesthesia. Methods We previously recorded electroencephalography in children less than forty months of age under general anesthesia (n = 65). We characterized the relationship between age, anesthetic depth, and discontinuous activity, and used multitaper spectral methods to compare the power spectra of subjects with (n = 35) and without (n = 30) discontinuous activity. In the subjects with discontinuous activity, we examined the amplitude and power spectra associated with the discontinuities and analyzed how these variables varied with age. Results Cumulative time of discontinuity was associated with increased anesthetic depth and younger age. In particular, age-matched children with discontinuity received higher doses of propofol during induction as compared with children without discontinuity. In the tens of seconds preceding the onset of discontinuous activity, there was a decrease in high-frequency power in children four months and older that could be visually observed with spectrograms. During discontinuous activity, there were distinctive patterns of amplitude, spectral edge, and power in canonical frequency bands that varied with age. Notably, there was a decline in spectral edge in the seconds immediately following each discontinuity. Conclusion Discontinuous activity in children reflects a state of a younger or more deeply anesthetized brain, and characteristic features of discontinuous activity evolve with age and may reflect neurodevelopment.
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Affiliation(s)
- Uday Agrawal
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Charles B. Berde
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Laura Cornelissen
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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31
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Montandon G, Horner RL. Electrocortical changes associating sedation and respiratory depression by the opioid analgesic fentanyl. Sci Rep 2019; 9:14122. [PMID: 31575947 PMCID: PMC6773755 DOI: 10.1038/s41598-019-50613-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 09/12/2019] [Indexed: 01/05/2023] Open
Abstract
Opioid drugs are the mainstay of pain management but present the side-effect of respiratory depression that can be lethal with overdose. In addition to their respiratory effect, opioids also induce a profound sedative state and produce electrocortical features characteristic of a state of reduced brain arousal, similar to anaesthesia or sleep. In such states, respiratory activity depends more on the integrity of the brainstem respiratory network than it does during wakefulness. Accordingly, we propose that sedation by fentanyl induces specific electrocortical changes consistent with reduced brain arousal, and that the magnitude of respiratory depression is associated with distinct electrocortical changes. To these aims, we determined the effects of systemic injections of fentanyl (dosage 100 µg ·kg) versus control on electrocortical and respiratory activities of freely-behaving rats. We found that fentanyl induced electrocortical changes that differed from those observed in sleep or wakefulness. Fentanyl increased δ (1-3 Hz) frequency power (P < 0.001), but reduced α (7.5-13.5 Hz) and β2 (20-30 Hz) powers (P = 0.012 and P < 0.001, respectively), when compared to wakefulness. Interestingly, respiratory rate depression by fentanyl was significantly correlated with increased θ power (R = 0.61, P < 0.001), therefore showing a clear association between electrocortical activity and the magnitude of respiratory rate depression. Overall, we provide new evidence linking specific electrocortical changes to the severity of respiratory depression by opioids, which highlights the importance of considering the cortical and subcortical effects of opioids in addition to their impacts on breathing when evaluating opioid-induced respiratory depression.
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Affiliation(s)
- Gaspard Montandon
- Department of Medicine, Faculty of Medicine, University of Toronto, Toronto, Canada.
- Keenan Research Centre for Biomedical Sciences, Unity Health Toronto - St. Michael's Hospital, Toronto, Canada.
| | - Richard L Horner
- Department of Medicine, Faculty of Medicine, University of Toronto, Toronto, Canada
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Canada
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32
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Yang C, Zhang L, Hao H, Ran M, Li J, Dong H. Serotonergic neurons in the dorsal raphe nucleus mediate the arousal-promoting effect of orexin during isoflurane anesthesia in male rats. Neuropeptides 2019; 75:25-33. [PMID: 30935682 DOI: 10.1016/j.npep.2019.03.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 03/18/2019] [Accepted: 03/19/2019] [Indexed: 11/23/2022]
Abstract
Previous studies have demonstrated that the activation of orexinergic neurons facilitates the recovery of animals from general anesthesia. Moreover, serotonergic neurons that receive projections from orexin neurons have also been shown to participate in sleep-wakefulness regulation. In the present study, we aimed to explore whether orexinergic neurons facilitate emergence from isoflurane anesthesia in rats by activating serotonergic neurons. Orexin A (30 or 100 pmol), orexin B (30 or 100 pmol), and their respective antagonists SB-334867 and TCS-OX2-29 (5 or 20 μg) were microinjected into the dorsal raphe nucleus (DRN) of rats, and their effects on induction and emergence times were analyzed. Electroencephalogram (EEG) changes were also recorded and analyzed to illuminate the effect of orexin injection into the DRN on cortical excitability under isoflurane anesthesia. Activation of serotonergic neurons was detected via immunohistochemical analysis of c-Fos expression following orexin administration. Our results indicated that injection of neither orexins nor orexin antagonists into the rat DRN exerted an impact on induction time, whereas orexin-A injection (100 pmol) enhanced arousal when compared with the saline group. In contrast, administration of orexin receptor type 1 antagonist SB-334867 (20 μg) prolonged emergence time from isoflurane anesthesia. Microinjection of orexin-A induced an arousal pattern on EEG, and decreased the burst suppression ratio under isoflurane anesthesia. Isoflurane anesthesia inhibited the activity of serotonergic neurons, as shown by decrease in the number of c-Fos-immunoreactive serotonergic neurons when compared with the sham group. This inhibitory effect was partially reversed by administration of orexin-A. Taken together, our findings suggest that orexinergic signals facilitate emergence from isoflurane anesthesia, at least partially, by reversing the effects of isoflurane on serotonergic neurons of the DRN.
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Affiliation(s)
- Cen Yang
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, Shaanxi, China; Department of Anesthesiology, Shenzhen University General Hospital, Shenzhen University, Shenzhen, Guangdong Province 518055, China
| | - Lina Zhang
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of stomatology, Xi'an Jiaotong University, Xi'an 710032, Shaanxi, China
| | - Haizhi Hao
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, Shaanxi, China
| | - Mingzi Ran
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, Shaanxi, China
| | - Jiannan Li
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, Shaanxi, China
| | - Hailong Dong
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, Shaanxi, China.
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Palanca BJA, Wildes TS, Ju YS, Ching S, Avidan MS. Electroencephalography and delirium in the postoperative period. Br J Anaesth 2018; 119:294-307. [PMID: 28854540 DOI: 10.1093/bja/aew475] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Delirium commonly manifests in the postoperative period as a clinical syndrome resulting from acute brain dysfunction or encephalopathy. Delirium is characterized by acute and often fluctuating changes in attention and cognition. Emergence delirium typically presents and resolves within minutes to hours after termination of general anaesthesia. Postoperative delirium hours to days after an invasive procedure can herald poor outcomes. Easily recognized when patients are hyperactive or agitated, delirium often evades diagnosis as it most frequently presents with hypoactivity and somnolence. EEG offers objective measurements to complement clinical assessment of this complex fluctuating disorder. Although EEG features of delirium in the postoperative period remain incompletely characterized, a shift of EEG power into low frequencies is a typical finding shared among encephalopathies that manifest with delirium. In aggregate, existing data suggest that serial or continuous EEG in the postoperative period facilitates monitoring of delirium development and severity and assists in detecting epileptic aetiologies. Future studies are needed to clarify the precise EEG features that can reliably predict or diagnose delirium in the postoperative period, and to provide mechanistic insights into this pathologically diverse neurological disorder.
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Affiliation(s)
| | | | | | - S Ching
- Department of Electrical and Systems Engineering.,Department of Biomedical Engineering
| | - M S Avidan
- Department of Anesthesiology.,Department of Surgery, Division of Cardiothoracic Surgery, Washington University School of Medicine in St Louis, St Louis, MO, USA
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34
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Fleischmann A, Pilge S, Kiel T, Kratzer S, Schneider G, Kreuzer M. Substance-Specific Differences in Human Electroencephalographic Burst Suppression Patterns. Front Hum Neurosci 2018; 12:368. [PMID: 30297992 PMCID: PMC6160564 DOI: 10.3389/fnhum.2018.00368] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 08/28/2018] [Indexed: 12/17/2022] Open
Abstract
Different anesthetic agents induce burst suppression in the electroencephalogram (EEG) at very deep levels of general anesthesia. EEG burst suppression has been identified to be a risk factor for postoperative delirium (POD). EEG based automated detection algorithms are used to detect burst suppression patterns during general anesthesia and a burst suppression ratio (BSR) is calculated. Unfortunately, applied algorithms do not give information as precisely as suggested, often resulting in an underestimation of the patients’ burst suppression level. Additional knowledge of substance-specific burst suppression patterns could be of great importance to improve the ability of EEG based monitors to detect burst suppression. In a re-analysis of EEG recordings obtained from a previous study, we analyzed EEG data of 45 patients undergoing elective surgery under general anesthesia. The patients were anesthetized with sevoflurane, isoflurane or propofol (n = 15, for each group). After skin incision, the used agent was titrated to a level when burst suppression occurred. In a visual analysis of the EEG, blinded to the used anesthetic agent, we included the first distinct burst in our analysis. To avoid bias through changing EEG dynamics throughout the burst, we only focused on the first 2 s of the burst. These episodes were analyzed using the power spectral density (PSD) and normalized PSD, the absolute burst amplitude and absolute burst slope, as well as permutation entropy (PeEn). Our results show significant substance-specific differences in the architecture of the burst. Volatile-induced bursts showed higher burst amplitudes and higher burst power. Propofol-induced bursts had significantly higher relative power in the EEG alpha-range. Further, isoflurane-induced bursts had the steepest burst slopes. We can present the first systematic comparison of substance-specific burst characteristics during anesthesia. Previous observations, mostly derived from animal studies, pointing out the substance-specific differences in bursting behavior, concur with our findings. Our findings of substance-specific EEG characteristics can provide information to help improve automated burst suppression detection in monitoring devices. More specific detection of burst suppression may be helpful to reduce excessive EEG effects of anesthesia and therefore the incidence of adverse outcomes such as POD.
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Affiliation(s)
- Antonia Fleischmann
- Department of Anesthesiology and Intensive Care, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Stefanie Pilge
- Department of Anesthesiology and Intensive Care, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Tobias Kiel
- Department of Anesthesiology and Intensive Care, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Stephan Kratzer
- Department of Anesthesiology and Intensive Care, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Gerhard Schneider
- Department of Anesthesiology and Intensive Care, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Matthias Kreuzer
- Department of Anesthesiology and Intensive Care, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
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Walsh EC, Lee JM, Terzakis K, Zhou DW, Burns S, Buie TM, Firth PG, Shank ES, Houle TT, Brown EN, Purdon PL. Age-Dependent Changes in the Propofol-Induced Electroencephalogram in Children With Autism Spectrum Disorder. Front Syst Neurosci 2018; 12:23. [PMID: 29988455 PMCID: PMC6024139 DOI: 10.3389/fnsys.2018.00023] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 05/04/2018] [Indexed: 12/14/2022] Open
Abstract
Patients with autism spectrum disorder (ASD) often require sedation or general anesthesia. ASD is thought to arise from deficits in GABAergic signaling leading to abnormal neurodevelopment. We sought to investigate differences in how ASD patients respond to the GABAergic drug propofol by comparing the propofol-induced electroencephalogram (EEG) of ASD and neurotypical (NT) patients. This investigation was a prospective observational study. Continuous 4-channel frontal EEG was recorded during routine anesthetic care of patients undergoing endoscopic procedures between July 1, 2014 and May 1, 2016. Study patients were defined as those with previously diagnosed ASD by DSM-V criteria, aged 2-30 years old. NT patients were defined as those lacking neurological or psychiatric abnormalities, aged 2-30 years old. The primary outcome was changes in propofol-induced alpha (8-13 Hz) and slow (0.1-1 Hz) oscillation power by age. A post hoc analysis was performed to characterize incidence of burst suppression during propofol anesthesia. The primary risk factor of interest was a prior diagnosis of ASD. Outcomes were compared between ASD and NT patients using Bayesian methods. Compared to NT patients, slow oscillation power was initially higher in ASD patients (17.05 vs. 14.20 dB at 2.33 years), but progressively declined with age (11.56 vs. 13.95 dB at 22.5 years). Frontal alpha power was initially lower in ASD patients (17.65 vs. 18.86 dB at 5.42 years) and continued to decline with age (6.37 vs. 11.89 dB at 22.5 years). The incidence of burst suppression was significantly higher in ASD vs. NT patients (23.0% vs. 12.2%, p < 0.01) despite reduced total propofol dosing in ASD patients. Ultimately, we found that ASD patients respond differently to propofol compared to NT patients. A similar pattern of decreased alpha power and increased sensitivity to burst suppression develops in older NT adults; one interpretation of our data could be that ASD patients undergo a form of accelerated neuronal aging in adolescence. Our results suggest that investigations of the propofol-induced EEG in ASD patients may enable insights into the underlying differences in neural circuitry of ASD and yield safer practices for managing patients with ASD.
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Affiliation(s)
- Elisa C Walsh
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, United States.,Harvard Medical School, Boston, MA, United States.,Harvard Medical School/Massachusetts Institute of Technology, Division of Health Sciences and Technology, Cambridge, MA, United States
| | - Johanna M Lee
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, United States.,Harvard Medical School, Boston, MA, United States.,Harvard Medical School/Massachusetts Institute of Technology, Division of Health Sciences and Technology, Cambridge, MA, United States
| | - Kristina Terzakis
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, United States.,College of Nursing, Villanova University, Villanova, PA, United States
| | - David W Zhou
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, United States.,Lurie Center for Autism, Mass General Hospital for Children, Boston, MA, United States
| | - Sara Burns
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, United States
| | - Timothy M Buie
- Lurie Center for Autism, Mass General Hospital for Children, Boston, MA, United States.,Department of Gastroenterology, Mass General Hospital for Children, Boston, MA, United States
| | - Paul G Firth
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, United States
| | - Erik S Shank
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, United States
| | - Timothy T Houle
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, United States
| | - Emery N Brown
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, United States.,Harvard Medical School, Boston, MA, United States.,Harvard Medical School/Massachusetts Institute of Technology, Division of Health Sciences and Technology, Cambridge, MA, United States.,Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA, United States.,Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Patrick L Purdon
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, United States.,Harvard Medical School, Boston, MA, United States
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Kratzer S, Mattusch C, Garcia PS, Schmid S, Kochs E, Rammes G, Schneider G, Kreuzer M, Haseneder R. Propofol and Sevoflurane Differentially Modulate Cortical Depolarization following Electric Stimulation of the Ventrobasal Thalamus. Front Comput Neurosci 2017; 11:109. [PMID: 29321737 PMCID: PMC5732174 DOI: 10.3389/fncom.2017.00109] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 11/13/2017] [Indexed: 01/14/2023] Open
Abstract
The neuronal mechanisms how anesthetics lead to loss of consciousness are unclear. Thalamocortical interactions are crucially involved in conscious perception; hence the thalamocortical network might be a promising target for anesthetic modulation of neuronal information pertaining to arousal and waking behavior. General anesthetics affect the neurophysiology of the thalamus and the cortex but the exact mechanisms of how anesthetics interfere with processing thalamocortical information remain to be elucidated. Here we investigated the effect of the anesthetic agents sevoflurane and propofol on thalamocortical network activity in vitro. We used voltage-sensitive dye imaging techniques to analyze the cortical depolarization in response to stimulation of the thalamic ventrobasal nucleus in brain slices from mice. Exposure to sevoflurane globally decreased cortical depolarization in a dose-dependent manner. Sevoflurane reduced the intensity and extent of cortical depolarization and delayed thalamocortical signal propagation. In contrast, propofol neither affected area nor amplitude of cortical depolarization. However, propofol exposure resulted in regional changes in spatial distribution of maximum fluorescence intensity in deep regions of the cortex. In summary, our experiments revealed substance-specific effects on the thalamocortical network. Functional changes of the neuronal network are known to be pivotally involved in the anesthetic-induced loss of consciousness. Our findings provide further evidence that the mechanisms of anesthetic-mediated loss of consciousness are drug- and pathway-specific.
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Affiliation(s)
- Stephan Kratzer
- Department of Anesthesiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Corinna Mattusch
- Department of Anesthesiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Paul S Garcia
- Department of Anesthesiology, Emory University, Atlanta, GA, United States
- Research Service, Atlanta VA Medical Center, Atlanta, GA, United States
| | - Sebastian Schmid
- Department of Anesthesiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Eberhard Kochs
- Department of Anesthesiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Gerhard Rammes
- Department of Anesthesiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Gerhard Schneider
- Department of Anesthesiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Matthias Kreuzer
- Department of Anesthesiology, Emory University, Atlanta, GA, United States
- Research Service, Atlanta VA Medical Center, Atlanta, GA, United States
| | - Rainer Haseneder
- Department of Anesthesiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
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Hudetz AG, Vizuete JA, Pillay S, Mashour GA. Repertoire of mesoscopic cortical activity is not reduced during anesthesia. Neuroscience 2016; 339:402-417. [PMID: 27751957 PMCID: PMC5118138 DOI: 10.1016/j.neuroscience.2016.10.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 10/04/2016] [Accepted: 10/05/2016] [Indexed: 10/20/2022]
Abstract
Consciousness has been linked to the repertoire of brain states at various spatiotemporal scales. Anesthesia is thought to modify consciousness by altering information integration in cortical and thalamocortical circuits. At a mesoscopic scale, neuronal populations in the cortex form synchronized ensembles whose characteristics are presumably state-dependent but this has not been rigorously tested. In this study, spontaneous neuronal activity was recorded with 64-contact microelectrode arrays in primary visual cortex of chronically instrumented, unrestrained rats under stepwise decreasing levels of desflurane anesthesia (8%, 6%, 4%, and 2% inhaled concentrations) and wakefulness (0% concentration). Negative phases of the local field potentials formed compact, spatially contiguous activity patterns (CAPs) that were not due to chance. The number of CAPs was 120% higher in wakefulness and deep anesthesia associated with burst-suppression than at intermediate levels of consciousness. The frequency distribution of CAP sizes followed a power-law with slope -1.5 in relatively deep anesthesia (8-6%) but deviated from that at the lighter levels. Temporal variance and entropy of CAP sizes were lowest in wakefulness (76% and 24% lower at 0% than at 8% desflurane, respectively) but changed little during recovery of consciousness. CAPs categorized by K-means clustering were conserved at all anesthesia levels and wakefulness, although their proportion changed in a state-dependent manner. These observations yield new knowledge about the dynamic landscape of ongoing population activity in sensory cortex at graded levels of anesthesia. The repertoire of population activity and self-organized criticality at the mesoscopic scale do not appear to contribute to anesthetic suppression of consciousness, which may instead depend on large-scale effects, more subtle dynamic properties, or changes outside of primary sensory cortex.
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Affiliation(s)
- Anthony G Hudetz
- Department of Anesthesiology, Center for Consciousness Science, Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, United States.
| | - Jeannette A Vizuete
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Siveshigan Pillay
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI, United States
| | - George A Mashour
- Department of Anesthesiology, Center for Consciousness Science, Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, United States
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Williams AJ, Zhou C, Sun QQ. Enhanced Burst-Suppression and Disruption of Local Field Potential Synchrony in a Mouse Model of Focal Cortical Dysplasia Exhibiting Spike-Wave Seizures. Front Neural Circuits 2016; 10:93. [PMID: 27891080 PMCID: PMC5102891 DOI: 10.3389/fncir.2016.00093] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 10/31/2016] [Indexed: 11/28/2022] Open
Abstract
Focal cortical dysplasias (FCDs) are a common cause of brain seizures and are often associated with intractable epilepsy. Here we evaluated aberrant brain neurophysiology in an in vivo mouse model of FCD induced by neonatal freeze lesions (FLs) to the right cortical hemisphere (near S1). Linear multi-electrode arrays were used to record extracellular potentials from cortical and subcortical brain regions near the FL in anesthetized mice (5–13 months old) followed by 24 h cortical electroencephalogram (EEG) recordings. Results indicated that FL animals exhibit a high prevalence of spontaneous spike-wave discharges (SWDs), predominately during sleep (EEG), and an increase in the incidence of hyper-excitable burst/suppression activity under general anesthesia (extracellular recordings, 0.5%–3.0% isoflurane). Brief periods of burst activity in the local field potential (LFP) typically presented as an arrhythmic pattern of increased theta-alpha spectral peaks (4–12 Hz) on a background of low-amplitude delta activity (1–4 Hz), were associated with an increase in spontaneous spiking of cortical neurons, and were highly synchronized in control animals across recording sites in both cortical and subcortical layers (average cross-correlation values ranging from +0.73 to +1.0) with minimal phase shift between electrodes. However, in FL animals, cortical vs. subcortical burst activity was strongly out of phase with significantly lower cross-correlation values compared to controls (average values of −0.1 to +0.5, P < 0.05 between groups). In particular, a marked reduction in the level of synchronous burst activity was observed, the closer the recording electrodes were to the malformation (Pearson’s Correlation = 0.525, P < 0.05). In a subset of FL animals (3/9), burst activity also included a spike or spike-wave pattern similar to the SWDs observed in unanesthetized animals. In summary, neonatal FLs increased the hyperexcitable pattern of burst activity induced by anesthesia and disrupted field potential synchrony between cortical and subcortical brain regions near the site of the cortical malformation. Monitoring the altered electrophysiology of burst activity under general anesthesia with multi-dimensional micro-electrode arrays may serve to define distinct neurophysiological biomarkers of epileptogenesis in human brain and improve techniques for surgical resection of epileptogenic malformed brain tissue.
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Affiliation(s)
- Anthony J Williams
- Department of Zoology and Physiology, University of Wyoming Laramie, WY, USA
| | - Chen Zhou
- Department of Zoology and Physiology, University of Wyoming Laramie, WY, USA
| | - Qian-Quan Sun
- Department of Zoology and Physiology, University of Wyoming Laramie, WY, USA
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39
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Liu S, Ching S. Homeostatic dynamics, hysteresis and synchronization in a low-dimensional model of burst suppression. J Math Biol 2016; 74:1011-1035. [PMID: 27549764 DOI: 10.1007/s00285-016-1048-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 05/03/2016] [Indexed: 01/24/2023]
Abstract
Burst suppression, a pattern of the electroencephalogram characterized by quasi-periodic alternation of high-voltage activity (burst) and isoelectric silence (suppression), is typically associated with states of unconsciousness, such as in deep general anesthesia and certain etiologies of coma. Recent computational models for burst suppression have attributed the slow (up to tens of seconds) time-scale of burst termination and re-initiation to cycling in supportive physiological process, such as cerebral metabolism. That is, activity-dependent substrate ('energy') depletion during bursts, followed by substrate recovery during suppression. Such a model falls into the category of a fast-slow dynamical system, commonly used to describe neuronal bursting more generally. Here, following this basic paradigm, we develop a low dimensional mean field model for burst suppression that adds several new features and capabilities to previous models. Most notably, this new model includes explicit homeostatic interactions wherein the rates of substrate recovery are tied to neuronal activity in a supply demand loop, creating a physiologically consistent, reciprocal interaction between the neural and substrate processes. We develop formal analysis of the model dynamics, showing, in particular, the capability of the model to produce burst-like activity as a consequence of neuronal downregulation only, without any direct perturbation to the substrate dynamics. Further, we use a synchronization analysis to contrast different mechanisms for spatially local versus global bursting. The analysis performed generates characterizations that are consistent with experimental observations of spatiotemporal features such as burst onset, duration, and spatial organization and, moreover, generates predictions regarding the presence of bistability and hysteresis in the underlying system. Thus, the model provides new dynamical insight into the mechanisms of burst suppression and, moreover, a tractable platform for more detailed future characterizations.
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Affiliation(s)
- Sensen Liu
- Department of Electrical and Systems Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - ShiNung Ching
- Department of Electrical and Systems Engineering, Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO, 63130, USA.
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40
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Cascella M, Schiavone V, Muzio MR, Cuomo A. Consciousness fluctuation during general anesthesia: a theoretical approach to anesthesia awareness and memory modulation. Curr Med Res Opin 2016; 32:1351-9. [PMID: 27046232 DOI: 10.1080/03007995.2016.1174679] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
With anesthesia awareness as a model of study we debate the both fascinating and dangerous phenomenon called consciousness fluctuation that takes place during surgical anesthesia. In accordance with current scientific knowledge this paradox is the consequence of our limits in both precise knowledge of anesthesia mechanisms and our inability to accurately assess the level of anesthesia with brain monitoring. We also focus on the relationships between memory and anesthesia, as well as the possibility of interfering with memory during general anesthesia.
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Affiliation(s)
- Marco Cascella
- a Division of Anesthesia, Department of Anesthesia, Endoscopy and Cardiology , Istituto Nazionale Tumori "Fondazione G. Pascale" - IRCCS , Naples , Italy
| | - Vincenzo Schiavone
- b Division of Anesthesia and Intensive Care , Hospital "Pineta Grande" , Castel Volturno , Italy
| | - Maria Rosaria Muzio
- c Division of Infantile Neuropsychiatry , UOMI - Maternal and Infant Health , Torre del Greco , Naples , Italy
| | - Arturo Cuomo
- a Division of Anesthesia, Department of Anesthesia, Endoscopy and Cardiology , Istituto Nazionale Tumori "Fondazione G. Pascale" - IRCCS , Naples , Italy
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41
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Papadelis C, Ashkezari SFS, Doshi C, Thome-Souza S, Pearl PL, Grant PE, Tasker RC, Loddenkemper T. Real-time multi-channel monitoring of burst-suppression using neural network technology during pediatric status epilepticus treatment. Clin Neurophysiol 2016; 127:2820-2831. [PMID: 27417058 DOI: 10.1016/j.clinph.2016.05.358] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 05/12/2016] [Accepted: 05/27/2016] [Indexed: 12/19/2022]
Abstract
OBJECTIVE To develop a real-time monitoring system that has the potential to guide the titration of anesthetic agents in the treatment of pediatric status epilepticus (SE). METHODS We analyzed stored multichannel electroencephalographic (EEG) data collected from 12 pediatric patients with generalized SE. EEG recordings were initially segmented in 500ms time-windows. Features characterizing the power, frequency, and entropy of the signal were extracted from each segment. The segments were annotated as bursts (B), suppressions (S), or artifacts (A) by two electroencephalographers. The EEG features together with the annotations were inputted in a three-layer feed forward neural network (NN). The sensitivity and specificity of NNs with different architectures and training algorithms to classify segments into B, S, or A were estimated. RESULTS The maximum sensitivity (95.96% for B, 89.25% for S, and 75% for A) and specificity (89.36 for B, 96.26% for S, and 99.8% for A) was observed for the NN with 10 nodes in the hidden layer. By using this NN, we designed a real-time system that estimates the burst-suppression index (BSI). CONCLUSIONS Our system provides a reliable real-time estimate of multichannel BSI requiring minimal memory and computation time. SIGNIFICANCE The system has the potential to assist intensive care unit attendants in the continuous EEG monitoring.
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Affiliation(s)
- Christos Papadelis
- Center for Fetal-Neonatal Neuroimaging and Developmental Science, Boston Children's Hospital, Harvard Medical School, 1 Autumn St, Boston, MA 02215, USA; Division of Newborn Medicine, Department of Medicine, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave, Boston, MA 02115, USA.
| | - Seyedeh Fatemeh Salimi Ashkezari
- Center for Fetal-Neonatal Neuroimaging and Developmental Science, Boston Children's Hospital, Harvard Medical School, 1 Autumn St, Boston, MA 02215, USA; Division of Newborn Medicine, Department of Medicine, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave, Boston, MA 02115, USA
| | - Chiran Doshi
- Center for Fetal-Neonatal Neuroimaging and Developmental Science, Boston Children's Hospital, Harvard Medical School, 1 Autumn St, Boston, MA 02215, USA; Division of Newborn Medicine, Department of Medicine, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave, Boston, MA 02115, USA
| | - Sigride Thome-Souza
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave, Boston, MA 02115, USA
| | - Phillip L Pearl
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave, Boston, MA 02115, USA
| | - P Ellen Grant
- Center for Fetal-Neonatal Neuroimaging and Developmental Science, Boston Children's Hospital, Harvard Medical School, 1 Autumn St, Boston, MA 02215, USA; Division of Newborn Medicine, Department of Medicine, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave, Boston, MA 02115, USA; Department of Radiology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave, Boston, MA 02115, USA
| | - Robert C Tasker
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave, Boston, MA 02115, USA; Department of Anesthesia, Perioperative and Pain Medicine, Division of Critical Care Medicine, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave, Boston, MA 02115, USA
| | - Tobias Loddenkemper
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave, Boston, MA 02115, USA
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42
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Cascella M. Mechanisms underlying brain monitoring during anesthesia: limitations, possible improvements, and perspectives. Korean J Anesthesiol 2016; 69:113-20. [PMID: 27066200 PMCID: PMC4823404 DOI: 10.4097/kjae.2016.69.2.113] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 12/13/2015] [Accepted: 12/31/2015] [Indexed: 12/18/2022] Open
Abstract
Currently, anesthesiologists use clinical parameters to directly measure the depth of anesthesia (DoA). This clinical standard of monitoring is often combined with brain monitoring for better assessment of the hypnotic component of anesthesia. Brain monitoring devices provide indices allowing for an immediate assessment of the impact of anesthetics on consciousness. However, questions remain regarding the mechanisms underpinning these indices of hypnosis. By briefly describing current knowledge of the brain's electrical activity during general anesthesia, as well as the operating principles of DoA monitors, the aim of this work is to simplify our understanding of the mathematical processes that allow for translation of complex patterns of brain electrical activity into dimensionless indices. This is a challenging task because mathematical concepts appear remote from clinical practice. Moreover, most DoA algorithms are proprietary algorithms and the difficulty of exploring the inner workings of mathematical models represents an obstacle to accurate simplification. The limitations of current DoA monitors — and the possibility for improvement — as well as perspectives on brain monitoring derived from recent research on corticocortical connectivity and communication are also discussed.
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Affiliation(s)
- Marco Cascella
- Department of Anesthesia, Endoscopy and Cardiology, National Cancer Institute 'G Pascale' Foundation, Naples, Italy
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43
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Gauvin DV, Zimmermann ZJ, Baird TJ. Preclinical assessment of abuse liability of biologics: In defense of current regulatory control policies. Regul Toxicol Pharmacol 2015; 73:43-54. [DOI: 10.1016/j.yrtph.2015.06.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 06/11/2015] [Accepted: 06/12/2015] [Indexed: 01/16/2023]
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Chemali JJ, Kenny JD, Olutola O, Taylor NE, Kimchi EY, Purdon PL, Brown EN, Solt K. Ageing delays emergence from general anaesthesia in rats by increasing anaesthetic sensitivity in the brain. Br J Anaesth 2015; 115 Suppl 1:i58-i65. [PMID: 26174302 DOI: 10.1093/bja/aev112] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Little is known about ageing-related changes in the brain that affect emergence from general anaesthesia. We used young adult and aged Fischer 344 rats to test the hypothesis that ageing delays emergence from general anaesthesia by increasing anaesthetic sensitivity in the brain. METHODS Time to emergence was determined for isoflurane (1.5 vol% for 45 min) and propofol (8 mg kg(-1) i.v.). The dose of isoflurane required to maintain loss of righting (LOR) was established in young adult and aged rats. The efficacy of methylphenidate to reverse LOR from general anaesthesia was tested. Separate young adult and aged rats with implanted electroencephalogram (EEG) electrodes were used to test whether ageing increases sensitivity to anaesthetic-induced burst suppression. RESULTS Mean time to emergence from isoflurane anaesthesia was 47 s [95% CI 33, 60; young adult) compared with 243 s (95% CI 185, 308; aged). For propofol, mean time to emergence was 13.1 min (95% CI 11.9, 14.0; young adult) compared with 23.1 min (95% CI 18.8, 27.9; aged). These differences were statistically significant. When methylphenidate was administered after propofol, the mean time to emergence decreased to 6.6 min (95% CI 5.9, 7.1; young adult) and 10.2 min (95% CI 7.9, 12.3; aged). These reductions were statistically significant. Methylphenidate restored righting in all rats during continuous isoflurane anaesthesia. Aged rats had lower EEG power and were more sensitive to anaesthetic-induced burst suppression. CONCLUSIONS Ageing delays emergence from general anaesthesia. This is due, at least in part, to increased anaesthetic sensitivity in the brain. Further studies are warranted to establish the underlying causes.
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Affiliation(s)
- J J Chemali
- Department of Anaesthesia, Critical Care, and Pain Medicine and
| | - J D Kenny
- Department of Anaesthesia, Critical Care, and Pain Medicine and
| | - O Olutola
- Department of Anaesthesia, Critical Care, and Pain Medicine and
| | - N E Taylor
- Department of Anaesthesia, Critical Care, and Pain Medicine and Department of Anaesthesia, Harvard Medical School and
| | - E Y Kimchi
- Department of Neurology, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA Department of Neurology, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
| | - P L Purdon
- Department of Anaesthesia, Critical Care, and Pain Medicine and Department of Anaesthesia, Harvard Medical School and
| | - E N Brown
- Department of Anaesthesia, Critical Care, and Pain Medicine and Department of Anaesthesia, Harvard Medical School and Department of Brain and Cognitive Sciences Institute for Medical Engineering and Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - K Solt
- Department of Anaesthesia, Critical Care, and Pain Medicine and Department of Anaesthesia, Harvard Medical School and
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45
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Isoflurane inhibits synaptic vesicle exocytosis through reduced Ca2+ influx, not Ca2+-exocytosis coupling. Proc Natl Acad Sci U S A 2015; 112:11959-64. [PMID: 26351670 DOI: 10.1073/pnas.1500525112] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Identifying presynaptic mechanisms of general anesthetics is critical to understanding their effects on synaptic transmission. We show that the volatile anesthetic isoflurane inhibits synaptic vesicle (SV) exocytosis at nerve terminals in dissociated rat hippocampal neurons through inhibition of presynaptic Ca(2+) influx without significantly altering the Ca(2+) sensitivity of SV exocytosis. A clinically relevant concentration of isoflurane (0.7 mM) inhibited changes in [Ca(2+)]i driven by single action potentials (APs) by 25 ± 3%, which in turn led to 62 ± 3% inhibition of single AP-triggered exocytosis at 4 mM extracellular Ca(2+) ([Ca(2+)]e). Lowering external Ca(2+) to match the isoflurane-induced reduction in Ca(2+) entry led to an equivalent reduction in exocytosis. These data thus indicate that anesthetic inhibition of neurotransmitter release from small SVs occurs primarily through reduced axon terminal Ca(2+) entry without significant direct effects on Ca(2+)-exocytosis coupling or on the SV fusion machinery. Isoflurane inhibition of exocytosis and Ca(2+) influx was greater in glutamatergic compared with GABAergic nerve terminals, consistent with selective inhibition of excitatory synaptic transmission. Such alteration in the balance of excitatory to inhibitory transmission could mediate reduced neuronal interactions and network-selective effects observed in the anesthetized central nervous system.
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46
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Hutt A, Hudetz AG. Editorial: General anesthesia: from theory to experiments. Front Syst Neurosci 2015; 9:105. [PMID: 26257614 PMCID: PMC4510427 DOI: 10.3389/fnsys.2015.00105] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 07/10/2015] [Indexed: 12/15/2022] Open
Affiliation(s)
- Axel Hutt
- Team Neurosys, INRIA Villers-les-Nancy, France ; Team Neurosys, Centre National de la Recherche Scientifique, LORIA, UMR No. 7503 Villers-les-Nancy, France ; Team Neurosys, University of Lorraine, LORIA, UMR No. 7503 Villers-les-Nancy, France
| | - Anthony G Hudetz
- Department of Anesthesiology, Medical College of Wisconsin Milwaukee, WI, USA
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