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Gao H, Wang J, Zhang R, Luo T. Recent advances in neural mechanism of general anesthesia induced unconsciousness: insights from optogenetics and chemogenetics. Front Pharmacol 2024; 15:1360864. [PMID: 38655183 PMCID: PMC11035785 DOI: 10.3389/fphar.2024.1360864] [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: 12/24/2023] [Accepted: 03/20/2024] [Indexed: 04/26/2024] Open
Abstract
For over 170 years, general anesthesia has played a crucial role in clinical practice, yet a comprehensive understanding of the neural mechanisms underlying the induction of unconsciousness by general anesthetics remains elusive. Ongoing research into these mechanisms primarily centers around the brain nuclei and neural circuits associated with sleep-wake. In this context, two sophisticated methodologies, optogenetics and chemogenetics, have emerged as vital tools for recording and modulating the activity of specific neuronal populations or circuits within distinct brain regions. Recent advancements have successfully employed these techniques to investigate the impact of general anesthesia on various brain nuclei and neural pathways. This paper provides an in-depth examination of the use of optogenetic and chemogenetic methodologies in studying the effects of general anesthesia on specific brain nuclei and pathways. Additionally, it discusses in depth the advantages and limitations of these two methodologies, as well as the issues that must be considered for scientific research applications. By shedding light on these facets, this paper serves as a valuable reference for furthering the accurate exploration of the neural mechanisms underlying general anesthesia. It aids researchers and clinicians in effectively evaluating the applicability of these techniques in advancing scientific research and clinical practice.
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Affiliation(s)
- Hui Gao
- School of Anesthesiology, Shandong Second Medical University, Weifang, China
- Department of Anesthesiology, Peking University Shenzhen Hospital, Shenzhen, China
| | - Jingyi Wang
- Department of Anesthesiology, Peking University Shenzhen Hospital, Shenzhen, China
| | - Rui Zhang
- School of Anesthesiology, Shandong Second Medical University, Weifang, China
| | - Tao Luo
- Department of Anesthesiology, Peking University Shenzhen Hospital, Shenzhen, China
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Xiao W, Li P, Kong F, Kong J, Pan A, Long L, Yan X, Xiao B, Gong J, Wan L. Unraveling the Neural Circuits: Techniques, Opportunities and Challenges in Epilepsy Research. Cell Mol Neurobiol 2024; 44:27. [PMID: 38443733 PMCID: PMC10914928 DOI: 10.1007/s10571-024-01458-5] [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: 12/25/2023] [Accepted: 01/24/2024] [Indexed: 03/07/2024]
Abstract
Epilepsy, a prevalent neurological disorder characterized by high morbidity, frequent recurrence, and potential drug resistance, profoundly affects millions of people globally. Understanding the microscopic mechanisms underlying seizures is crucial for effective epilepsy treatment, and a thorough understanding of the intricate neural circuits underlying epilepsy is vital for the development of targeted therapies and the enhancement of clinical outcomes. This review begins with an exploration of the historical evolution of techniques used in studying neural circuits related to epilepsy. It then provides an extensive overview of diverse techniques employed in this domain, discussing their fundamental principles, strengths, limitations, as well as their application. Additionally, the synthesis of multiple techniques to unveil the complexity of neural circuits is summarized. Finally, this review also presents targeted drug therapies associated with epileptic neural circuits. By providing a critical assessment of methodologies used in the study of epileptic neural circuits, this review seeks to enhance the understanding of these techniques, stimulate innovative approaches for unraveling epilepsy's complexities, and ultimately facilitate improved treatment and clinical translation for epilepsy.
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Affiliation(s)
- Wenjie Xiao
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, Hunan Province, China
| | - Peile Li
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, Hunan Province, China
| | - Fujiao Kong
- Department of Anesthesiology, Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Jingyi Kong
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, Hunan Province, China
| | - Aihua Pan
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, Hunan Province, China
| | - Lili Long
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Xiaoxin Yan
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, Hunan Province, China
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Jiaoe Gong
- Department of Neurology, Hunan Children's Hospital, Changsha, Hunan Province, China.
| | - Lily Wan
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, Hunan Province, China.
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Lyu J, Cai H, Chen Y, Chen G. Brain areas modulation in consciousness during sevoflurane anesthesia. Front Integr Neurosci 2022; 16:1031613. [PMID: 36619239 PMCID: PMC9811387 DOI: 10.3389/fnint.2022.1031613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 11/28/2022] [Indexed: 12/24/2022] Open
Abstract
Sevoflurane is presently one of the most used inhaled anesthetics worldwide. However, the mechanisms through which sevoflurane acts and the areas of the brain associated with changes in consciousness during anesthesia remain important and complex research questions. Sevoflurane is generally regarded as a volatile anesthetic that blindly targets neuronal (and sometimes astrocyte) GABAA receptors. This review focuses on the brain areas of sevoflurane action and their relation to changes in consciousness during anesthesia. We cover 20 years of history, from the bench to the bedside, and include perspectives on functional magnetic resonance, electroencephalogram, and pharmacological experiments. We review the interactions and neurotransmitters involved in brain circuits during sevoflurane anesthesia, improving the effectiveness and accuracy of sevoflurane's future application and shedding light on the mechanisms behind human consciousness.
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Heshmati M, Bruchas MR. Historical and Modern Evidence for the Role of Reward Circuitry in Emergence. Anesthesiology 2022; 136:997-1014. [PMID: 35362070 PMCID: PMC9467375 DOI: 10.1097/aln.0000000000004148] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Increasing evidence supports a role for brain reward circuitry in modulating arousal along with emergence from anesthesia. Emergence remains an important frontier for investigation, since no drug exists in clinical practice to initiate rapid and smooth emergence. This review discusses clinical and preclinical evidence indicating a role for two brain regions classically considered integral components of the mesolimbic brain reward circuitry, the ventral tegmental area and the nucleus accumbens, in emergence from propofol and volatile anesthesia. Then there is a description of modern systems neuroscience approaches to neural circuit investigations that will help span the large gap between preclinical and clinical investigation with the shared aim of developing therapies to promote rapid emergence without agitation or delirium. This article proposes that neuroscientists include models of whole-brain network activity in future studies to inform the translational value of preclinical investigations and foster productive dialogues with clinician anesthesiologists.
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Affiliation(s)
- Mitra Heshmati
- Center for the Neurobiology of Addiction, Pain, and Emotion, Department of Anesthesiology and Pain Medicine, and Department of Biological Structure, University of Washington, Seattle, Washington
| | - Michael R Bruchas
- Center for the Neurobiology of Addiction, Pain, and Emotion, Department of Anesthesiology and Pain Medicine, and Department of Pharmacology, University of Washington, Seattle, Washington
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Song Y, Chu R, Cao F, Wang Y, Liu Y, Cao J, Guo Y, Mi W, Tong L. Dopaminergic Neurons in the Ventral Tegmental-Prelimbic Pathway Promote the Emergence of Rats from Sevoflurane Anesthesia. Neurosci Bull 2022; 38:417-428. [PMID: 34954810 PMCID: PMC9068857 DOI: 10.1007/s12264-021-00809-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 10/12/2021] [Indexed: 10/19/2022] Open
Abstract
Dopaminergic neurons in the ventral tegmental area (VTA) play an important role in cognition, emergence from anesthesia, reward, and aversion, and their projection to the cortex is a crucial part of the "bottom-up" ascending activating system. The prelimbic cortex (PrL) is one of the important projection regions of the VTA. However, the roles of dopaminergic neurons in the VTA and the VTADA-PrL pathway under sevoflurane anesthesia in rats remain unclear. In this study, we found that intraperitoneal injection and local microinjection of a dopamine D1 receptor agonist (Chloro-APB) into the PrL had an emergence-promoting effect on sevoflurane anesthesia in rats, while injection of a dopamine D1 receptor antagonist (SCH23390) deepened anesthesia. The results of chemogenetics combined with microinjection and optogenetics showed that activating the VTADA-PrL pathway prolonged the induction time and shortened the emergence time of anesthesia. These results demonstrate that the dopaminergic system in the VTA has an emergence-promoting effect and that the bottom-up VTADA-PrL pathway facilitates emergence from sevoflurane anesthesia.
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Affiliation(s)
- Yanping Song
- Anesthesia and Operation Center, The First Medical Center of Chinese, PLA General Hospital, Beijing, 100853, China
- Chinese PLA Medical School, Beijing, 100853, China
| | - Ruitong Chu
- Department of Anesthesia, Second Affiliated Hospital of Naval Medical University, Shanghai, 200003, China
| | - Fuyang Cao
- Department of Anesthesia, The Sixth Medical Center of Chinese, PLA General Hospital, Beijing, 100048, China
| | - Yanfeng Wang
- Department of Anesthesia, Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Yanhong Liu
- Anesthesia and Operation Center, The First Medical Center of Chinese, PLA General Hospital, Beijing, 100853, China
| | - Jiangbei Cao
- Anesthesia and Operation Center, The First Medical Center of Chinese, PLA General Hospital, Beijing, 100853, China
| | - Yongxin Guo
- Anesthesia and Operation Center, The First Medical Center of Chinese, PLA General Hospital, Beijing, 100853, China.
| | - Weidong Mi
- Anesthesia and Operation Center, The First Medical Center of Chinese, PLA General Hospital, Beijing, 100853, China.
| | - Li Tong
- Anesthesia and Operation Center, The First Medical Center of Chinese, PLA General Hospital, Beijing, 100853, China.
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Vincent KF, Zhang ER, Kato R, Cho A, Moody OA, Solt K. Return of the Righting Reflex Does Not Portend Recovery of Cognitive Function in Anesthetized Rats. Front Syst Neurosci 2021; 15:762096. [PMID: 34867222 PMCID: PMC8637163 DOI: 10.3389/fnsys.2021.762096] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 10/28/2021] [Indexed: 11/18/2022] Open
Abstract
As the number of individuals undergoing general anesthesia rises globally, it becomes increasingly important to understand how consciousness and cognition are restored after anesthesia. In rodents, levels of consciousness are traditionally captured by physiological responses such as the return of righting reflex (RORR). However, tracking the recovery of cognitive function is comparatively difficult. Here we use an operant conditioning task, the 5-choice serial reaction time task (5-CSRTT), to measure sustained attention, working memory, and inhibitory control in male and female rats as they recover from the effects of several different clinical anesthetics. In the 5-CSRTT, rats learn to attend to a five-windowed touchscreen for the presentation of a stimulus. Rats are rewarded with food pellets for selecting the correct window within the time limit. During each session we tracked both the proportion of correct (accuracy) and missed (omissions) responses over time. Cognitive recovery trajectories were assessed after isoflurane (2% for 1 h), sevoflurane (3% for 20 min), propofol (10 mg/kg I.V. bolus), ketamine (50 mg/kg I.V. infusion over 10 min), and dexmedetomidine (20 and 35 μg/kg I.V. infusions over 10 min) for up to 3 h following RORR. Rats were classified as having recovered accuracy performance when four of their last five responses were correct, and as having recovered low omission performance when they missed one or fewer of their last five trials. Following isoflurane, sevoflurane, and propofol anesthesia, the majority (63-88%) of rats recovered both accuracy and low omission performance within an hour of RORR. Following ketamine, accuracy performance recovers within 2 h in most (63%) rats, but low omission performance recovers in only a minority (32%) of rats within 3 h. Finally, following either high or low doses of dexmedetomidine, few rats (25-32%) recover accuracy performance, and even fewer (0-13%) recover low omission performance within 3 h. Regardless of the anesthetic, RORR latency is not correlated with 5-CSRTT performance, which suggests that recovery of neurocognitive function cannot be inferred from changes in levels of consciousness. These results demonstrate how operant conditioning tasks can be used to assess real-time recovery of neurocognitive function following different anesthetic regimens.
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Affiliation(s)
- Kathleen F. Vincent
- Anesthesia, Critical Care, and Pain Medicine, Massachusetts’s General Hospital, Boston, MA, United States,Harvard Medical School, Boston, MA, United States
| | - Edlyn R. Zhang
- Anesthesia, Critical Care, and Pain Medicine, Massachusetts’s General Hospital, Boston, MA, United States
| | - Risako Kato
- Anesthesia, Critical Care, and Pain Medicine, Massachusetts’s General Hospital, Boston, MA, United States,Harvard Medical School, Boston, MA, United States
| | - Angel Cho
- Touro College of Osteopathic Medicine, New York, NY, United States
| | - Olivia A. Moody
- Anesthesia, Critical Care, and Pain Medicine, Massachusetts’s General Hospital, Boston, MA, United States,Harvard Medical School, Boston, MA, United States
| | - Ken Solt
- Anesthesia, Critical Care, and Pain Medicine, Massachusetts’s General Hospital, Boston, MA, United States,Harvard Medical School, Boston, MA, United States,*Correspondence: Ken Solt,
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Voss L, Sleigh JW. Anesthesia Mechanisms: A Patchwork Quilt rather than a Wet Blanket? Anesthesiology 2021; 135:568-569. [PMID: 34468700 DOI: 10.1097/aln.0000000000003879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Logan Voss
- From the Department of Anaesthesiology, Waikato Clinical Campus, Faculty of Medical and Health Sciences, University of Auckland, Hamilton, New Zealand
| | - Jamie W Sleigh
- From the Department of Anaesthesiology, Waikato Clinical Campus, Faculty of Medical and Health Sciences, University of Auckland, Hamilton, New Zealand
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Excitation of Putative Glutamatergic Neurons in the Rat Parabrachial Nucleus Region Reduces Delta Power during Dexmedetomidine but not Ketamine Anesthesia. Anesthesiology 2021; 135:633-648. [PMID: 34270686 DOI: 10.1097/aln.0000000000003883] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
BACKGROUND Parabrachial nucleus excitation reduces cortical delta oscillation (0.5 to 4 Hz) power and recovery time associated with anesthetics that enhance γ-aminobutyric acid type A receptor action. The effects of parabrachial nucleus excitation on anesthetics with other molecular targets, such as dexmedetomidine and ketamine, remain unknown. The hypothesis was that parabrachial nucleus excitation would cause arousal during dexmedetomidine and ketamine anesthesia. METHODS Designer Receptors Exclusively Activated by Designer Drugs were used to excite calcium/calmodulin-dependent protein kinase 2α-positive neurons in the parabrachial nucleus region of adult male rats without anesthesia (nine rats), with dexmedetomidine (low dose: 0.3 µg · kg-1 · min-1 for 45 min, eight rats; high dose: 4.5 µg · kg-1 · min-1 for 10 min, seven rats), or with ketamine (low dose: 2 mg · kg-1 · min-1 for 30 min, seven rats; high dose: 4 mg · kg-1 · min-1 for 15 min, eight rats). For control experiments (same rats and treatments), the Designer Receptors Exclusively Activated by Designer Drugs were not excited. The electroencephalogram and anesthesia recovery times were recorded and analyzed. RESULTS Parabrachial nucleus excitation reduced delta power in the prefrontal electroencephalogram with low-dose dexmedetomidine for the 150-min analyzed period, excepting two brief periods (peak median bootstrapped difference [clozapine-N-oxide - saline] during dexmedetomidine infusion = -6.06 [99% CI = -12.36 to -1.48] dB, P = 0.007). However, parabrachial nucleus excitation was less effective at reducing delta power with high-dose dexmedetomidine and low- and high-dose ketamine (peak median bootstrapped differences during high-dose [dexmedetomidine, ketamine] infusions = [-1.93, -0.87] dB, 99% CI = [-4.16 to -0.56, -1.62 to -0.18] dB, P = [0.006, 0.019]; low-dose ketamine had no statistically significant decreases during the infusion). Recovery time differences with parabrachial nucleus excitation were not statistically significant for dexmedetomidine (median difference for [low, high] dose = [1.63, 11.01] min, 95% CI = [-20.06 to 14.14, -20.84 to 23.67] min, P = [0.945, 0.297]) nor low-dose ketamine (median difference = 12.82 [95% CI: -3.20 to 39.58] min, P = 0.109) but were significantly longer for high-dose ketamine (median difference = 11.38 [95% CI: 1.81 to 24.67] min, P = 0.016). CONCLUSIONS These results suggest that the effectiveness of parabrachial nucleus excitation to change the neurophysiologic and behavioral effects of anesthesia depends on the anesthetic's molecular target. EDITOR’S PERSPECTIVE
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Liu Y, Chen B, Cai Y, Han Y, Xia Y, Li N, Fan B, Yuan T, Jiang J, Gao PO, Yu W, Jiao Y, Li W. Activation of anterior thalamic reticular nucleus GABAergic neurons promotes arousal from propofol anesthesia in mice. Acta Biochim Biophys Sin (Shanghai) 2021; 53:883-892. [PMID: 33929026 DOI: 10.1093/abbs/gmab056] [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] [Received: 02/22/2021] [Indexed: 11/14/2022] Open
Abstract
Propofol is widely used for the induction and maintenance of anesthesia, which causes a rapid loss of consciousness. However, the mechanisms underlying the hypnosis effect of propofol are still not fully understood. The thalamic reticular nucleus (TRN) is crucial for regulating wakefulness, sleep rhythm generation, and sleep stability, while the role of TRN in the process of propofol-induced anesthesia is still unknown. Here, we investigated the function of the anterior TRN in propofol general anesthesia. Our results demonstrated that the neural activity of anterior TRN is suppressed during propofol anesthesia, whereas it is robustly activated from anesthesia by recording the calcium signals using fiber photometry technology. The results showed that the activation of anterior TRN neurons by chemogenetic and optogenetic methods shortens the emergency time without changing the induction time. Conversely, chemogenetic or optogenetic inhibition of the TRN neurons leads to a delay in the recovery time. Our study showed that anterior TRN is crucial for behavioral arousal without affecting the induction time of propofol anesthesia.
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Affiliation(s)
- Yanjun Liu
- Department of Anesthesiology, Eye and ENT Hospital, Fudan University, Shanghai 200031, China
| | - Bing Chen
- Department of Anesthesiology, Eye and ENT Hospital, Fudan University, Shanghai 200031, China
| | - Yirong Cai
- Department of Anesthesiology, Eye and ENT Hospital, Fudan University, Shanghai 200031, China
| | - Yuan Han
- Department of Anesthesiology, Eye and ENT Hospital, Fudan University, Shanghai 200031, China
| | - Ying Xia
- Department of Anesthesiology, Eye and ENT Hospital, Fudan University, Shanghai 200031, China
| | - Nanqi Li
- Department of Anesthesiology, Eye and ENT Hospital, Fudan University, Shanghai 200031, China
| | - Bingqian Fan
- Department of Anesthesiology, Eye and ENT Hospital, Fudan University, Shanghai 200031, China
| | - Tianjie Yuan
- Department of Anesthesiology, Eye and ENT Hospital, Fudan University, Shanghai 200031, China
| | - Junli Jiang
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - P o Gao
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Weifeng Yu
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Yingfu Jiao
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Wenxian Li
- Department of Anesthesiology, Eye and ENT Hospital, Fudan University, Shanghai 200031, China
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Lydic R, Baghdoyan HA. Prefrontal Cortex Metabolome Is Modified by Opioids, Anesthesia, and Sleep. Physiology (Bethesda) 2021; 36:203-219. [PMID: 34159803 DOI: 10.1152/physiol.00043.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Obtundation of wakefulness caused by opioids and loss of wakefulness caused by anesthetics and sleep significantly alter concentrations of molecules comprising the prefrontal cortex (PFC) metabolome. Quantifying state-selective changes in the PFC metabolome is essential for advancing functional metabolomics. Diverse functions of the PFC suggest the PFC metabolome as a potential therapeutic entry point for countermeasures to state-selective autonomic dysfunction.
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Affiliation(s)
- Ralph Lydic
- Psychology, University of Tennessee, Knoxville, Tennessee.,Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - Helen A Baghdoyan
- Psychology, University of Tennessee, Knoxville, Tennessee.,Oak Ridge National Laboratory, Oak Ridge, Tennessee
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11
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Moody OA, Zhang ER, Vincent KF, Kato R, Melonakos ED, Nehs CJ, Solt K. The Neural Circuits Underlying General Anesthesia and Sleep. Anesth Analg 2021; 132:1254-1264. [PMID: 33857967 DOI: 10.1213/ane.0000000000005361] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
General anesthesia is characterized by loss of consciousness, amnesia, analgesia, and immobility. Important molecular targets of general anesthetics have been identified, but the neural circuits underlying the discrete end points of general anesthesia remain incompletely understood. General anesthesia and natural sleep share the common feature of reversible unconsciousness, and recent developments in neuroscience have enabled elegant studies that investigate the brain nuclei and neural circuits underlying this important end point. A common approach to measure cortical activity across the brain is electroencephalogram (EEG), which can reflect local neuronal activity as well as connectivity among brain regions. The EEG oscillations observed during general anesthesia depend greatly on the anesthetic agent as well as dosing, and only some resemble those observed during sleep. For example, the EEG oscillations during dexmedetomidine sedation are similar to those of stage 2 nonrapid eye movement (NREM) sleep, but high doses of propofol and ether anesthetics produce burst suppression, a pattern that is never observed during natural sleep. Sleep is primarily driven by withdrawal of subcortical excitation to the cortex, but anesthetics can directly act at both subcortical and cortical targets. While some anesthetics appear to activate specific sleep-active regions to induce unconsciousness, not all sleep-active regions play a significant role in anesthesia. Anesthetics also inhibit cortical neurons, and it is likely that each class of anesthetic drugs produces a distinct combination of subcortical and cortical effects that lead to unconsciousness. Conversely, arousal circuits that promote wakefulness are involved in anesthetic emergence and activating them can induce emergence and accelerate recovery of consciousness. Modern neuroscience techniques that enable the manipulation of specific neural circuits have led to new insights into the neural circuitry underlying general anesthesia and sleep. In the coming years, we will continue to better understand the mechanisms that generate these distinct states of reversible unconsciousness.
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Affiliation(s)
- Olivia A Moody
- From the Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts.,Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts
| | - Edlyn R Zhang
- From the Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Kathleen F Vincent
- From the Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts.,Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts
| | - Risako Kato
- From the Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts.,Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts
| | - Eric D Melonakos
- From the Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts.,Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Christa J Nehs
- From the Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts.,Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Ken Solt
- From the Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts.,Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts
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12
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Combined implanted central venous access and cortical recording electrode array in freely behaving mice. MethodsX 2021; 8:101466. [PMID: 35004192 PMCID: PMC8720795 DOI: 10.1016/j.mex.2021.101466] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 07/19/2021] [Indexed: 11/22/2022] Open
Abstract
Establishing a long-lasting, functioning venous access in a non-anesthetized mouse is very challenging at least. Since we needed a reliable venous access to titrate intravenous anesthetics, we refined and combined previously described methods. The tunneling of the catheter from the cranial to the pectoral wound, the fixation of the catheter in the external jugular vein with two sutures, and a tissue adhesive allowed us to combine this method with the implantation of intracranial recording electrodes. With this approach we neither have to restrain the animal causing excessive stress nor do we need an additional anesthetic, interfering with the effects of the intravenous anesthetic. This approach can help to establish a greater understanding of the concept of consciousness by identifying the neural circuits which mediate the effect of intravenous anesthetics. In addition - due to the flexible design of the recording electrode array - our approach can also be applied to investigate further neuroscientific hypotheses.Establishment of a reliable chronical venous access for the application in freely behaving mice. The jugular venous access can be combined with all kinds of neurobiological recording and application designs. The design of the venous access allows chronic combinations with telemetric and tether-bound systems.
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