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Bu X, Chen Y, Lv P, Fu X, Fu B. Glutamatergic neurons in paraventricular nucleus of the thalamus regulate the recovery from isoflurane anesthesia. BMC Anesthesiol 2022; 22:256. [PMID: 35953781 PMCID: PMC9367068 DOI: 10.1186/s12871-022-01799-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 08/05/2022] [Indexed: 11/30/2022] Open
Abstract
Objectives Previous studies have demonstrated that the paraventricular nucleus of the thalamus (PVT) is a key wakefulness-controlling nucleus in the thalamus. Therefore, PVT may also be involved in the process of general anesthesia. This study intends to explore the role of PVT in isoflurane anesthesia. Methods In the present study, we used the expression of c-Fos to observe the neuronal activity of PVT neurons under isoflurane anesthesia. We further recorded the effect of isoflurane anesthesia on the calcium signal of PVT glutamatergic neurons in real time with the help of calcium fiber photometry. We finally used chemogenetic technology to specifically regulate PVT glutamatergic neurons, and observed its effect on isoflurane anesthesia and cortical electroencephalography (EEG) in mice. Results We found that glutamatergic neurons of PVT exhibited high activity during wakefulness and low activity during isoflurane anesthesia. Activation of PVT glutamatergic neuronal caused an acceleration in emergence from isoflurane anesthesia accompanied with a decrease in EEG delta power (1–4 Hz). Whereas suppression of PVT glutamatergic neurons induced a delay recovery of isoflurane anesthesia, without affecting anesthesia induction. Conclusions Assuming a pharmacokinetic explanation for results can be excluded, these results demonstrate that the PVT is involved in regulating anesthesia emergence.
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Affiliation(s)
- Xiaoli Bu
- Department of Critical Care Medicine, Affiliated Hospital of Zunyi Medical University, Guizhou Province, 563003, Zunyi city, China.,Guizhou Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical University, Zunyi city, 563003, Guizhou Province, China
| | - Yiqiu Chen
- Department of Critical Care Medicine, Affiliated Hospital of Zunyi Medical University, Guizhou Province, 563003, Zunyi city, China.,Guizhou Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical University, Zunyi city, 563003, Guizhou Province, China
| | - Ping Lv
- Department of Critical Care Medicine, Affiliated Hospital of Zunyi Medical University, Guizhou Province, 563003, Zunyi city, China.,Guizhou Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical University, Zunyi city, 563003, Guizhou Province, China
| | - Xiaoyun Fu
- Department of Critical Care Medicine, Affiliated Hospital of Zunyi Medical University, Guizhou Province, 563003, Zunyi city, China.,Guizhou Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical University, Zunyi city, 563003, Guizhou Province, China
| | - Bao Fu
- Department of Critical Care Medicine, Affiliated Hospital of Zunyi Medical University, Guizhou Province, 563003, Zunyi city, China. .,Guizhou Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical University, Zunyi city, 563003, Guizhou Province, China.
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2
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Wang J, Gong Y, Tan H, Li W, Yan B, Cheng C, Wan J, Sun W, Yuan C, Yao LH. Cordycepin suppresses glutamatergic and GABAergic synaptic transmission through activation of A 1 adenosine receptor in rat hippocampal CA1 pyramidal neurons. Biomed Pharmacother 2021; 145:112446. [PMID: 34808556 DOI: 10.1016/j.biopha.2021.112446] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 11/09/2021] [Accepted: 11/16/2021] [Indexed: 12/21/2022] Open
Abstract
Cordycepin (known as 3-deoxyadenosine, CRD), a natural product from the valuable traditional Chinese medicine Cordyceps militaris, has been reported to improve cognitive function and modulate neuroprotective effects on the central nervous system (CNS). However, the modulating mechanisms of cordycepin on information processing in hippocampal CA1 pyramidal neurons are not fully understood. To clarify how cordycepin modulates synaptic responses of pyramidal neurons in rat hippocampal CA1 region, we conducted an electrophysiological experiment using whole-cell patch-clamp technique. The spontaneous and miniature excitatory postsynaptic currents (sEPSCs and mEPSCs, respectively) and the spontaneous and miniature inhibitory postsynaptic currents (sIPSCs and mIPSCs, respectively) recorded by this technique evaluated pure single or multi-synapse responses and enabled us to accurately quantify how cordycepin influenced the pre and postsynaptic aspects of synaptic transmission. The present results showed that cordycepin significantly decreased the frequency of both glutamatergic and GABAergic postsynaptic currents without affecting the amplitude, while these inhibitory effects were antagonized by the A1 adenosine receptor antagonist (DPCPX), but not the A2A (ZM 241385), A2B (MRS1754) and A3 (MRS1191) adenosine receptor antagonists. Taken together, our results suggested that cordycepin had a clear presynaptic effect on glutamatergic and GABAergic transmission, and provided novel evidence that cordycepin suppresses the synaptic transmission through the activation of A1AR.
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Affiliation(s)
- Jinxiu Wang
- School of Life Science, Jiangxi Science & Technology Normal University, Nanchang, Jiangxi 330013, PR China
| | - Yanchun Gong
- School of Life Science, Jiangxi Science & Technology Normal University, Nanchang, Jiangxi 330013, PR China; School of Sport Science, Jiangxi Science & Technology Normal University, Nanchang, Jiangxi 330013, PR China
| | - Haoyuan Tan
- Clinical School of Acupuncture and Rehabilitation, Guangzhou University of Traditional Chinese Medicine, GuangZhou 510720, PR China
| | - Wenxi Li
- School of Life Science, Jiangxi Science & Technology Normal University, Nanchang, Jiangxi 330013, PR China
| | - Baiyi Yan
- School of Life Science, Jiangxi Science & Technology Normal University, Nanchang, Jiangxi 330013, PR China
| | - Chunfang Cheng
- School of Sport Science, Jiangxi Science & Technology Normal University, Nanchang, Jiangxi 330013, PR China
| | - Juan Wan
- School of Sport Science, Jiangxi Science & Technology Normal University, Nanchang, Jiangxi 330013, PR China
| | - Wei Sun
- School of Life Science, Jiangxi Science & Technology Normal University, Nanchang, Jiangxi 330013, PR China
| | - Chunhua Yuan
- School of Life Science, Jiangxi Science & Technology Normal University, Nanchang, Jiangxi 330013, PR China; School of Sport Science, Jiangxi Science & Technology Normal University, Nanchang, Jiangxi 330013, PR China
| | - Li-Hua Yao
- School of Life Science, Jiangxi Science & Technology Normal University, Nanchang, Jiangxi 330013, PR China; School of Sport Science, Jiangxi Science & Technology Normal University, Nanchang, Jiangxi 330013, PR China.
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3
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Effect of ketamine on voltage-gated potassium channels in rat primary sensory cortex pyramidal neurons. Neuroreport 2021; 31:583-589. [PMID: 32301815 DOI: 10.1097/wnr.0000000000001439] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Ketamine is an intravenous anesthetic commonly used in clinical, which has sedative and analgesic effects. Potassium channels exert many physiological functions in excitable cells. Therefore, potassium channels may be one of the targets of ketamine. In this study, we used patch clamp to study the effects of ketamine on voltage-gated potassium channels in primary sensory cortex (S1) neurons. We recorded the outward potassium currents (IA) and delayed rectifier potassium currents (IK) separately. We found that ketamine both concentration-dependently inhibited IA currents and IK currents in S1 neurons. Ketamine (100 and 300 μM) induced a concentration-dependent hyperpolarizing shift in V1/2, without affecting the slope factor (κ) or inactivation of IA. Ketamine induced a concentration-dependent hyperpolarizing shift in V1/2 of IK, without affecting its κ. Ketamine (100 and 300 μM) did not alter the steady-state activation or its κ. Hence, ketamine inhibits IA and IK in a concentration-dependent manner in S1 pyramidal neurons. The inactivation of IA does not appear to be involved in the inhibitory effect of ketamine on IA. Ketamine inhibits IK mainly by speeding up the inactivation of IK in S1 pyramidal neurons.
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4
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Zhang L, Fan S, Zhang J, Fang K, Wang L, Cao Y, Chen L, Liu X, Gu E. Electroencephalographic dynamics of etomidate-induced loss of consciousness. BMC Anesthesiol 2021; 21:108. [PMID: 33832426 PMCID: PMC8028814 DOI: 10.1186/s12871-021-01308-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 02/25/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Highly structured electroencephalography (EEG) oscillations can occur in adults during etomidate-induced general anesthesia, but the link between these two phenomena is poorly understood. Therefore, in the present study, we investigated the electroencephalogram dynamics of etomidate-induced loss of consciousness (LOC) in order to understand the neurological mechanism of etomidate-induced LOC. METHODS This study is a prospective observational study. Etomidate-induced anesthesia was performed on eligible patients undergoing elective surgery. We analyzed EEG data from 20 patients who received etomidate for the induction of general anesthesia. We used power spectra and coherence methods to process and analyze the EEG data. Our study was based on 4-channel EEG recordings. RESULTS Compared with the baseline (awake period), etomidate induced an increase in power in delta, theta, alpha and beta waves during LOC. Compared with the awake period, the delta-wave (1-4 Hz), alpha-wave(8-13 Hz), and theta-wave(4-8 Hz) coherence increased significantly during LOC, while the slow-wave (< 1 Hz) coherence decreased. However, the delta wave (1.0-4.0 Hz) during etomidate-induced LOC was more coherent than during the awake period (1.86-3.17 Hz, two-group test for coherence, p < 0.001). CONCLUSIONS The neural circuit mechanism of etomidate-induced LOC is closely related to the induction of oscillation in delta, theta, alpha and beta waves and the enhancement of delta-wave coherence. TRIAL REGISTRATION ChiCTR1800017110.
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Affiliation(s)
- Lei Zhang
- Department of Anesthesiology, The First Affiliated Hospital of Anhui Medical University, No. 218 Jixi road, Anhui province, 230022, Hefei, China.,Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China
| | - Shunqin Fan
- The First Medical College of Anhui Medical University, 230032, Hefei, China.,Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China
| | - Jiawei Zhang
- The First Medical College of Anhui Medical University, 230032, Hefei, China.,Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China
| | - Kun Fang
- The First Medical College of Anhui Medical University, 230032, Hefei, China.,Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China
| | - Lei Wang
- Department of Anesthesiology, The First Affiliated Hospital of Anhui Medical University, No. 218 Jixi road, Anhui province, 230022, Hefei, China.,Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China
| | - Yuanyuan Cao
- Department of Anesthesiology, The First Affiliated Hospital of Anhui Medical University, No. 218 Jixi road, Anhui province, 230022, Hefei, China.,Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China
| | - Lijian Chen
- Department of Anesthesiology, The First Affiliated Hospital of Anhui Medical University, No. 218 Jixi road, Anhui province, 230022, Hefei, China.,Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China
| | - Xuesheng Liu
- Department of Anesthesiology, The First Affiliated Hospital of Anhui Medical University, No. 218 Jixi road, Anhui province, 230022, Hefei, China.,Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China
| | - Erwei Gu
- Department of Anesthesiology, The First Affiliated Hospital of Anhui Medical University, No. 218 Jixi road, Anhui province, 230022, Hefei, China. .,Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China.
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Effects of ketamine on voltage-gated sodium channels in the barrel cortex and the ventral posteromedial nucleus slices of rats. Neuroreport 2020; 30:1197-1204. [PMID: 31568204 PMCID: PMC6855387 DOI: 10.1097/wnr.0000000000001344] [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] [Indexed: 11/25/2022]
Abstract
Ketamine is commonly used as a dissociative anesthetic with unique actions in the central nervous system. Previous studies have found that the thalamocortical systems play an important role in general anesthetics induced unconsciousness. Whether the voltage-gated sodium channels in the thalamocortical systems are the target of ketamine remain unclear. The present study used a whole-cell patch-clamp technique to observe the effects of ketamine on voltage-gated Na channels in thalamocortical pyramidal neurons. We found that IC50 of ketamine on Na currents in the primary somatosensory barrel cortex pyramidal neurons and the thalamus ventral posteromedial nucleus pyramidal neurons was 686.72 ± 39.92 and 842.65 ± 87.28 μM, respectively. Ketamine accelerated the Na channels inactivation and slowed inactivation of Na channels after recovery but did not affect the activation. We demonstrated the detailed suppression process of neural voltage-gated Na channels by ketamine on thalamocortical slice. This may provide a new insight into the mechanical explanation for the ketamine anesthesia.
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Yang C, Li C, Sun J, Lu X. Role of estradiol in mediation of etomidate-caused seizure-like activity in neonatal rats. Int J Dev Neurosci 2019; 78:170-177. [PMID: 31202866 DOI: 10.1016/j.ijdevneu.2019.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 05/19/2019] [Accepted: 06/12/2019] [Indexed: 10/26/2022] Open
Abstract
BACKGROUND The goal of this study was to investigate the effect of estradiol in mediation of electroencephalogram (EEG) abnormality induced by etomidate in neonatal rats. METHODS Sprague-Dawley rats were anesthetized using intraperitoneal etomidate for 2 h on postnatal days (P) 4, 5, or 6 and recorded electroencephalogram in two ways. First, pups were recorded EEG two and a half hours under etomidate anesthesia, in subgroups, estradiol receptor antagonist ICI182780 and estradiol synthase inhibitor formestane were given subcutaneously in male rats 15 min prior to etomidate. Second, pups were anesthetized with etomidate for 2 h on P4,5 or 6 and then recovered from anesthesia, EEG were recorded for one hour in two postnatal periods of P9-P11 and P14-P16. Subgroup rats that received bumetanide, NKCC1 inhibitor, to test the NKCC1-GABAAR signaling effect on neonatal brain development, negative control groups and maternally separated for 2 h on P4, 5, or 6 were studied in 16 groups. Each group's n was = 8. RESULTS Male pups showed more severe seizure-like activities than female pups in P4-P6 under etomidate anesthesia. Pups pretreated with ICI182780 and formestane showed a less abnormalities of EEG in male rats. Etomidate caused seizure-like activity in P4-P6 could extend to P9-P11, but not seen in P14-P16, Pretreated with bumetanide only alleviated abnormalities in male pups other than female in P9-P11. CONCLUSIONS Estradiol involves in the NKCC1-GABAAR mediated seizure-like activity caused by etomidte in neonatal rats and these the abnormality lasts near two weeks.
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Affiliation(s)
- Chunyao Yang
- Department of Anesthesiology, Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou, China
| | - Changsheng Li
- Department of Anesthesiology, Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou, China
| | - Jing Sun
- Department of Psychiatry, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Xihua Lu
- Department of Anesthesiology, Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou, China
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7
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Zhang Y, Fu B, Liu C, Yu S, Luo T, Zhang L, Zhou W, Yu T. Activation of noradrenergic terminals in the reticular thalamus delays arousal from propofol anesthesia in mice. FASEB J 2019; 33:7252-7260. [DOI: 10.1096/fj.201802164rr] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Yu Zhang
- Department of AnesthesiologyAffiliated Hospital of Zunyi Medical UniversityGuizhouChina
- Guizhou Key Laboratory of Anesthesia and Organ ProtectionZunyi Medical UniversityGuizhouChina
| | - Bao Fu
- Department of Critical Care MedicineAffiliated Hospital of Zunyi Medical UniversityGuizhouChina
| | - Chengxi Liu
- Guizhou Key Laboratory of Brain ScienceZunyi Medical UniversityGuizhouChina
| | - Shouyang Yu
- Guizhou Key Laboratory of Brain ScienceZunyi Medical UniversityGuizhouChina
| | - Tianyuan Luo
- Guizhou Key Laboratory of Anesthesia and Organ ProtectionZunyi Medical UniversityGuizhouChina
| | - Lin Zhang
- Guizhou Key Laboratory of Anesthesia and Organ ProtectionZunyi Medical UniversityGuizhouChina
| | - Wenjing Zhou
- Guizhou Key Laboratory of Anesthesia and Organ ProtectionZunyi Medical UniversityGuizhouChina
| | - Tian Yu
- Department of AnesthesiologyAffiliated Hospital of Zunyi Medical UniversityGuizhouChina
- Guizhou Key Laboratory of Anesthesia and Organ ProtectionZunyi Medical UniversityGuizhouChina
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8
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Zhang YM, Yu DX, Yin BS, Li XR, Li LN, Li YN, Wang YX, Chen Y, Liu WH, Gao L. Xylazine Regulates the Release of Glycine and Aspartic Acid in Rat Brain. J Vet Res 2018; 62:121-128. [PMID: 29978137 PMCID: PMC5957471 DOI: 10.1515/jvetres-2018-0017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 02/14/2018] [Indexed: 11/15/2022] Open
Abstract
Introduction Xylazine, a type of α2-adrenoceptors, is a commonly used drug in veterinary medicine. Xylazine-induced changes in the content of amino acid neurotransmitters - glycine (Gly) and aspartic acid (Asp), in different brain regions and neurons were studied. Material and Methods Wistar rats were administered 50 mg/kg or 70 mg/kg of xylazine by intraperitoneal injection. In addition, in vitro experiments were conducted, in which neurons were treated with 15 μg/mL, 25 μg/mL, 35μg/mL, and 45 μg/mL of xylazine. Test methods were based on the enzyme-linked immunosorbent assays (ELISA). Results During anaesthesia, Asp levels in each brain area were significantly lower compared to the control group. Except for the cerebrum, levels of Gly in other brain areas were significantly increased during the anaesthesia period. In vitro, xylazine-related neuron secretion of Gly increased significantly compared to the control group at 60 min and 90 min. Moreover, xylazine caused a significant decrease in the levels of Asp secreted by neurons at 20 min, but gradually returned to the level of the control group. Conclusion The data showed that during anaesthesia the overall levels of Asp decreased and overall levels of Gly increased. In addition, the inhibitory effect of xylazine on Asp and the promotion of Gly were dose-dependent. Our data showed that different effects of xylazine on excitatory and inhibitory neurotransmitters provided a theoretical basis for the mechanism of xylazine activity in clinical anaesthesia.
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Affiliation(s)
- Yi-Ming Zhang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150000, China
| | - Dong-Xu Yu
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150000, China
| | - Bai-Shuang Yin
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150000, China
| | - Xin-Ran Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150000, China
| | - Li-Na Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150000, China
| | - Ya-Nan Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150000, China
| | - Yu-Xin Wang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150000, China
| | - Yu Chen
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150000, China
| | - Wen-Han Liu
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150000, China
| | - Li Gao
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150000, China
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Abstract
Abstract
Introduction
Xylazine, a type of α2-adrenoceptors, is a commonly used drug in veterinary medicine. Xylazine-induced changes in the content of amino acid neurotransmitters – glycine (Gly) and aspartic acid (Asp), in different brain regions and neurons were studied.
Material and Methods
Wistar rats were administered 50 mg/kg or 70 mg/kg of xylazine by intraperitoneal injection. In addition, in vitro experiments were conducted, in which neurons were treated with 15 μg/mL, 25 μg/mL, 35μg/mL, and 45 μg/mL of xylazine. Test methods were based on the enzyme-linked immunosorbent assays (ELISA).
Results
During anaesthesia, Asp levels in each brain area were significantly lower compared to the control group. Except for the cerebrum, levels of Gly in other brain areas were significantly increased during the anaesthesia period. In vitro, xylazine-related neuron secretion of Gly increased significantly compared to the control group at 60 min and 90 min. Moreover, xylazine caused a significant decrease in the levels of Asp secreted by neurons at 20 min, but gradually returned to the level of the control group.
Conclusion
The data showed that during anaesthesia the overall levels of Asp decreased and overall levels of Gly increased. In addition, the inhibitory effect of xylazine on Asp and the promotion of Gly were dose-dependent. Our data showed that different effects of xylazine on excitatory and inhibitory neurotransmitters provided a theoretical basis for the mechanism of xylazine activity in clinical anaesthesia.
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Feng HJ, Forman SA. Comparison of αβδ and αβγ GABA A receptors: Allosteric modulation and identification of subunit arrangement by site-selective general anesthetics. Pharmacol Res 2017; 133:289-300. [PMID: 29294355 DOI: 10.1016/j.phrs.2017.12.031] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 12/28/2017] [Accepted: 12/29/2017] [Indexed: 12/27/2022]
Abstract
GABAA receptors play a dominant role in mediating inhibition in the mature mammalian brain, and defects of GABAergic neurotransmission contribute to the pathogenesis of a variety of neurological and psychiatric disorders. Two types of GABAergic inhibition have been described: αβγ receptors mediate phasic inhibition in response to transient high-concentrations of synaptic GABA release, and αβδ receptors produce tonic inhibitory currents activated by low-concentration extrasynaptic GABA. Both αβδ and αβγ receptors are important targets for general anesthetics, which induce apparently different changes both in GABA-dependent receptor activation and in desensitization in currents mediated by αβγ vs. αβδ receptors. Many of these differences are explained by correcting for the high agonist efficacy of GABA at most αβγ receptors vs. much lower efficacy at αβδ receptors. The stoichiometry and subunit arrangement of recombinant αβγ receptors are well established as β-α-γ-β-α, while those of αβδ receptors remain controversial. Importantly, some potent general anesthetics selectively bind in transmembrane inter-subunit pockets of αβγ receptors: etomidate acts at β+/α- interfaces, and the barbiturate R-5-allyl-1-methyl-5-(m-trifluoromethyl-diazirynylphenyl) barbituric acid (R-mTFD-MPAB) acts at α+/β- and γ+/β- interfaces. Thus, these drugs are useful as structural probes in αβδ receptors formed from free subunits or concatenated subunit assemblies designed to constrain subunit arrangement. Although a definite conclusion cannot be drawn, studies using etomidate and R-mTFD-MPAB support the idea that recombinant α1β3δ receptors may share stoichiometry and subunit arrangement with α1β3γ2 receptors.
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Affiliation(s)
- Hua-Jun Feng
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, and Department of Anesthesia, Harvard Medical School, Boston, MA 02114, USA.
| | - Stuart A Forman
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, and Department of Anesthesia, Harvard Medical School, Boston, MA 02114, USA.
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Fu B, Liu C, Zhang Y, Fu X, Zhang L, Yu T. Ketamine attenuates the glutamatergic neurotransmission in the ventral posteromedial nucleus slices of rats. BMC Anesthesiol 2017; 17:111. [PMID: 28835217 PMCID: PMC5569565 DOI: 10.1186/s12871-017-0404-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 08/16/2017] [Indexed: 01/15/2023] Open
Abstract
Background Ketamine is a frequently used intravenous anesthetic, which can reversibly induce loss of consciousness (LOC). Previous studies have demonstrated that thalamocortical system is critical for information transmission and integration in the brain. The ventral posteromedial nucleus (VPM) is a critical component of thalamocortical system. Glutamate is an important excitatory neurotransmitter in the brain and may be involved in ketamine-induced LOC. Methods The study used whole-cell patch-clamp to observe the effect of ketamine (30 μM–1000 μM) on glutamatergic neurotransmission in VPM slices. Results Ketamine significantly decreased the amplitude of glutamatergic spontaneous excitatory postsynaptic currents (sEPSCs), but only higher concentration of ketamine (300 μM and 1000 μM) suppressed the frequency of sEPSCs. Ketamine (100 μM–1000 μM) also decreased the amplitude of glutamatergic miniature excitatory postsynaptic currents (mEPSCs), without altering the frequency. Conclusions In VPM neurons, ketamine attenuates the glutamatergic neurotransmission mainly through postsynaptic mechanism and action potential may be involved in the process. Electronic supplementary material The online version of this article (doi:10.1186/s12871-017-0404-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Bao Fu
- Department of Critical Care Medicine, Affiliated Hospital of Zunyi Medical College, Zunyi, Guizhou, China
| | - Chengxi Liu
- Guizhou Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical College, Dalian Road, Zunyi, Guizhou, 201, China
| | - Yajun Zhang
- Guizhou Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical College, Dalian Road, Zunyi, Guizhou, 201, China
| | - Xiaoyun Fu
- Department of Critical Care Medicine, Affiliated Hospital of Zunyi Medical College, Zunyi, Guizhou, China
| | - Lin Zhang
- Guizhou Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical College, Dalian Road, Zunyi, Guizhou, 201, China
| | - Tian Yu
- Guizhou Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical College, Dalian Road, Zunyi, Guizhou, 201, China.
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12
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Fu B, Yu T, Yuan J, Gong X, Zhang M. Noradrenergic transmission in the central medial thalamic nucleus modulates the electroencephalographic activity and emergence from propofol anesthesia in rats. J Neurochem 2017; 140:862-873. [DOI: 10.1111/jnc.13939] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 12/20/2016] [Accepted: 12/21/2016] [Indexed: 11/29/2022]
Affiliation(s)
- Bao Fu
- Department of Anesthesiology; Shanghai Children's Medical Center; Shanghai Jiaotong University School of Medicine; Shanghai China
| | - Tian Yu
- Guizhou Key Laboratory of Anesthesia and Organ Protection; Zunyi Medical University; Zunyi Guizhou China
| | - Jie Yuan
- Department of Anesthesiology; Shanghai Children's Medical Center; Shanghai Jiaotong University School of Medicine; Shanghai China
| | - Xingrui Gong
- Department of Anesthesiology; Shanghai Children's Medical Center; Shanghai Jiaotong University School of Medicine; Shanghai China
| | - Mazhong Zhang
- Department of Anesthesiology; Shanghai Children's Medical Center; Shanghai Jiaotong University School of Medicine; Shanghai China
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