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Mizuno S, Asada R, Yu Y, Hamamoto Y, Hasegawa D. Investigation of the effect and availability of ketamine on electroencephalography in cats with temporal lobe epilepsy. Front Vet Sci 2023; 10:1236275. [PMID: 37559886 PMCID: PMC10407800 DOI: 10.3389/fvets.2023.1236275] [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: 06/07/2023] [Accepted: 07/10/2023] [Indexed: 08/11/2023] Open
Abstract
In recent years, electroencephalography (EEG) in veterinary medicine has become important not only in the diagnosis of epilepsy, but also in determining the epileptogenic focus. In cats, sedation and immobilization, usually with medetomidine or dexmedetomidine, are necessary to place the electrodes and to obtain stable scalp EEG recordings. In this study, we hypothesized that, for cats with temporal lobe epilepsy (TLE), ketamine, a sedative/anesthetic and N-methyl-D-aspartate (NMDA) antagonist that activates the limbic system and is also used to treat refractory status epilepticus in dogs, would induce sufficient sedation and immobilization for EEG, as well as induce interictal epileptiform discharges (IEDs) that are more pronounced than those induced with medetomidine. We obtained EEG recordings from TLE cats and healthy cats administered either ketamine or medetomidine alone (study 1) or ketamine after medetomidine sedation (study 2). In study 1, the frequency of IEDs showed no statistically significant difference between ketamine and medetomidine in both TLE and healthy cats. Seizures were observed in 75% (9/12) cats of the TLE group with ketamine alone. When ketamine was administered after sedation with medetomidine (study 2), 3/18 cats in the TLE group developed generalized tonic-clonic seizure and 1/18 cats showed subclinical seizure activity. However, no seizures were observed in all healthy cats in both study 1 and study 2. Slow wave activity at 2-4 Hz was observed in many individuals after ketamine administration regardless studies and groups, and quantitative analysis in study 2 showed a trend toward increased delta band activities in both groups. While there was no significant difference in the count of IEDs between medetomidine and ketamine, ketamine caused seizures in cats with TLE similar to their habitual seizure type and with a higher seizure frequency. Our results suggest that ketamine may activate epileptiform discharges during EEG recordings. However, caution should be used for cats with TLE.
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Affiliation(s)
- Satoshi Mizuno
- Laboratory of Veterinary Clinical Neurology, Graduate School of Nippon Veterinary and Life Science University, Musashino, Japan
| | - Rikako Asada
- Laboratory of Veterinary Clinical Neurology, Graduate School of Nippon Veterinary and Life Science University, Musashino, Japan
| | - Yoshihiko Yu
- Laboratory of Veterinary Clinical Neurology, Graduate School of Nippon Veterinary and Life Science University, Musashino, Japan
| | - Yuji Hamamoto
- Laboratory of Veterinary Clinical Neurology, Graduate School of Nippon Veterinary and Life Science University, Musashino, Japan
- Veterinary Medical Teaching Hospital, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Daisuke Hasegawa
- Laboratory of Veterinary Clinical Neurology, Graduate School of Nippon Veterinary and Life Science University, Musashino, Japan
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2
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Alterations in CNS Functions and DNA Methylation in Rats after 24 h Exposure to Peat Smoke. TOXICS 2021; 9:toxics9120342. [PMID: 34941776 PMCID: PMC8709141 DOI: 10.3390/toxics9120342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/01/2021] [Accepted: 12/07/2021] [Indexed: 11/17/2022]
Abstract
The use of a developed experimental model of a natural fire made it possible to assess the consequences of 24 h exposure to peat combustion products in albino rats. Peat smoke exposure leads to behavioral disturbances in rats, characterized by an increase in locomotor activity and an increased level of anxiety. Indicators of brain bioelectrical activity of the exposed animals supported the state of anxiety and psychoemotional stress. Epigenetic changes in the blood cells of exposed animals were revealed under 24 h exposure to peat smoke, characterized by a decrease in the level of global DNA methylation.
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Combined Low Dose of Ketamine and Social Isolation: A Possible Model of Induced Chronic Schizophrenia-Like Symptoms in Male Albino Rats. Brain Sci 2021; 11:brainsci11070917. [PMID: 34356151 PMCID: PMC8303272 DOI: 10.3390/brainsci11070917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 07/05/2021] [Accepted: 07/08/2021] [Indexed: 11/16/2022] Open
Abstract
While animal models for schizophrenia, ranging from pharmacological models to lesions and genetic models, are available, they usually mimic only the positive symptoms of this disorder. Identifying a feasible model of chronic schizophrenia would be valuable for studying the possible underlying mechanism and to investigate emerging treatments. Our hypothesis starts from the observation that combining ketamine with isolation could result in long-lasting neuro-psychological deficits and schizophrenia-like features; thus, it could probably be used as the first model of chronic schizophrenia that emphasizes the characteristic of having a multifactorial etiology. By the means of this study, we investigated the effects of ketamine administration combined with isolation in inducing schizophrenia-like symptoms in male albino rats and the brain reactive oxygen species levels. Our results showed that the number of lines crossings in the open field test, the number of open arm entries in the elevated plus maze, and the spontaneous alternations percentage in the Y-maze were significantly lower in the ketamine + isolation group compared to both the control and ketamine + social housing group (p < 0.05). Furthermore, the ketamine + isolation intervention significantly increased the MDA levels and decreased the GPx levels both in the hippocampus and the cortex of the rats. In addition, our premise of creating a model capable of exhibiting both positive and negative symptoms of schizophrenia was also based on adding the aripiprazole treatment to a group of rats. Therefore, we compared the ketamine + social isolation group with the ketamine + social isolation + aripiprazole group in order to attempt to discover if the antipsychotic drug would significantly decrease the potential positive schizophrenia-like symptoms induced by social isolation and ketamine. Given that we obtained significant results, we cautiously presume that this might be an important step in developing our animal model capable of illustrating both positive and negative symptoms of schizophrenia. This study could be a first step towards the creation of a complex animal model capable of exhibiting the multifactorial origin and manifestation of schizophrenia.
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Kanda T, Gotoh M, Makino A, Furumoto K, Shimizu Y, Itoi T, Maeta N, Furukawa T. Effect of Different Doses of Atipamezole on Reversal of Medetomidine-Induced Tear-Flow Decrease in Rats. Vet Sci 2020; 7:vetsci7040197. [PMID: 33287407 PMCID: PMC7761856 DOI: 10.3390/vetsci7040197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 11/28/2020] [Accepted: 12/02/2020] [Indexed: 11/16/2022] Open
Abstract
It has been reported that α2-adrenoceptor agonists such as medetomidine decrease tear flow in many species, including rats. Few studies have investigated the involvement of α2-adrenoceptor in decreased tear flow; the issue has not been illustrated sufficiently. Therefore, we aimed to investigate the effect of different doses of atipamezole on the reversal of medetomidine-induced tear-flow decrease to reveal the specific involvement of α2-adrenoceptor. Treatment with 400, 800, or 1600 µg/kg atipamezole (or saline as the control) was intramuscularly administered to rats 15 min following intramuscular administration of 200 µg/kg medetomidine. After medetomidine administration, tear flow was measured using a phenol red thread test (PRTT). PRTT values decreased significantly after 200 µg/kg medetomidine administration. The PRTT values after 800 (optimal dose to reverse) and 1600 µg/kg atipamezole administration reached baseline, but never exceeded it significantly. Treatment with 400 µg/kg atipamezole also reversed the decrease in PRTT value but the PRTT remained lower than baseline. The optimal dose and the higher dose of atipamezole fully reversed the medetomidine-induced decrease in tear flow to the baseline level in rats, while the lower dose of atipamezole partially recovered tear flow.
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Affiliation(s)
- Teppei Kanda
- Faculty of Veterinary Medicine, Okayama University of Science, 1-3 Ikoino-oka, Imabari, Ehime 794-8555, Japan; (K.F.); (Y.S.); (T.I.); (N.M.)
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan; (M.G.); (A.M.); (T.F.)
- Correspondence:
| | - Manami Gotoh
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan; (M.G.); (A.M.); (T.F.)
| | - Ayumi Makino
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan; (M.G.); (A.M.); (T.F.)
| | - Kayo Furumoto
- Faculty of Veterinary Medicine, Okayama University of Science, 1-3 Ikoino-oka, Imabari, Ehime 794-8555, Japan; (K.F.); (Y.S.); (T.I.); (N.M.)
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan; (M.G.); (A.M.); (T.F.)
| | - Yuki Shimizu
- Faculty of Veterinary Medicine, Okayama University of Science, 1-3 Ikoino-oka, Imabari, Ehime 794-8555, Japan; (K.F.); (Y.S.); (T.I.); (N.M.)
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan; (M.G.); (A.M.); (T.F.)
| | - Takamasa Itoi
- Faculty of Veterinary Medicine, Okayama University of Science, 1-3 Ikoino-oka, Imabari, Ehime 794-8555, Japan; (K.F.); (Y.S.); (T.I.); (N.M.)
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan; (M.G.); (A.M.); (T.F.)
| | - Noritaka Maeta
- Faculty of Veterinary Medicine, Okayama University of Science, 1-3 Ikoino-oka, Imabari, Ehime 794-8555, Japan; (K.F.); (Y.S.); (T.I.); (N.M.)
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan; (M.G.); (A.M.); (T.F.)
| | - Toshinori Furukawa
- Department of Comparative Animal Science, College of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505, Japan; (M.G.); (A.M.); (T.F.)
- Department of Animal Pharmaceutical Science, School of Pharmaceutical Science, Kyushu University of Health and Welfare, 1714-1 Yoshino-cho, Nobeoka, Miyazaki 882-8508, Japan
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Morgan KS, Parsons D, Cmielewski P, McCarron A, Gradl R, Farrow N, Siu K, Takeuchi A, Suzuki Y, Uesugi K, Uesugi M, Yagi N, Hall C, Klein M, Maksimenko A, Stevenson A, Hausermann D, Dierolf M, Pfeiffer F, Donnelley M. Methods for dynamic synchrotron X-ray respiratory imaging in live animals. JOURNAL OF SYNCHROTRON RADIATION 2020; 27:164-175. [PMID: 31868749 PMCID: PMC6927518 DOI: 10.1107/s1600577519014863] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 11/04/2019] [Indexed: 05/20/2023]
Abstract
Small-animal physiology studies are typically complicated, but the level of complexity is greatly increased when performing live-animal X-ray imaging studies at synchrotron and compact light sources. This group has extensive experience in these types of studies at the SPring-8 and Australian synchrotrons, as well as the Munich Compact Light Source. These experimental settings produce unique challenges. Experiments are always performed in an isolated radiation enclosure not specifically designed for live-animal imaging. This requires equipment adapted to physiological monitoring and test-substance delivery, as well as shuttering to reduce the radiation dose. Experiment designs must also take into account the fixed location, size and orientation of the X-ray beam. This article describes the techniques developed to overcome the challenges involved in respiratory X-ray imaging of live animals at synchrotrons, now enabling increasingly sophisticated imaging protocols.
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Affiliation(s)
- Kaye Susannah Morgan
- School of Physics and Astronomy, Monash University, Wellington Road, Clayton, VIC 3800, Australia
- Institute for Advanced Study, Technische Universität München, Garching Germany
- Chair of Biomedical Physics and Munich School of BioEngineering, Technische Universität München, 85748 Garching, Germany
| | - David Parsons
- Robinson Research Institute, University of Adelaide, SA 5006, Australia
- Adelaide Medical School, University of Adelaide, SA 5000, Australia
- Respiratory and Sleep Medicine, Women’s and Children’s Hospital, 72 King William Road, North Adelaide, SA 5006, Australia
| | - Patricia Cmielewski
- Robinson Research Institute, University of Adelaide, SA 5006, Australia
- Adelaide Medical School, University of Adelaide, SA 5000, Australia
- Respiratory and Sleep Medicine, Women’s and Children’s Hospital, 72 King William Road, North Adelaide, SA 5006, Australia
| | - Alexandra McCarron
- Robinson Research Institute, University of Adelaide, SA 5006, Australia
- Adelaide Medical School, University of Adelaide, SA 5000, Australia
- Respiratory and Sleep Medicine, Women’s and Children’s Hospital, 72 King William Road, North Adelaide, SA 5006, Australia
| | - Regine Gradl
- Institute for Advanced Study, Technische Universität München, Garching Germany
- Chair of Biomedical Physics and Munich School of BioEngineering, Technische Universität München, 85748 Garching, Germany
| | - Nigel Farrow
- Robinson Research Institute, University of Adelaide, SA 5006, Australia
- Adelaide Medical School, University of Adelaide, SA 5000, Australia
- Respiratory and Sleep Medicine, Women’s and Children’s Hospital, 72 King William Road, North Adelaide, SA 5006, Australia
| | - Karen Siu
- School of Physics and Astronomy, Monash University, Wellington Road, Clayton, VIC 3800, Australia
| | - Akihisa Takeuchi
- SPring-8, Japan Synchrotron Radiation Institute, Kouto, Hyogo, Japan
| | - Yoshio Suzuki
- SPring-8, Japan Synchrotron Radiation Institute, Kouto, Hyogo, Japan
| | - Kentaro Uesugi
- SPring-8, Japan Synchrotron Radiation Institute, Kouto, Hyogo, Japan
| | - Masayuki Uesugi
- SPring-8, Japan Synchrotron Radiation Institute, Kouto, Hyogo, Japan
| | - Naoto Yagi
- SPring-8, Japan Synchrotron Radiation Institute, Kouto, Hyogo, Japan
| | - Chris Hall
- Imaging and Medical Beamline, The Australian Synchrotron – ANSTO, 800 Blackburn Road, Clayton, VIC 3168, Australia
| | - Mitzi Klein
- Imaging and Medical Beamline, The Australian Synchrotron – ANSTO, 800 Blackburn Road, Clayton, VIC 3168, Australia
| | - Anton Maksimenko
- Imaging and Medical Beamline, The Australian Synchrotron – ANSTO, 800 Blackburn Road, Clayton, VIC 3168, Australia
| | - Andrew Stevenson
- Imaging and Medical Beamline, The Australian Synchrotron – ANSTO, 800 Blackburn Road, Clayton, VIC 3168, Australia
| | - Daniel Hausermann
- Imaging and Medical Beamline, The Australian Synchrotron – ANSTO, 800 Blackburn Road, Clayton, VIC 3168, Australia
| | - Martin Dierolf
- Chair of Biomedical Physics and Munich School of BioEngineering, Technische Universität München, 85748 Garching, Germany
| | - Franz Pfeiffer
- Institute for Advanced Study, Technische Universität München, Garching Germany
- Chair of Biomedical Physics and Munich School of BioEngineering, Technische Universität München, 85748 Garching, Germany
| | - Martin Donnelley
- Robinson Research Institute, University of Adelaide, SA 5006, Australia
- Adelaide Medical School, University of Adelaide, SA 5000, Australia
- Respiratory and Sleep Medicine, Women’s and Children’s Hospital, 72 King William Road, North Adelaide, SA 5006, Australia
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6
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Esteves M, Almeida AM, Silva J, Silva Moreira P, Carvalho E, Pêgo JM, Almeida A, Sotiropoulos I, Sousa N, Leite-Almeida H. MORPhA Scale: Behavioral and electroencephalographic validation of a rodent anesthesia scale. J Neurosci Methods 2019; 324:108304. [DOI: 10.1016/j.jneumeth.2019.05.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 05/24/2019] [Accepted: 05/25/2019] [Indexed: 10/26/2022]
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7
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Synergistic efficacy of tramadol and meloxicam on alleviation of pain and selected immunological variables after sciatic nerve ligation in rats. Int J Vet Sci Med 2019. [DOI: 10.1016/j.ijvsm.2013.12.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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8
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Sha J, Zhang H, Zhao Y, Feng X, Hu X, Wang C, Song M, Fan H. Dexmedetomidine attenuates lipopolysaccharide-induced liver oxidative stress and cell apoptosis in rats by increasing GSK-3β/MKP-1/Nrf2 pathway activity via the α2 adrenergic receptor. Toxicol Appl Pharmacol 2019; 364:144-152. [DOI: 10.1016/j.taap.2018.12.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 12/19/2018] [Accepted: 12/24/2018] [Indexed: 12/28/2022]
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Richardson AG, Liu X, Weigand PK, Hudgins ED, Stein JM, Das SR, Proekt A, Kelz MB, Zhang M, Van der Spiegel J, Lucas TH. Hippocampal gamma-slow oscillation coupling in macaques during sedation and sleep. Hippocampus 2017; 27:1125-1139. [PMID: 28667703 PMCID: PMC6883770 DOI: 10.1002/hipo.22757] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 05/22/2017] [Accepted: 06/16/2017] [Indexed: 11/07/2022]
Abstract
Behavioral and neurophysiological evidence suggests that the slow (≤1 Hz) oscillation (SO) during sleep plays a role in consolidating hippocampal (HIPP)-dependent memories. The effects of the SO on HIPP activity have been studied in rodents and cats both during natural sleep and during anesthetic administration titrated to mimic sleep-like slow rhythms. In this study, we sought to document these effects in primates. First, HIPP field potentials were recorded during ketamine-dexmedetomidine sedation and during natural sleep in three rhesus macaques. Sedation produced regionally-specific slow and gamma (∼40 Hz) oscillations with strong coupling between the SO phase and gamma amplitude. These same features were seen in slow-wave sleep (SWS), but the coupling was weaker and the coupled gamma oscillation had a higher frequency (∼70 Hz) during SWS. Second, electrical stimuli were delivered to HIPP afferents in the parahippocampal gyrus (PHG) during sedation to assess the effects of sleep-like SO on excitability. Gamma bursts after the peak of SO cycles corresponded to periods of increased gain of monosynaptic connections between the PHG and HIPP. However, the two PHG-HIPP connectivity gains during sedation were both substantially lower than when the animal was awake. We conclude that the SO is correlated with rhythmic excitation and inhibition of the PHG-HIPP network, modulating connectivity and gamma generators intrinsic to this network. Ketamine-dexmedetomidine sedation produces a similar effect, but with a decreased contribution of the PHG to HIPP activity and gamma generation.
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Affiliation(s)
| | - Xilin Liu
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Pauline K. Weigand
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Eric D. Hudgins
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Joel M. Stein
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Sandhitsu R. Das
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - Alexander Proekt
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Max B. Kelz
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Milin Zhang
- Department of Electronic Engineering, Tsinghua University, Beijing, China
| | - Jan Van der Spiegel
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Timothy H. Lucas
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA
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10
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Hüske C, Sander SE, Hamann M, Kershaw O, Richter F, Richter A. Towards optimized anesthesia protocols for stereotactic surgery in rats: Analgesic, stress and general health effects of injectable anesthetics. A comparison of a recommended complete reversal anesthesia with traditional chloral hydrate monoanesthesia. Brain Res 2016; 1642:364-375. [DOI: 10.1016/j.brainres.2016.04.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 03/17/2016] [Accepted: 04/07/2016] [Indexed: 11/29/2022]
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11
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Eftaxiopoulou T, Barnett-Vanes A, Arora H, Macdonald W, Nguyen TTN, Itadani M, Sharrock AE, Britzman D, Proud WG, Bull AMJ, Rankin SM. Prolonged but not short-duration blast waves elicit acute inflammation in a rodent model of primary blast limb trauma. Injury 2016; 47:625-32. [PMID: 26838938 DOI: 10.1016/j.injury.2016.01.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 01/06/2016] [Accepted: 01/14/2016] [Indexed: 02/02/2023]
Abstract
BACKGROUND Blast injuries from conventional and improvised explosive devices account for 75% of injuries from current conflicts; over 70% of injuries involve the limbs. Variable duration and magnitude of blast wave loading occurs in real-life explosions and is hypothesised to cause different injuries. While a number of in vivo models report the inflammatory response to blast injuries, the extent of this response has not been investigated with respect to the duration of the primary blast wave. The relevance is that explosions in open air are of short duration compared to those in confined spaces. METHODS Hindlimbs of adult Sprauge-Dawley rats were subjected to focal isolated primary blast waves of varying overpressure (1.8-3.65kPa) and duration (3.0-11.5ms), utilising a shock tube and purpose-built experimental rig. Rats were monitored during and after the blast. At 6 and 24h after exposure, blood, lungs, liver and muscle tissues were collected and prepared for histology and flow cytometry. RESULTS At 6h, increases in circulating neutrophils and CD43Lo/His48Hi monocytes were observed in rats subjected to longer-duration blast waves. This was accompanied by increases in circulating pro-inflammatory chemo/cytokines KC and IL-6. No changes were observed with shorter-duration blast waves irrespective of overpressure. In all cases, no histological damage was observed in muscle, lung or liver. By 24h post-blast, all inflammatory parameters had normalised. CONCLUSIONS We report the development of a rodent model of primary blast limb trauma that is the first to highlight an important role played by blast wave duration and magnitude in initiating acute inflammatory response following limb injury in the absence of limb fracture or penetrating trauma. The combined biological and mechanical method developed can be used to further understand the complex effects of blast waves in a range of different tissues and organs in vivo.
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Affiliation(s)
| | | | - Hari Arora
- Department of Bioengineering, Imperial College London, UK.
| | | | | | - Mako Itadani
- Department of Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
| | - Anna E Sharrock
- National Heart and Lung Institute, Imperial College London, UK.
| | - David Britzman
- Department of Bioengineering, Imperial College London, UK.
| | | | | | - Sara M Rankin
- National Heart and Lung Institute, Imperial College London, UK.
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12
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Lv J, Ou W, Zou XH, Yao Y, Wu JL. Effect of dexmedetomidine on hippocampal neuron development and BDNF-TrkB signal expression in neonatal rats. Neuropsychiatr Dis Treat 2016; 12:3153-3159. [PMID: 28003751 PMCID: PMC5158139 DOI: 10.2147/ndt.s120078] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The study aimed to explore the effect of dexmedetomidine (DEX) on hippocampal neuron development process and on molecular expression of brain-derived neurotrophic factor (BDNF)-tyrosine receptor kinase B (TrkB) signaling pathway in neonatal rats. The hippocampal neuron cells were isolated from newborn neonatal rats and cultured in vitro. One control group and three treated groups with 1, 10, and 100 μmol/L DEX were used for the study. Cell activity and apoptosis were detected by the MTT and terminal deoxynucleotidyl transferase-mediated biotinylated uridine triphosphate (UTP) nick end labeling assays. The synaptophysin (SYN) and postsynaptic density 95 (PSD95) were detected by quantitative polymerase chain reaction. There was no difference in the viability of neuron cells among the different dose groups of DEX and the control group during days 2-10 (P>0.05). Compared to the control group, there was no significant difference (P>0.05) in the expressions of SYN and PSD95 in the groups treated with 1 and 10 μmol/L DEX, whereas significant difference in the expression was observed in the group treated with 100 μmol/L DEX (P<0.01). Compared with the control group, the expression of BDNF was significantly upregulated (P<0.05) in the group treated with 100 μmol/L DEX. There were no significant differences in TrkB expression among the four groups. The expression of p-N-methyl-D-aspartate receptor increased with an increase in the concentration of DEX; however, only the high dose revealed a significant upregulation compared with the control group. The neuroprotective effect of DEX may be achieved by upregulating the expression of BDNF and phosphorylation level of N-methyl-D-aspartate receptor.
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Affiliation(s)
- Jie Lv
- Department of Anesthesia, Guizhou Medical University Affiliated Hospital, Guiyang, People's Republic of China
| | - Wei Ou
- Department of Anesthesia, Guizhou Medical University Affiliated Hospital, Guiyang, People's Republic of China
| | - Xiao-Hua Zou
- Department of Anesthesia, Guizhou Medical University Affiliated Hospital, Guiyang, People's Republic of China
| | - Yin Yao
- Department of Anesthesia, Guizhou Medical University Affiliated Hospital, Guiyang, People's Republic of China
| | - Jin-Li Wu
- Department of Anesthesia, Guizhou Medical University Affiliated Hospital, Guiyang, People's Republic of China
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13
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Kirihara Y, Takechi M, Kurosaki K, Kobayashi Y, Saito Y, Takeuchi T. Effects of an anesthetic mixture of medetomidine, midazolam, and butorphanol in rats-strain difference and antagonism by atipamezole. Exp Anim 2015; 65:27-36. [PMID: 26424468 PMCID: PMC4783648 DOI: 10.1538/expanim.15-0036] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
An anesthetic mixture of medetomidine (MED), midazolam (MID), and butorphanol (BUT) has
been used in laboratory animals. We previously reported that this anesthetic mixture
produced closely similar anesthetic effects in BALB/c and C57BL/6J strains. We also
demonstrated the efficacy of atipamezole (ATI), an antagonist of MED that produced quick
recovery from anesthesia in mice. Anesthetics have various anesthetic effects among animal
strains. However, the differences in the effects of anesthetic mixtures in rats are
unclear. In the present study, we first examined effects of the abovementioned anesthetic
mixture using three different rat strains: Wistar (WST), Sprague-Dawley (SD), and Fischer
344 (F344). Second, we examined how different dosages and optimum injection timing of ATI
affected recovery from anesthesia in rats. We used the anesthetic score to measure
anesthetic duration and a pulse oximeter to monitor vital signs. We found no significant
differences in anesthetic duration among the three different strains. However, recovery
from anesthesia in the SD strain took significantly longer than in the other strains. The
antagonistic effects of ATI (0.15 mg/kg and 0.75 mg/kg) were equivalent when administered
at 30 min after anesthetic mixture administration. The antagonistic effects of ATI 0.75
mg/kg were stronger than those of ATI 0.15 mg/kg at 10 min after anesthetic mixture
administration. This anesthetic mixture is a useful drug that can induce similar
anesthetic effects in three different strains and has an antagonist, ATI, that makes rats
quickly recover from anesthesia. These results may contribute to the welfare of laboratory
animals.
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Affiliation(s)
- Yumiko Kirihara
- Department of Experimental Animals, Interdisciplinary Center for Science Research, Organization for Research, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan
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14
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Ribeiro PO, Silva HB, Tomé AR, Cunha RA, Antunes LM. Hippocampal long-term potentiation in adult mice after recovery from ketamine anesthesia. Lab Anim (NY) 2015; 43:353-7. [PMID: 25238524 DOI: 10.1038/laban.571] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Accepted: 05/27/2014] [Indexed: 01/23/2023]
Abstract
Ketamine is frequently used to induce analgesia or anesthesia in laboratory animals, but its effects on learning and memory are poorly characterized. Long-term potentiation (LTP) is considered a cellular mechanism for learning and memory. Ketamine administration immediately abolishes hippocampal LTP in vivo, but whether this effect persists is not known. The authors administered one of two doses of ketamine to adult male C57BL/6 mice and measured LTP in hippocampal slices from the mice 24 h later. Neither LTP induction nor LTP maintenance differed significantly in mice that were administered ketamine compared with mice that were administered saline. The findings suggest that a single intraperitoneal dose of ketamine does not persistently alter LTP in adult male mice.
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Affiliation(s)
- Patrícia O Ribeiro
- Centre for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Henrique B Silva
- Centre for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Angelo R Tomé
- 1] Centre for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal. [2] Department of Life Sciences, Faculty of Science and Technology, University of Coimbra, Coimbra, Portugal
| | - Rodrigo A Cunha
- 1] Centre for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal. [2] Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Luís M Antunes
- 1] Laboratory Animal Science, Institute for Molecular and Cellular Biology, Porto, Portugal. [2] Department of Veterinary Sciences, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal
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15
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Mortality associated with using medetomidine and ketamine for general anesthesia in pregnant and nonpregnant Wistar rats. Lab Anim (NY) 2015; 43:208-14. [PMID: 24845007 DOI: 10.1038/laban.517] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 03/07/2014] [Indexed: 11/08/2022]
Abstract
Medetomidine and ketamine are injectable drugs that can be used in combination to induce general anesthesia in rats. After noticing a high incidence of morbidity and mortality in pregnant Wistar rats given medetomidine and ketamine for anesthesia, the authors further investigated the effects of this combination of anesthetic drugs in both pregnant and nonpregnant Wistar rats. The time to recumbency and the duration of general anesthesia were similar between pregnant and nonpregnant rats. Pregnancy status did not affect the rats' pulse rate, respiratory rate, rectal temperature, oxygen saturation or perfusion index during 2 h of anesthesia. Pregnant rats had significantly lower blood glucose concentrations than nonpregnant rats at all time points, though blood glucose concentrations increased in both groups. The mortality rate was ∼15% both for nonpregnant rats and for pregnant rats. Researchers using medetomidine and ketamine to anesthetize Wistar rats should carefully monitor the rats in order to minimize mortality.
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16
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von Kraus LM, Francis JT. Electronically induced contrast enhancement in whisker S1 cortical response fields. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2014:2601-4. [PMID: 25570523 DOI: 10.1109/embc.2014.6944155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The ability of an organism to specifically attend to relevant sensory information during learning and subsequent performance of a task is highly dependent on the release of the neurotransmitter Acetylcholine (ACh). Electrophysiological studies have shown that pairing endogenous ACh with specific visual or auditory stimuli induces long lasting enhancements of subsequent cortical responses to the previously paired stimulus. In this study we present data suggesting that similar effects can be elicited in the rat whisker sensory system. Specifically, we show that pairing whisker deflection with electrical stimulation of the magnocellular basal nucleus (BN: a natural source of cortical ACh) causes an increase in the center-surround contrast of the treated whisker's cortical response field (CRF). Meanwhile, deflections of whiskers distant from the treated whisker show overall increased response magnitudes, but non-significant changes in contrast between principle vs. surround barrel responses. Control trials, in which BN stimulation was not paired with whisker deflection, showed similar lack of contrast enhancement. These results indicate that BN stimulation, paired with incoming whisker information, selectively increases the paired whisker's CRF center-surround contrast, while unpaired BN stimulation causes a more general increases in S1 responsiveness, without contrast modulation. Enhanced control over whisker sensory pathway attentional mechanisms has the potential to facilitate a more effective transfer of desired information to the animal's neural processing circuitry, thereby allowing experimental evaluation of more complex behavior and cognition than was previously possible.
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17
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El-Kammar MH, Gad SB. Antagonism of Detomidine-Induced Sedation, Analgesia, Clinicophysiological, and Hematobiochemical Effects in Donkeys Using IV Tolazoline or Atipamezole. J Equine Vet Sci 2014. [DOI: 10.1016/j.jevs.2014.02.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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18
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Burnside WM, Flecknell PA, Cameron AI, Thomas AA. A comparison of medetomidine and its active enantiomer dexmedetomidine when administered with ketamine in mice. BMC Vet Res 2013; 9:48. [PMID: 23497612 PMCID: PMC3605306 DOI: 10.1186/1746-6148-9-48] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Accepted: 03/06/2013] [Indexed: 11/10/2022] Open
Abstract
Background Medetomidine-ketamine (MK) and dexmedetomidine-ketamine (DK) are widely used to provide general anaesthesia in laboratory animals, but have not been compared directly in many of these species, including rodents. This study aimed to compare the onset and depth of anaesthesia, and changes in vital signs, after intraperitoneal (IP) or subcutaneous (SC) administration of ketamine (75 mg kg-1) combined with medetomidine (1 mg kg-1) or dexmedetomidine (0.5 mg kg-1) using a randomised semi-crossover design with ≥ 48 hours between treatments in 10 male and 10 female mice. Each mouse was anaesthetised twice using the same administration route (IP or SC): once with each drug-ketamine combination. Anaesthetised mice were monitored on a heating pad without supplemental oxygen for 89 minutes; atipamezole was administered for reversal. The times that the righting reflex was lost post-injection and returned post-reversal were analysed using general linear models. Tail-pinch and pedal reflexes were examined using binomial generalized linear models. Pulse rate (PR), respiratory rate (fr), and arterial haemoglobin saturation (SpO2) were compared using generalized additive mixed models. Results There were no significant differences among treatments for the times taken for loss and return of the righting reflex, or response of the tail-pinch reflex. The pedal withdrawal reflex was abolished more frequently with MK than DK over time (P = 0.021). The response of PR and SpO2 were similar among treatments, but fr was significantly higher with MK than DK (P ≤ 0.0005). Markedly low SpO2 concentrations occurred within 5 minutes post-injection (83.8 ± 6.7%) in all treatment groups and were most severe after 89 minutes lapsed (66.7 ± 7.5%). No statistical differences were detected in regards to administration route (P ≤ 0.94). Conclusions This study failed to demonstrate clinical advantages of the enantiomer dexmedetomidine over medetomidine when combined with ketamine to produce general anaesthesia in mice. At the doses administered, deep surgical anaesthesia was not consistently produced with either combination; therefore, anaesthetic depth must be assessed before performing surgical procedures. Supplemental oxygen should always be provided during anaesthesia to prevent hypoxaemia.
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Affiliation(s)
- Wesley M Burnside
- Comparative Biology Centre, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, United Kingdom
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19
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Pharmacological modulation of functional connectivity: α2-adrenergic receptor agonist alters synchrony but not neural activation. Neuroimage 2011; 60:436-46. [PMID: 22209807 DOI: 10.1016/j.neuroimage.2011.12.026] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2011] [Revised: 12/07/2011] [Accepted: 12/14/2011] [Indexed: 11/24/2022] Open
Abstract
Correlative low frequency fluctuations in functional MRI (fMRI) signals across brain regions at rest have been taken as a measure of functional connectivity to map large-scale neural networks; however, the neural origin is still not clear. Receptor-targeted pharmacological manipulation could elucidate the role of neuroreceptor systems in resting-state functional connectivity to provide another perspective on the mechanism. In this study, the dose-dependent effects of an α(2)-adrenergic receptor agonist, medetomidine, on brain activation and functional connectivity were investigated. Forepaw stimulation-induced activation and resting-state fluctuation in the rat somatosensory cortices and caudate putamen were measured using the blood oxygenation level dependent (BOLD) fMRI. The results showed significant dose-dependent suppression of inter-hemispheric correlation but not the amplitude in the somatosensory areas, while the stimulation-induced activation in the same areas remained unchanged. To clarify the potential change in the hemodynamic response caused by the vasoconstrictive effect of medetomidine, the resting perfusion fluctuation was studied by arterial spin labeling and showed similar results as the BOLD. This suggests that the oxygen metabolic rate and hence the neural activity may not be affected by medetomidine but only the synchrony between brain regions was suppressed. Furthermore, no change in functional connectivity with medetomidine dosages was seen in the caudate putamen, a region with much lower α(2)-receptor density. These results indicate that resting-state signal correlation may reflect underlying neuroreceptor activity and a potential role of the adrenergic system in the functional connectivity.
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20
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Canever L, Oliveira L, D'Altoé de Luca R, Correa PTF, de B Fraga D, Matos MP, Scaini G, Quevedo J, Streck EL, Zugno AI. A rodent model of schizophrenia reveals increase in creatine kinase activity with associated behavior changes. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2010; 3:421-7. [PMID: 21270541 PMCID: PMC3154043 DOI: 10.4161/oxim.3.6.13446] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Schizophrenia is a debilitating mental disorder characterized by positive (delusions, hallucinations, disorganized speech) and negative (affective flattering, avolition and social withdrawal) symptoms as well as cognitive deficits. The frequency, severity and topography characterize the disorder as heterogeneous, the pathophysiology of schizophrenia is poorly understood. Sub-anesthetic doses of ketamine produce hyperactivity, stereotypy and abnormal social interaction and it is used as a model of schizophrenia. In this study, we induced an animal model by acute sub-anesthetic doses of ketamine and tested different behavioral parameters. We also evaluated the activity of creatine kinase (CK) in brain of rats treated with ketamine. Our results demonstrated that administration of 10, 25 and 50 mg/kg of ketamine induced an increase of covered distance in habituated and non-habituated rats to the behavioral apparatus. Ketamine administration induced significant social deficits and stereotypic behavioral in all doses tested. Finally we evaluated the effect of different doses of ketamine on creatinine kinase (CK) activity and we observed that CK activity is increased inspecific regions of the brain. Our study suggests that our animal model may be used as a model of schizophrenia and that cerebral energy metabolism might be altered in the brain of schizophrenic patients, probably leading to alterations that might be involved in the pathogenesis of schizophrenia.
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Affiliation(s)
- Leila Canever
- Laboratório de Neurociências, Programa de Pós-Graduação em Ciências da Saúde, Unidade Acadêmica de Ciências da Saúde, Universidade do Extremo Sul Catarinense, Criciúma, SC, Brazil
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21
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Jang HS, Jang IS, Lee MG. The effects of tramadol on electroencephalographic spectral parameters and analgesia in rats. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2010; 14:191-8. [PMID: 20631893 DOI: 10.4196/kjpp.2010.14.3.191] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Revised: 06/10/2010] [Accepted: 06/20/2010] [Indexed: 11/15/2022]
Abstract
The effects of different doses of tramadol on analgesia and electroencephalographic (EEG) spectral parameters were compared in rats. Saline or tramadol 5, 10, 20 or 40 mg/kg was administered. The degree of analgesia was evaluated by tail-flick latency, and the degree of seizure was measured using numerical seizure score (NSS). Additionally, band powers, median power frequency and spectral edge frequency 95 were measured to quantify the EEG response. All doses of tramadol produced spike-wave discharge. Tramadol significantly and dose-dependently increased the analgesia, but these effects did not correspond with the changes in the EEG spectral parameters. NSS significantly increased in the Tramadol 20 and 40 mg/kg treatment groups compared to the Control and TRA5 groups, and two rats given 40 mg/kg had convulsions. In conclusion, tramadol dose-dependently increased the analgesic effect, and the 10 mg/kg dose appears to be a reliable clinical dose for analgesia in rats, but dose-dependent increases in analgesia and seizure severity did not correlate with EEG spectral parameters.
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Affiliation(s)
- Hwan-Soo Jang
- Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu 700-422, Korea
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22
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Williams KA, Magnuson M, Majeed W, LaConte SM, Peltier SJ, Hu X, Keilholz SD. Comparison of alpha-chloralose, medetomidine and isoflurane anesthesia for functional connectivity mapping in the rat. Magn Reson Imaging 2010; 28:995-1003. [PMID: 20456892 DOI: 10.1016/j.mri.2010.03.007] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 01/18/2010] [Accepted: 03/11/2010] [Indexed: 12/19/2022]
Abstract
Functional connectivity measures based upon low-frequency blood-oxygenation-level-dependent functional magnetic resonance imaging (BOLD fMRI) signal fluctuations have become a widely used tool for investigating spontaneous brain activity in humans. Still unknown, however, is the precise relationship between neural activity, the hemodynamic response and fluctuations in the MRI signal. Recent work from several groups had shown that correlated low-frequency fluctuations in the BOLD signal can be detected in the anesthetized rat - a first step toward elucidating this relationship. Building on this preliminary work, through this study, we demonstrate that functional connectivity observed in the rat depends strongly on the type of anesthesia used. Power spectra of spontaneous fluctuations and the cross-correlation-based connectivity maps from rats anesthetized with alpha-chloralose, medetomidine or isoflurane are presented using a high-temporal-resolution imaging sequence that ensures minimal contamination from physiological noise. The results show less localized correlation in rats anesthetized with isoflurane as compared with rats anesthetized with alpha-chloralose or medetomidine. These experiments highlight the utility of using different types of anesthesia to explore the fundamental physiological relationships of the BOLD signal and suggest that the mechanisms contributing to functional connectivity involve a complicated relationship between changes in neural activity, neurovascular coupling and vascular reactivity.
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Affiliation(s)
- Kathleen A Williams
- Department of Radiology, Center for Biomedical Imaging, New York University School of Medicine, New York, NY 10012, USA
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Jang HS, Lee MG. Atipamezole changes the antinociceptive effects of butorphanol after medetomidine-ketamine anaesthesia in rats. Vet Anaesth Analg 2009; 36:591-6. [PMID: 19845932 DOI: 10.1111/j.1467-2995.2009.00497.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To investigate the effects of atipamezole administered before butorphanol, on tail-flick latency (TFL) and also following medetomidine-ketamine anaesthesia in rats. STUDY DESIGN Prospective, randomized experimental study. ANIMALS Thirty-four adult male Sprague-Dawley rats weighing 260-390 g. METHODS TFL in 50 degrees C water was used to measure antinociception. In the first experiment, rats received saline (n = 5) or atipamezole (n = 5) followed by butorphanol treatments. In the second experiment, three groups of rats received saline (n = 8), atipamezole (n = 8) or atimpamezole (n = 8) followed by butorphanol 60 minutes after medetomidine-ketamine administration. RESULTS In the first experiment, butorphanol significantly increased TFL compared to baseline. Atipamezole significantly decreased this effect. In the second experiment, TFL was significantly increased after recovery from medetomidine-ketamine anaesthesia compared to baseline. This was almost completely blocked by atipamezole. Atipamezole with butorphanol after recovery from the anaesthesia significantly reduced TFL compared to saline but still significantly increased TFL compared to the baseline. CONCLUSION AND CLINICAL RELEVANCE Atipamezole attenuated the analgesic effects of butorphanol. When postoperative atipamezole is used to hasten recovery from anaesthesia in rats, it may interfere with the postoperative analgesic effect of butorphanol.
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Affiliation(s)
- Hwan Soo Jang
- Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu, Korea
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