1
|
Ohnesorge N, Wilzopolski J, Steinfath M, Lewejohann L, Banneke S, Heinl C. Assessment of the effect of tricaine (MS-222)-induced anesthesia on brain-wide neuronal activity of zebrafish ( Danio rerio) larvae. Front Neurosci 2024; 18:1456322. [PMID: 39381680 PMCID: PMC11458748 DOI: 10.3389/fnins.2024.1456322] [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: 06/28/2024] [Accepted: 09/12/2024] [Indexed: 10/10/2024] Open
Abstract
Fast and effective anesthesia is the key for refining many invasive procedures in fish and gaining reliable data. For fish as for all vertebrates, it is also required by European law to reduce pain, suffering, and distress to the unavoidable minimum in husbandry and experiments. The most often used substance to induce anesthesia in zebrafish is tricaine (MS-222). When properly prepared and dosed, tricaine causes rapid loss of mobility, balance and reaction to touch. These signs are interpreted as a stage of deep anesthesia although its effects on the central nervous system have not convincingly been shown. Therefore, it might be possible that tricaine first acts only on the periphery, resulting in a paralyzed instead of an anesthetized fish. This has severe implications for animals undergoing procedures. To investigate the effects of tricaine on the central nervous system, we used zebrafish larvae [Tg(elavl3:H2B-GCaMP6s)] at 4 days post fertilization (dpf), expressing a calcium indicator (GCaMP6s) in all neurons, that allows monitoring and quantifying the neuronal activity. After treating larvae with 168 mg/L tricaine, a rapid loss of neuronal activity in the forebrain was observed in confocal microscopy. In contrast, only mild effects were seen in the midbrain and hindbrain. In conclusion, the different larval brain areas showed differences in the sensitivity to tricaine treatment. The effects on the central nervous system are indicative of tricaine's anesthetic function and are consistent with behavioral observations of inactivity and unresponsiveness to touch.
Collapse
Affiliation(s)
- Nils Ohnesorge
- German Centre for the Protection of Laboratory Animals (Bf3R), German Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Jenny Wilzopolski
- German Centre for the Protection of Laboratory Animals (Bf3R), German Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Matthias Steinfath
- German Centre for the Protection of Laboratory Animals (Bf3R), German Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Lars Lewejohann
- German Centre for the Protection of Laboratory Animals (Bf3R), German Federal Institute for Risk Assessment (BfR), Berlin, Germany
- Institute of Animal Welfare, Animal Behavior and Laboratory Animal Science, Freie Universität Berlin, Berlin, Germany
| | - Stefanie Banneke
- German Centre for the Protection of Laboratory Animals (Bf3R), German Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Céline Heinl
- German Centre for the Protection of Laboratory Animals (Bf3R), German Federal Institute for Risk Assessment (BfR), Berlin, Germany
| |
Collapse
|
2
|
Reis TDS, Araújo DBD, Paz CAD, Santos RG, Barbosa ADS, Souza LVD, Deiga YDS, Garcia VLDO, Barbosa GB, Rocha LLD, Hamoy M. Etomidate as an anesthetic in Colossoma macropomum: Behavioral and electrophysiological data complement each other as a tool to assess anesthetic safety. PLoS One 2024; 19:e0305093. [PMID: 39106269 DOI: 10.1371/journal.pone.0305093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 05/24/2024] [Indexed: 08/09/2024] Open
Abstract
The use of anesthetic agents in the management of fish in fish farming or ornamental fish breeding aims to minimize stress and promote animal welfare. Therefore, this study aims to investigate behavioral, electrocardiographic, and ventilatory characteristics of tambaquis exposed to anesthetic baths with etomidate. The study was conducted with juvenile tambaquis (27.38 ± 3.5g) n = 99, at etomidate concentrations of 2-4 mg.L -1, analyzing induction and anesthetic recovery behavior (experiment I), electrocardiogram (experiment II), and opercular movement (experiment III). Fish exposed to high concentrations of etomidate reached the stage of general anesthesia faster, however, the recovery time was longer, characterizing a dose-dependent relationship. Cardiorespiratory analyzes demonstrated a reduction in heart rate (69.19%) and respiratory rate (40.70%) depending on the concentration of etomidate used during anesthetic induction. During the recovery period, there was cardiorespiratory reversibility to normality. Therefore, etomidate proved to be safe as an anesthetic agent for this species at concentrations of 2 to 3 mg.L -1 for short-term anesthesia, but at higher doses the animals showed slow reversibility of anesthesia in a gradual manner and without excitability. The hemodynamic effect due to the rapid decrease in heart rate includes a negative factor of using higher concentrations of etomidate for Colossome macropomum anesthesia.
Collapse
Affiliation(s)
- Thaysa de Sousa Reis
- Laboratory of Pharmacology and Toxicology of Natural Products, Biological Science Institute, Federal University of Pará, Belém, PA, Brazil
| | - Daniella Bastos de Araújo
- Laboratory of Pharmacology and Toxicology of Natural Products, Biological Science Institute, Federal University of Pará, Belém, PA, Brazil
| | - Clarissa Araújo da Paz
- Laboratory of Pharmacology and Toxicology of Natural Products, Biological Science Institute, Federal University of Pará, Belém, PA, Brazil
| | - Rodrigo Gonçalves Santos
- Laboratory of Pharmacology and Toxicology of Natural Products, Biological Science Institute, Federal University of Pará, Belém, PA, Brazil
| | - Anara de Sousa Barbosa
- Laboratory of Pharmacology and Toxicology of Natural Products, Biological Science Institute, Federal University of Pará, Belém, PA, Brazil
| | - Luana Vasconcelos de Souza
- Laboratory of Pharmacology and Toxicology of Natural Products, Biological Science Institute, Federal University of Pará, Belém, PA, Brazil
| | - Yris da Silva Deiga
- Laboratory of Pharmacology and Toxicology of Natural Products, Biological Science Institute, Federal University of Pará, Belém, PA, Brazil
| | - Vera Louzeiro de Oliveira Garcia
- Laboratory of Pharmacology and Toxicology of Natural Products, Biological Science Institute, Federal University of Pará, Belém, PA, Brazil
| | - Gabriela Brito Barbosa
- Laboratory of Pharmacology and Toxicology of Natural Products, Biological Science Institute, Federal University of Pará, Belém, PA, Brazil
| | - Lucas Lima da Rocha
- Laboratory of Pharmacology and Toxicology of Natural Products, Biological Science Institute, Federal University of Pará, Belém, PA, Brazil
| | - Moisés Hamoy
- Laboratory of Pharmacology and Toxicology of Natural Products, Biological Science Institute, Federal University of Pará, Belém, PA, Brazil
| |
Collapse
|
3
|
Jorge S, Félix L, Costas B, Valentim AM. Housing Conditions Affect Adult Zebrafish ( Danio rerio) Behavior but Not Their Physiological Status. Animals (Basel) 2023; 13:ani13061120. [PMID: 36978661 PMCID: PMC10044285 DOI: 10.3390/ani13061120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/15/2023] [Accepted: 03/20/2023] [Indexed: 03/30/2023] Open
Abstract
Zebrafish is a valuable model for neuroscience research, but the housing conditions to which it is exposed daily may be impairing its welfare status. The use of environmental enrichment and the refinement of methodology for cortisol measurement could reduce stress, improving its welfare and its suitability as an animal model used in stress research. Thus, this study aimed to evaluate (I) the influence of different housing conditions on zebrafish physiology and behavior, and (II) skin mucus potential for cortisol measurement in adult zebrafish. For this, AB zebrafish were raised under barren or enriched (PVC pipes and gravel image) environmental conditions. After 6 months, their behavior was assessed by different behavioral paradigms (shoaling, white-black box test, and novel tank). The physiological response was also evaluated through cortisol levels (whole-body homogenates and skin mucus) and brain oxidative stress markers. The results revealed that enriched-housed fish had an increased nearest neighbors' distance and reduced activity. However, no effect on body length or stress biomarkers was observed; whole-body and skin mucus cortisol levels had the same profile between groups. In conclusion, this study highlights the skin mucus potential as a matrix for cortisol quantification, and how housing conditions could influence the data in future studies.
Collapse
Affiliation(s)
- Sara Jorge
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- Laboratory Animal Science, IBMC-Instituto de Biologia Molecular Celular, Universidade do Porto, 4200-135 Porto, Portugal
- Centro Interdisciplinar de Investigação Marinha e Ambiental, (CIIMAR), 4450-208 Matosinhos, Portugal
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, 4050-313 Porto, Portugal
| | - Luís Félix
- Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
- Instituto para a Inovação, Capacitação e Sustentabilidade da Produção Agroalimentar (Inov4Agro), University of Trás-os-Montes and Alto Douro (UTAD), Quinta de Prados, 5000-801 Vila Real, Portugal
| | - Benjamín Costas
- Centro Interdisciplinar de Investigação Marinha e Ambiental, (CIIMAR), 4450-208 Matosinhos, Portugal
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, 4050-313 Porto, Portugal
| | - Ana M Valentim
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- Laboratory Animal Science, IBMC-Instituto de Biologia Molecular Celular, Universidade do Porto, 4200-135 Porto, Portugal
| |
Collapse
|
4
|
Ferreira JM, Jorge S, Félix L, Morello GM, Olsson IAS, Valentim AM. Behavioural Aversion and Cortisol Level Assessment When Adult Zebrafish Are Exposed to Different Anaesthetics. BIOLOGY 2022; 11:1433. [PMID: 36290337 PMCID: PMC9598369 DOI: 10.3390/biology11101433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/16/2022] [Accepted: 09/23/2022] [Indexed: 11/05/2022]
Abstract
The use of zebrafish (Danio rerio) as an animal model is growing and occurs in a wide range of scientific areas. Therefore, researchers need better and more appropriate anaesthetics for stressful and/or painful procedures to prevent unpleasant experiences. Thus, we aimed to study if adult zebrafish displayed aversion-associated behaviours (conditioned place aversion) and alterations in cortisol levels when exposed to equipotent concentrations of MS222, propofol/lidocaine, clove oil, or etomidate. Adult AB zebrafish (mixed-sex, N = 177) were randomly assigned to MS222 (150 mg/L), Propofol/Lidocaine (5 mg/L propofol + 150 mg/L lidocaine), Clove Oil (45 mg/L), or Etomidate (2 mg/L) groups. The conditioned place aversion test was used to assess behavioural aversion. Only etomidate resulted in a similar aversion to the positive control group (HCl; pH = 3). Cortisol levels were measured 5 and 15 min after loss of equilibrium. Etomidate induced low levels of cortisol by impairing its synthesis, whereas all the other groups had similar cortisol levels. Based on our data, etomidate was ruled out as an alternative to MS222, as it showed an aversive profile. The remaining protocols were not innocuous, displaying a weak aversive profile when compared to the positive control. In conclusion, a combination of propofol with lidocaine, clove oil, and MS222 were valid candidates for use as anaesthetic protocols.
Collapse
Affiliation(s)
- Jorge M. Ferreira
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- IBMC—Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
- ICBAS-UP—Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal
- FCUP—Faculdade de Ciências da Universidade do Porto, Universidade do Porto, 4169-007 Porto, Portugal
| | - Sara Jorge
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- IBMC—Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
- ICBAS-UP—Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal
- CIIMAR—Centro Interdisciplinar de Investigação Marinha e Ambiental, 4450-001 Matosinhos, Portugal
| | - Luís Félix
- CITAB—Centro de Investigação e de Tecnologias Agroambientais e Biológicas, Universidade de Trás-os-Montes e Alto Douro, 5001-801 Vila Real, Portugal
| | | | - I. Anna S. Olsson
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- IBMC—Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Ana M. Valentim
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- IBMC—Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| |
Collapse
|
5
|
Ferreira JM, Félix L, Jorge S, Monteiro SM, Olsson IAS, Valentim AM. Anesthesia Overdose Versus Rapid Cooling for Euthanasia of Adult Zebrafish. Zebrafish 2022; 19:148-159. [PMID: 35759370 DOI: 10.1089/zeb.2022.0001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The rapid increase in zebrafish use needs to be accompanied by research into the refinement of procedures. The European (EU) Directive lists three possible euthanasia methods for fish: anesthetic overdose, electrical stunning, and concussion. However, for small fish such as zebrafish, concussion and electrical stunning are difficult to perform, leaving anesthetic overdose as the most used method. Our aim was to test the efficacy and side effects of anesthesia overdose using different anesthetics and the rapid cooling method to euthanize adult zebrafish. Adult mixed-sex AB zebrafish were randomly assigned to: 250 mg/L MS222; 20 mg/L propofol +100 mg/L lidocaine; 6 mg/L etomidate; 50 mg/L clove oil; and rapid cooling (water at 2°C-4°C). Two minutes after opercular movement ceased, animals were transferred into clean water for 20 min and recovery assessed, or decapitated and used for biochemical analysis of the gills, muscle, liver, and brain; for the histological analysis of the gills and muscle; or for the assessment of cortisol levels. No animal recovered; rapid cooling was the quickest and etomidate overdose was the slowest method to cease the opercular movements. There were no major differences between euthanasia methods regarding the biochemical or histological data. Cortisol levels were higher in the rapid cooling group, but only when compared with the propofol/lidocaine group. The use of a physical method of euthanasia, such as rapid cooling, is essential when chemicals, such as anesthetics, may interfere with postmortem analyses. Although anesthetic overdose can be used without major effects on the analyses conducted in this work, rapid cooling can be another option with the advantage of being simple to administer, easily available, affordable, and very quick; this decreases the potential duration of suffering, being more humane. Therefore, a change in EU legislation should be considered to include additional humane options for euthanasia, such as rapid cooling, for zebrafish and other small tropical fish.
Collapse
Affiliation(s)
- Jorge M Ferreira
- Laboratory Animal Science Group, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
| | - Luís Félix
- Laboratory Animal Science Group, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
- Centro de Investigação e de Tecnologias Agroambientais e Biológicas (CITAB), Universidade de Trás-os-Monte e Alto Douro, Vila Real, Portugal
| | - Sara Jorge
- Laboratory Animal Science Group, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
| | - Sandra M Monteiro
- Centro de Investigação e de Tecnologias Agroambientais e Biológicas (CITAB), Universidade de Trás-os-Monte e Alto Douro, Vila Real, Portugal
- Inov4Agro, Institute for Innovation, Capacity Building and Sustainability of Agri-Food Production, Universidade de Trás-os-Monte e Alto Douro, Vila Real, Portugal
| | - I Anna S Olsson
- Laboratory Animal Science Group, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
| | - Ana M Valentim
- Laboratory Animal Science Group, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
- Centro de Investigação e de Tecnologias Agroambientais e Biológicas (CITAB), Universidade de Trás-os-Monte e Alto Douro, Vila Real, Portugal
| |
Collapse
|
6
|
Screening of Anaesthetics in Adult Zebrafish ( Danio rerio) for the Induction of Euthanasia by Overdose. BIOLOGY 2021; 10:biology10111133. [PMID: 34827125 PMCID: PMC8614824 DOI: 10.3390/biology10111133] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/26/2021] [Accepted: 11/01/2021] [Indexed: 11/17/2022]
Abstract
Simple Summary Although zebrafish are used in vast numbers in laboratories all over the world, no consensus has been reached in the scientific community on a humane, consistent, and effective method for euthanasia of this species. Here, we screened commonly used anaesthetic drugs to see if an overdose could induce loss of reflexes of adult zebrafish in a rapid and reliable manner, and without causing distress. The tested anaesthetics were isoeugenol, clove oil, 2-phenoxyethanol, tricaine, benzocaine, lidocaine hydrochloride, and etomidate. We found that lidocaine hydrochloride, buffered with sodium bicarbonate and ethanol to increase its efficacy, induces loss of reflexes in a fast, predictable, and relatively peaceful manner. We recommend its use for adult zebrafish euthanasia. Abstract Zebrafish are often euthanized by overdose of anaesthesia. However, fish may have aversion towards some anaesthetics, and protocol efficacy varies between species. Using wild type adult Danio rerio, we assessed time to loss of opercular beat, righting, and startle reflexes during induction of anaesthetic overdose by either tricaine (0.5 g/L or 1 g/L), benzocaine (1 g/L), 2-phenoxyethanol (3 mL/L), clove oil (0.1%), isoeugenol (540 mg/L), lidocaine hydrochloride (1 g/L), or etomidate (50 mg/L). Initial screening demonstrated that benzocaine and buffered lidocaine hydrochloride achieved the fastest loss of reflexes. The rapid induction times were confirmed when retesting using larger batches of fish. The fastest induction was obtained with 1 g/L lidocaine hydrochloride buffered with 2 g/L NaHCO3, in which all adult zebrafish lost reflexes in less than 2 min. Next, we monitored signs of distress during benzocaine or buffered lidocaine hydrochloride overdose induction. The results indicated that buffered lidocaine hydrochloride caused significantly less aversive behaviors than benzocaine. Finally, we tested several buffers to refine the lidocaine hydrochloride immersion. The most efficient buffer for euthanasia induction using 1g/L lidocaine hydrochloride was 2 g/L NaHCO3 with 50 mL/L 96% ethanol, inducing immobility in less than 10 s and with only 2% of adult zebrafish displaying aversive behaviors during treatment.
Collapse
|