Early developmental effects of propofol exposure in different stages of zebrafish embryos.

The mechanism of action of propofol, a common intravenous anaesthetic, in early life stages is not well understood with contradictory studies showing neurotoxic and neurogenic effects in the developing brain. Zebrafish early life stages have been established as an alternative model for animal experimentation with propofol toxicological effects reported following chronic exposure. Yet, the acute exposure to other anaesthetics has been shown to induce early life stage-dependent toxicological outcomes.

Housing and Husbandry Factors Affecting Zebrafish () Novel Tank Test Responses: A Global Multi-Laboratory Study.

The reproducibility crisis in bioscience, characterized by inconsistent study results, impedes our understanding of biological processes and global collaborative studies offer a unique solution. This study is the first global collaboration using the zebrafish () novel tank test, a behavioral assay for anxiety-like responses. We analyzed data from 20 laboratories worldwide, focusing on housing conditions and experimental setups.

Biological Response Following the Systemic Injection of PEG-PAMAM-Rhodamine Conjugates in Zebrafish.

Numerous therapeutic and diagnostic approaches used within a clinical setting depend on the administration of compounds via systemic delivery. Biomaterials at the nanometer scale, as dendrimers, act as delivery systems by improving cargo bioavailability, circulation time, and the targeting of specific tissues. Although evaluating the efficacy of pharmacological agents based on nanobiomaterials is crucial, conducting toxicological assessments of biomaterials is essential for advancing clinical translation.

Advancing cortisol measurements in zebrafish: Analytical validation of a commercial ELISA kit for skin mucus cortisol analysis.

Cortisol is the main stress biomarker used for zebrafish. However, zebrafish small size made it challenging to extract cortisol without harming or killing the fish. Thus, researchers adopted a terminal method, the trunk cortisol, as standard practice.

Behavioral Profiling of Zebrafish (Danio rerio) Larvae: Activity, Anxiety, Avoidance, and Startle Response.

Apart from morphological, biochemical, and genetic alterations induced by teratogen compounds, there is an increased interest in characterizing behavioral alterations. Behavior is a sensitive parameter that can provide information regarding developmental disruptions non-invasively. Behavioral disturbances interfere with animals' capacity to cope with the environment, having an impact on the organism's life.

Housing Conditions Affect Adult Zebrafish () Behavior but Not Their Physiological Status.

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.

Behavioural Aversion and Cortisol Level Assessment When Adult Zebrafish Are Exposed to Different Anaesthetics.

The use of zebrafish () 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.

Anesthesia Overdose Versus Rapid Cooling for Euthanasia of Adult Zebrafish.

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.

Adult Zebrafish Anesthesia: A Study of Efficacy and Behavioral Recovery of Different Anesthetics.

The use of proper anesthesia in zebrafish research is essential to ensure fish welfare and data reliability. However, anesthesia long-term side effects remain poorly understood. The purpose of this study was to assess anesthesia quality and recovery in adult zebrafish using different anesthetic protocols and to determine possible long-term effects on the fish activity and anxiety-like behaviors after anesthesia.

Malformations and mortality in zebrafish early stages associated with elevated caspase activity after 24 h exposure to MS-222.

Tricaine methanesulfonate (MS-222) is a commonly used anaesthetic agent for immobilization of aquatic species. However, delayed development and malformations have been observed in 24 hpf (hours post-fertilization) zebrafish embryos after long-term immobilization. Still, no comprehensive study has been described regarding zebrafish exposure to MS-222 during the first hours of development, which are one of the most sensitive life stages to toxicants.

MS-222 induces biochemical and transcriptional changes related to oxidative stress, cell proliferation and apoptosis in zebrafish embryos.

MS-222, the most widely used anaesthetic in fish, has been shown to induce embryotoxic effects in zebrafish. However, the underlying molecular effects are still elusive. This study aimed to investigate the effects of MS-222 exposure during early developmental stages by evaluating biochemical and molecular changes.

Review on the use of zebrafish embryos to study the effects of anesthetics during early development.

Over the years, the potential toxicity of anesthetics has raised serious concerns about its safe use during pregnancy. As evidence emerged from research in animal models, showing that some anesthetic drugs are potential teratogenic, the determination of the risk of exposures to anesthetic drugs at early life stages became mandatory. However, due to inaccessibility and ethical constrains related to experimental conditions, the use of early life stages in mammalian models is limited.

MS-222 short exposure induces developmental and behavioural alterations in zebrafish embryos.

MS-222 has been widely used as an anaesthetic in fish, thus, raising the need to infer about its toxicological safety during development. In this study, MS-222 toxicity in zebrafish embryos was evaluated after a 20-min exposure at different stages of development. Embryos exposed during the 256-cell stage displayed an increase in mortality, associated with defective early developmental pathways.

Behavioral Profiling of Zebrafish (Danio rerio) Larvae Following Teratogen Exposure.

Apart from morphological, biochemical, and genetic alterations induced by teratogen compounds, there is an increase interest in characterizing behavioral alterations. Behavior is a sensitive parameter that can provide information regarding developmental disruptions noninvasively, as it is the result of brain processes. Behavioral disturbances interfere with animals' capacity to cope with the environment, having an impact on the organism's life.

Ketamine induction of p53-dependent apoptosis and oxidative stress in zebrafish (Danio rerio) embryos.

Ketamine is a widely used pharmaceutical that has been detected in water sources worldwide. Zebrafish embryos were used in this study to investigate the oxidative stress and apoptotic signals following a 24h exposure to different ketamine concentrations (0, 50, 70 and 90 mg L). Early blastula embryos (∼2 h post fertilisation-hpf) were exposed for 24 h and analysed at 8 and 26 hpf.

Apoptosis-related genes induced in response to ketamine during early life stages of zebrafish.

Increasing evidence supports that ketamine, a widely used anaesthetic, potentiates apoptosis during development through the mitochondrial pathway of apoptosis. Defects in the apoptotic machinery can cause or contribute to the developmental abnormalities previously described in ketamine-exposed zebrafish. The involvement of the apoptotic machinery in ketamine-induced teratogenicity was addressed by assessing the apoptotic signals at 8 and 24 hpf following 20min exposure to ketamine at three stages of early zebrafish embryo development (256 cell, 50% epiboly and 1-4 somites stages).

Morphological and behavioral responses of zebrafish after 24h of ketamine embryonic exposure.

Ketamine, one anesthetic used as an illicit drug, has been detected both in freshwater and marine ecosystems. However, knowledge of its impact on aquatic life is still limited. This study aimed to test its effects in zebrafish embryos by analyzing its time- and dose-dependent developmental toxicity and long-term behavioral changes.

Behavioral alterations of zebrafish larvae after early embryonic exposure to ketamine.

Rationale: Ketamine has been associated with pediatric risks that include neurocognitive impairment and long-term behavioral disorders. However, the neurobehavioral effects of ketamine exposure in early development remain uncertain.

Objectives: This study aimed to test stage- and dose-dependent effects of ketamine exposure on certain brain functions by evaluating alterations in locomotion, anxiety-like and avoidance behaviors, as well as socialization.

Anaesthesia and analgesia in laboratory adult zebrafish: a question of refinement.

Anaesthesia is used daily in fish experimental procedures; however, the use of an inadequate anaesthetic protocol can compromise not only the animal's welfare but also the reliability of results. The use of zebrafish (Danio rerio) in biomedical research has increased in the last decades, highlighting the importance of appropriate anaesthetic regimens for this species. This article reviews the main anaesthetic agents and protocols used in laboratory adult zebrafish, and some of the analgesic methods to be used in this species that still need more research.

Euthanizing zebrafish legally in Europe: Are the approved methods of euthanizing zebrafish appropriate to research reality and animal welfare?

As zebrafish are becoming an increasingly important model organism in biomedical research, the approved methods of euthanizing fish should be expanded to improve both animal welfare and the quality of research. [Image: see text]

Embryonic Stage-Dependent Teratogenicity of Ketamine in Zebrafish (Danio rerio).

Ketamine, a widely used anesthetic, has been shown to have NMDA receptor dependent and independent actions during zebrafish (Danio rerio) embryogenesis. Notwithstanding, the effects of developmental toxicity and the mechanisms of ketamine action on fish embryos are still not well understood, and its implications for early vertebrate development remains to be clarified. In this work, zebrafish embryos were exposed to ketamine (0.

A New Anaesthetic Protocol for Adult Zebrafish (Danio rerio): Propofol Combined with Lidocaine.

Background: The increasing use of zebrafish model has not been accompanied by the evolution of proper anaesthesia for this species in research. The most used anaesthetic in fishes, MS222, may induce aversion, reduction of heart rate, and consequently high mortality, especially during long exposures. Therefore, we aim to explore new anaesthetic protocols to be used in zebrafish by studying the quality of anaesthesia and recovery induced by different concentrations of propofol alone and in combination with different concentrations of lidocaine.

A single intraperitoneal injection of ketamine does not affect spatial working, reference memory or neurodegeneration in adult mice: An animal study.

Background: Ketamine is an anaesthetic and analgesic drug used in research and clinical practice. Little is known about the effects of different doses of this drug on memory and brain cellular death.

Objective: To study the effects of different doses of ketamine on working and reference memory, and neurodegeneration in adult mice.