Comparative Analyses of Zebrafish Anxiety-Like Behavior Using Conflict-Based Novelty Tests

Modeling of stress and anxiety in adult zebrafish (Danio rerio) is increasingly utilized in neuroscience research and central nervous system (CNS) drug discovery. Representing the most commonly used zebrafish anxiety models, the novel tank test (NTT) focuses on zebrafish diving in response to potentially threatening stimuli, whereas the light-dark test (LDT) is based on fish scototaxis (innate preference for dark vs. bright areas). Here, we systematically evaluate the utility of these two tests, combining meta-analyses of published literature with comparative in vivo behavioral and whole-body endocrine (cortisol) testing. Overall, the NTT and LDT behaviors demonstrate a generally good cross-test correlation in vivo, whereas meta-analyses of published literature show that both tests have similar sensitivity to zebrafish anxiety-like states. Finally, NTT evokes higher levels of cortisol, likely representing a more stressful procedure than LDT. Collectively, our study reappraises NTT and LDT for studying anxiety-like states in zebrafish, and emphasizes their developing utility for neurobehavioral research. These findings can help optimize drug screening procedures by choosing more appropriate models for testing anxiolytic or anxiogenic drugs

Divergent effect of fluoxetine on the response to physical or chemical stressors in zebrafish

Fluoxetine is a selective serotonin reuptake inhibitor that increases serotonin concentration in the central nervous system and modulates various systems, including the control of sympathetic outflow and the hypothalamus–pituitary–adrenal. However, it is not yet established whether fluoxetine can modulate the responses to stressors stimulants (physical or chemical) that trigger cortisol response in zebrafish. We demonstrate that fluoxetine blunts the response to physical stress, but not to chemical stress

Understanding Zebrafish Cognition

Zebrafish (Danio rerio) are rapidly becoming a popular model organism in translational and cognitive neuroscience research. Both larval and adult zebrafish continue to increase our understanding of cognitive mechanisms and their genetic and pharmacological modulation. Here, we discuss the developing utility of zebrafish in understanding cognitive phenotypes and their deficits, relevant to a wide range human brain disorders. We also discuss the potential of zebrafish models for high-throughput genetic mutant and small molecule screening (e.g., amnestics, cognitive enhancers, neurodevelopmental/neurodegenerative drugs), which becomes critical for identifying novel candidate genes and molecular drug targets to treat cognitive deficits. In addition to discussing the existing challenges and future strategic directions in this field, we emphasize how zebrafish models of cognitive phenotypes continue to form an interesting and rapidly emerging new field in neuroscience

Zebrafish models of autism spectrum disorder

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder characterized by motor, social and cognitive deficits that develop early during childhood. The pathogenesis of ASD is not well characterized and involves a multifaceted interaction between genetic, neurobiological and environmental factors. Animal (experimental) models possess evolutionarily conserved behaviors and molecular pathways that are highly relevant for studying ASD. The zebrafish (Danio rerio) is a relatively new animal model with promise for understanding the pathogenesis of complex brain disorders and discovering novel treatments. As a highly social and genetically tractable organism, zebrafish have recently been applied to model a variety of deficits relevant to ASD. Here, we discuss the developing utility of zebrafish models of ASD, as well as current behavioral, toxicological and genetic models of ASD, and future directions of research in this field. © 2017 Elsevier Inc

Zebrafish Models of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder characterized by motor, social and cognitive deficits that develop early during childhood. The pathogenesis of ASD is not well characterized and involves a multifaceted interaction between genetic, neurobiological and environmental factors. Animal (experimental) models possess evolutionarily conserved behaviors and molecular pathways that are highly relevant for studying ASD. The zebrafish (Danio rerio) is a relatively new animal model with promise for understanding the pathogenesis of complex brain disorders and discovering novel treatments. As a highly social and genetically tractable organism, zebrafish have recently been applied to model a variety of deficits relevant to ASD. Here, we discuss the developing utility of zebrafish models of ASD, as well as current behavioral, toxicological and genetic models of ASD, and future directions of research in this field

Development and application of a bioeconomic efficiency index for beef cattle production in Rio Grande do Sul, Brazil

An index was developed to estimate the bioeconomic efficiency of production systems, identifying alternative scenarios that could improve their efficiency, and building isoefficiency relations in beef cattle production systems in Rio Grande do Sul. The concept of return on investment was used to develop the indicator. Scenarios regarded as efficient showed values higher than 3. The bioeconomic efficiency index for beef cattle production in the theoretical reference scenario was considered inefficient. At least four modifications in the variables method made it a bioeconomically efficient activity. These circumstances were studied using sensitivity analyses, with theoretical changes in the scenarios by changing variables two by two, while the others were kept constant. In Rio Grande do Sul, alternatives that make the activity efficient were identified by changing productivity, production cost, land price and product price. Isoefficiency relationships were identified in other scenarios. The application of this indicator in other agricultural activities, as well as the design of bioefficiency studies including both environmental and social welfare characteristics are recommended

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora