Behavioral Phenotyping ofCasperMutant and 1-Pheny-2-Thiourea Treated Adult Zebrafish

Abstract

The ability to visualize neural circuits in zebrafish in vivo is one of the most useful aspects of this model organism in neuroscience. To maintain the transparency of embryos, however, drugs, such as 1-pheyl-2-thiourea (PTU) must be added, or researchers can use mutants that do not develop pigment (e.g., the casper). The behavioral characteristics of such strains, however, have not been documented. Here, we tested adult zebrafish from the casper line, as well as wild-type (Tübingen, TU) and wild-types treated as embryos with PTU on three commonly used behavioral endpoints in neuroscience: novel tank test (similar to open-field in rodents), conditioned place preference for nicotine, and social cohesion (using a new method of cluster analysis). We found no differences between the casper and the TU, but the adult TU treated with PTU as embryos showed a marked increase in anxiety during the novel tank test. These data suggest that where possible, labs interested in analysis of developmental processes involved in adult phenotypes should avoid the use of PTU in favor of transparent mutants, such as casper.

Phenylthiourea alters toxicity of mercury compounds in zebrafish larvae

“…However, concentrations of 200 μM PTU are frequently used [14] with such concentrations considered standard protocols [15]. Recently, evidence has been emerging that commonly used doses of PTU may not be as benign as previously had been assumed [16][17][18].…”

Delayed effects of developmental exposure to low levels of the aryl hydrocarbon receptor agonist 3,3′,4,4′,5-pentachlorobiphenyl (PCB126) on adult zebrafish behavior

“…Although developmental dioxin-induced effects on behavior have been demonstrated in mammalian models, the ability to investigate them in zebrafish may prove advantageous for answering this question. Future studies on adult fish that were developmentally exposed to PCB126 or other dioxin-like and non-dioxin-like PCBs will utilize the ever growing diversity of zebrafish behavioral studies, including well established paradigms specific for testing associative (Kalueff and Cachat, 2011b) and non-associative (Wong et al, 2010) learning, as well as other higher cognitive functions (Bailey et al, 2015), evaluating general anxiety levels (Maximino et al, 2010, Parker et al, 2013), and testing the response to stress-inducing situations (Cachat et al, 2010, Eddins et al, 2010). Phenotype anchoring can be done using readily available molecular tools such as gene expression profiling and gene manipulation that will shed light on the relevant molecular pathways and their roles in direct neurodevelopmental toxicity as well as later-life neurobehavioral alterations resulting from developmental exposure.…”

“…The assay was conducted as described previously (Parker et al, 2013) with some modifications. Briefly, a rectangular tank was placed on a grid dividing its bottom surface into 8 equal sections and filled with water up to a height of 6 cm, and a digital video camera (WV-BP330 series, Panasonic Corporation) was secured to a ring stand so that the entire tank could be filmed from above.…”

p-Coumaric Acid Potently Down-regulates Zebrafish Embryo Pigmentation: Comparison ofin vivoAssay and Computational Molecular Modeling with Phenylthiourea

“…But the effect of p-coumaric acid on the zebrafish embryo development and molecular binding study on the tyrosinase enzyme have not been sufficiently investigated yet. In this study, the pcoumaric acid was evaluated and compared with phenylthiourea (PTU), a well-known zebrafish tyrosinase inhibitor (Parker et al, 2013), for their inhibitory effects on zebrafish embryo pigmentation and for whole organism toxicity. We also performed molecular docking studies using the Autodock 4 and Discovery Studio program with the aim of explaining the differences in molecular binding activity of the pcoumaric acid on the tyrosinase enzyme with PTU.…”