Lab

Gerlai Behavioral Genetics Research Laboratory

About the lab

Featured research (5)

Animals are studied en masse by biologists around the world in a variety of biomedical and basic research studies. All this research benefits humankind and animals alike as it tackles a wide variety of problems ranging from those of conservation biology to medicine. Research with animal subjects is a complex endeavor that requires the cooperation and collaboration of a large number of experts, from the principal investigator through technicians and vivarium staff to regulatory experts. The research must be conducted in a humane manner that adheres to acceptable practices regulated by local, state and federal guidelines, rules and the law. In this short opinion article, we examine the current state of affairs regarding how researchers, animal support staff and regulatory experts work together. We pay particular attention to potential conflicts that may arise from the occasionally distinct roles played by those involved in animal research, and we provide some suggestions as short-and long-term remedies that have not been previously discussed in the literature.
The number of zebrafish facilities steadily increases across the Globe. This chapter focusses on a fundamentally important aspect of zebrafish research: how to breed and raise zebrafish. It discusses practical aspects of these questions but also deals with conceptual issues, including whether in establishing zebrafish breeding and rearing methods we should learn from nature, and whether we should standardize our methods. The chapter discusses what we regard as optimal maintenance conditions, e.g. how to prepare adult parental fish for spawning, set up spawning/breeding tanks, how to handle the eggs and rear the young juveniles of zebrafish. The description of methods and maintenance factors includes water chemistry, temperature, filtration, food and feeding methods, among other aspects of breeding and larviculture of the zebrafish. The chapter ends with a short discussion about reproducibility and replicability in research and a note on how zebrafish breeding and larviculture may influence both.
Ethanol consumption is a worldwide problem. Sensitivity to acute effects of ethanol influences the development of chronic ethanol abuse and ethanol dependence. Environmental and genetic factors have been found to contribute to differential effects of acute ethanol. Animal models have been employed to investigate these factors. An increasingly frequently utilized animal model in ethanol research is the zebrafish. A large proportion of ethanol studies with zebrafish have been conducted with adult zebrafish. However, high throughput drug and mutation screens are particularly well adapted to larval zebrafish. These studies are often carried out using the 96-well-plate that allows monitoring large numbers of fish efficiently. Here, we investigate the effects of acute (30 min long) ethanol exposure in 8-day post-fertilization (dpf) old zebrafish. We compare four genetically distinct populations (strains) of zebrafish, measuring numerous parameters of their swim path in two well sizes, i.e., in the 96-well-plate (small volume wells) and in the 6-well-plate (large volume wells). In general, we found that the highest dose of ethanol (1% vol/vol) reduced swim speed, increased duration of immobility, increased turn angle, and increased intra-individual variance of turn angle, while the intermediate dose (0.5%) had a less strong effect, compared to control. However, we also found that these ethanol effects were strain dependent and, in general, were better detected in the larger volume well. We conclude that larval zebrafish are appropriate for quantification of acute ethanol effects and also for the analysis of environmental and genetic factors that influence these effects. We also speculate that using larger wells will likely increase sensitivity of detection and precision in screening applications.
Ethanol is one of the most commonly abused substances in the world, and ethanol abuse and dependence disorders represent major societal problems. However, appropriate treatment is lacking as we still do not fully understand the molecular bases of these disorders. The zebrafish is one of the model organisms utilized for studying such mechanisms. In this study, we examined the effects of acute ethanol administration on the behavior of zebrafish, and we also analyzed correlated gene expression changes using whole-mount in situ hybridization focusing on a number of genes associated with different neurotransmitter systems, stress response, and neuronal activity. We found ethanol treatment to result in hyperactivity and reduced shoal cohesion compared to control. Analysis of c-fos expression demonstrated altered activity patterns in certain brain regions, including intense activation of the mammillary body in zebrafish with acute ethanol treatment. We also found reduced level of gad1b expression in the cerebellum of ethanol treated fish compared to control. However, we could not detect significant changes in the expression level of other genes, including vglut2b, th, crh, hdc, avp, pomc, and galn in ethanol treated fish compared controls. Our results suggest that zebrafish is a promising animal model for the study of mechanisms underlying alcohol induced behavioral changes and alcohol related human disorders.
Fetal Alcohol Spectrum Disorders (FASD) represent a worldwide problem. The severity and types of symptoms of FASD vary, which may be due to the genotype of the fetus and the developmental stage at which the fetus is exposed to alcohol. The most prevalent forms of FASD present less severe symptoms, including behavioral and cognitive abnormalities, and arise from exposure to low amounts of alcohol consumed infrequently. Treating or diagnosing FASD patients has been difficult because we do not understand the mechanisms underlying FASD. Animal models, including the zebrafish, have been suggested to answer this question. Here, we present a proof of concept analysis studying the behavioral effects of embryonic alcohol exposure in one-week old juvenile zebrafish. We exposed zebrafish embryos at one of five developmental stages (8, 16, 24, 32, or 40 hours post-fertilization) to 0% (control) or 1% (vol/vol) ethanol for 2h, and tested the behavior of these fish at their age of 7-9 days post-fertilization. We employed two genetically distinct zebrafish populations, a quasi-inbred AB derivative strain, and a genetically variable WT population. We report significant developmental time and genotype dependent effects of alcohol on certain measures of motor function and/or anxiety-like responses. For example, we found embryonic alcohol exposed AB fish to swim faster, vary their speed more, stop moving more often and turn less compared to control fish, alcohol induced changes that were absent or less robust in WT fish. We conclude that our results open new avenues to the identification of genetic mechanisms that mediate or influence alcohol induced developmental alteration of brain function and behavior, which, on the long run, may allow us to identify diagnostic biomarkers and treatment options for human FASD.

Lab head

Robert Gerlai
Department
  • Department of Psychology

Members (11)

Amanda Facciol
  • University of Toronto
Benjamin Tsang
  • University of Toronto
Samantha Mahabir
  • University of Toronto
Amira Abozaid
  • University of Toronto
Amna Azhar
  • University of Toronto
Zelaikha Najmi
  • University of Toronto
Tulip Marawi
  • University of Toronto
Joshua Hung
  • SickKids Research Institute