Eli Utterback

Three-Dimensional Neurophenotyping of Adult Zebrafish Behavior

The use of adult zebrafish (Danio rerio) in neurobehavioral research is rapidly expanding. The present large-scale study applied the newest video-tracking and data-mining technologies to further examine zebrafish anxiety-like phenotypes. Here, we generated temporal and spatial three-dimensional (3D) reconstructions of zebrafish locomotion, globally assessed behavioral profiles evoked by several anxiogenic and anxiolytic manipulations, mapped individual endpoints to 3D reconstructions, and performed cluster analysis to reconfirm behavioral correlates of high- and low-anxiety states. The application of 3D swim path reconstructions consolidates behavioral data (while increasing data density) and provides a novel way to examine and represent zebrafish behavior. It also enables rapid optimization of video tracking settings to improve quantification of automated parameters, and suggests that spatiotemporal organization of zebrafish swimming activity can be affected by various experimental manipulations in a manner predicted by their anxiolytic or anxiogenic nature. Our approach markedly enhances the power of zebrafish behavioral analyses, providing innovative framework for high-throughput 3D phenotyping of adult zebrafish behavior.

Characterization of behavioral and endocrine effects of LSD on zebrafish

Lysergic acid diethylamide (LSD) is a potent hallucinogenic drug that strongly affects animal and human behavior. Although adult zebrafish (Danio rerio) are emerging as a promising neurobehavioral model, the effects of LSD on zebrafish have not been investigated previously. Several behavioral paradigms (the novel tank, observation cylinder, light-dark box, open field, T-maze, social preference and shoaling tests), as well as modern video-tracking tools and whole-body cortisol assay were used to characterize the effects of acute LSD in zebrafish. While lower doses (5-100 microg/L) did not affect zebrafish behavior, 250 microg/L LSD increased top dwelling and reduced freezing in the novel tank and observation cylinder tests, also affecting spatiotemporal patterns of activity (as assessed by 3D reconstruction of zebrafish traces and ethograms). LSD evoked mild thigmotaxis in the open field test, increased light behavior in the light-dark test, reduced the number of arm entries and freezing in the T-maze and social preference test, without affecting social preference. In contrast, LSD affected zebrafish shoaling (increasing the inter-fish distance in a group), and elevated whole-body cortisol levels. Overall, our findings show sensitivity of zebrafish to LSD action, and support the use of zebrafish models to study hallucinogenic drugs of abuse.

Pharmacological modulation of anxiety-like phenotypes in adult zebrafish behavioral models.

Zebrafish (Danio rerio) are becoming increasingly popular in neurobehavioral research. Here, we summarize recent data on behavioral responses of adult zebrafish to a wide spectrum of putative anxiolytic and anxiogenic agents. Using the novel tank test as a sensitive and efficient behavioral assay, zebrafish anxiety-like behavior can be bi-directionally modulated by drugs affecting the gamma-aminobutyric acid, monoaminergic, cholinergic, glutamatergic and opioidergic systems. Complementing human and rodent data, zebrafish drug-evoked phenotypes obtained in this test support this species as a useful model for neurobehavioral and psychopharmacological research.

Modeling seizure-related behavioral and endocrine phenotypes in adult zebrafish

Larval zebrafish (Danio rerio) have recently been suggested as a high-throughput experimental model of epilepsy-related pathogenetic states. Here we use adult zebrafish to study behavioral symptoms associated with drug-evoked seizures. Experimental epilepsy-like states were evoked in zebrafish by exposure for 20min to three chemoconvulsant drugs: caffeine (250mg/L; 1.3mM), pentylenetetrazole (1.5g/L; 11.0mM) and picrotoxin (100mg/L; 0.17mM). Fish behavior was analyzed using manual and video-tracking methods (Noldus Ethovision XT7). Compared to their respective controls, all three drug-treated groups showed robust seizure-like responses (hyperactivity bouts, spasms, circular and corkscrew swimming) accompanied by elevated whole-body cortisol levels (assessed by ELISA). In contrast, control fish did not display seizure-like behaviors and had significantly lower cortisol levels. Paralleling behavioral and endocrine phenotypes observed in clinical and rodent studies, our data implicates adult zebrafish as an emerging experimental model for epilepsy research.

Behavioral effects of MDMA ('ecstasy') on adult zebrafish.

3,4-Methylenedioxymethamphetamine (MDMA, ‘ecstasy’) is a potent psychedelic drug inducing euphoria and hypersociability in humans, as well as hyperactivity and anxiety in rodents. Adult zebrafish (Danio rerio) have become a widely used species in neurobehavioral research. Here, we explore the effects of a wide range (0.25–120 mg/l) of acute MDMA doses on zebrafish behavior in the novel tank test. Although MDMA was inactive at lower doses (0.25–10 mg/l), higher doses reduced bottom swimming and immobility (40–120 mg/l) and impaired intrasession habituation (10–120 mg/l). MDMA also elevated brain c-fos expression, collectively confirming the usage of zebrafish models for screening of hallucinogenic compounds.

Deconstructing Adult Zebrafish Behavior with Swim Trace Visualizations

Three-dimensional reconstruction is a method of qualifying the behavioral activity of several animals including mice, rats, and zebrafish. This method allows for measuring behavioral endpoint data on two types of tracking planes (temporal and spatial). Temporal tracking measures the activity of a subject across time while spatial tracking measures the activity of a subject in a specific area of the experimental arena as such. Data representation over 3D visual trajectory reconstruction is a robustly advantageous method of behavioral phenotyping. Digital video-tracking and analysis eliminates the inaccuracies of manual tracking and allows for improved investigation of behavioral activity at specific points in time or specific areas of

Intraperitoneal Injection as a Method of Psychotropic Drug Delivery in Adult Zebrafish

Zebrafish behavioral phenotypes are often evaluated in response to pharmacological modulation by various psychotropic drugs. An important step in this process is the method of drug administration. While the most popular drug administration technique in zebrafish research is by immersion, systemic intraperitoneal injection is another effective alternative. This method is useful for drugs that are difficult to dissolve in water, or which require a better control over the amount of drug delivered to an individual animal. Here we outline a simple protocol for the intraperitoneal injection of drugs in adult zebrafish.

Phenotyping of Zebrafish Homebase Behaviors in Novelty-Based Tests

Various novelty-based assays used to quantify zebrafish (Danio rerio) behavior show a striking similarity to behavioral responses in rodents. Exposed to the open field test, zebrafish establish overt homebases demonstrating clear preference for a particular area of the tank. This behavior aims to establish a “safe zone” that zebrafish can familiarize themselves with and feel secure in, and is similar to homebase behaviors of various laboratory rodent species. Here we outline a simple protocol for homebase phenotyping

Modeling Mouse Anxiety and Sensorimotor Integration: Neurobehavioral Phenotypes in the Suok Test

Animal behavioral tests are useful tools for modeling complex human brain disorders. The Suok test (ST) is a relatively new behavioral paradigm that simultaneously examines anxiety and neurological/vestibular phenotypes in rodents. The novelty and instability of the ST apparatus induces anxiety-related behavior in mice, whereas the elevation of the horizontal rod allows for the assessment of motor and neurological phenotypes. This chapter discusses the utility of the ST in detecting mouse anxiety, habituation, exploration, motorisensory deficits, and the interplay between these domains. With a growing number of laboratories using this model, a detailed protocol for the ST behavioral analysis (with a focus on video-tracking tools and novel applications) is also provided.