Divergent action of fluoxetine in zebrafish according to responsivity to novelty

Débora Fior,João Gabriel Santos Da Rosa,Heloísa Helena De Alcântara Barcellos,Michele Fagundes,Gessi Koakoski,Leonardo José Gil Barcellos,Murilo Sander De Abreu,Fernanda Dametto,Angelo Piato,Renan Idalencio

doi:10.1038/s41598-018-32263-y

Abstract

Here we show that the novel object recognition test can discriminate between high (HRN, neophobic) and low (LRN, neophilic) novelty responders in zebrafish populations. Especially when we observe the latency to the first entry in the novel object zone, zebrafish did not maintain these behavioral phenotypes in sequential tests and only the HRN group returned to their initial responsive behavior when exposed to fluoxetine. Our results have important implications for behavioral data analysis since such behavioral differences can potentially increase individual response variability and interfere with the outcomes obtained from various behavioral tasks. Our data reinforce the validity of personality determination in zebrafish since we show clear differences in behavior in response to fluoxetine.

Highlights

We show that the novel object recognition test can discriminate between high (HRN, neophobic) and low (LRN, neophilic) novelty responders in zebrafish populations
In our initial novel objecting recognition (NOR) testing, 38 zebrafish that did not explore the novel object were classified as high responders to novelty (HRN, neophobic) and 38 zebrafish that spent more time around the novel object, as low responders to novelty (LRN, neophilic) (Fig. 1A)
HRN fish acutely exposed to FLU did not visit the novel object at any time whereas HRN unexposed to FLU showed an increase in time spent in the novel object zone

Summary

Introduction

We show that the novel object recognition test can discriminate between high (HRN, neophobic) and low (LRN, neophilic) novelty responders in zebrafish populations. Zebrafish (Danio rerio) are small and robust fish with a fast embryonic/larval development and are maintained in high quantities[1] Due to these characteristics and their high genetic homology with humans[2], this model organism is widely used in a variety of research fields, such as neuroscience, pharmacology, and genetics[3,4]. The evaluation of the zebrafish behavioral repertoire has become a strong research tool for biomedical research[5] This species presents complex behavior and relative social interactions. Previous studies have reported that shy zebrafish show low exploratory behavior[14], while bold fish are highly explorative and increase their interactions with novel objects[15]. Here we evaluate individual zebrafish according to their reactivity to novelty and investigate whether FLU modulates these personality traits

Methods

Results

Conclusion