Department Environmental Toxicology

Behavioral ecotoxicology

The zebrafish is commonly used in ecotoxicological testing, and, due to shared brain features, such as signaling pathways, is also becoming a model for human toxicology. Testing for behavioral effects of environmental stressors is a non-invasive integrative method with high sensitivity, perfectly suited for testing non-lethal effects of different environmental stressors at low effective doses. The behavioral nature of the test requires that live fish are used, with no obligation of ending their lifes after the test is completed.

In this context, we developed two projects: one for characterizing toxicokinetics and behavioural effects of psychoactive drugs in the zebrafish larvae and the second one to investigate effects of  neurologically active compounds on zebrafish.  


Characterizing toxicokinetics and behavioural effects of psychoactive drugs in the zebrafish larvae

In this project we evaluate the relevance and effectiveness of zebrafish-based test system for prediction of human responses to psychoactive drugs by simultaneously assessing their behavioral effects and toxicokinetic profiles. We use unique spectrum of approaches for assessing toxicokinetics such as liquid- chromatography-tandem mass spectrometry (LC-MS/MS) in conjunction with toxicokinetic modelling and matrix assisted laser desorption and ionization mass spectrometry imaging (MALDI-MSI). In a project where we assessed effects of cocaine in zebrafish larvae, we show the importance of studying toxicokinetics while assessing drugs in this model. We have seen here that upon cocaine exposure, zebrafish larvae show a different behavioral response and toxicokinetic pattern compared to humans.   


Effects of neurologically active compounds on zebrafish

In this second project we investigate the effect of citalopram, an antidepressant present in Swiss water, at environmentally relevant concentration on zebrafish. The aim is to analyse how citalopram alters behavioural activity and the nervous system during early life stages and try to establish functional links between gene/protein expression and behavioural disruption in locomotion. This study will lead to improved understanding of citalopram action on fish and could potentially be developed into large scale screening for other aquatic pollutants.