Maria Fischer
Contact:
Centre for Organismal Studies
Abteilung Tierphysiologie / Entwicklungsbiologie
Im Neuenheimer Feld 504
Tel: +49-(0)6221/54-6254
Fax:: +49-(0)6221/54-6162
e-Mail: maria.fischer@uni-heidelberg.de
Dissertation title:
Effects of neurotoxic substances on Danio rerio during embryonic development.
Short description:
Some anthropogenic chemicals may exhibit neurotoxic effects. Neurotoxins have disruptive effects on neuronal function even at low concentrations. Tests of neurotoxic effects of these substances are mostly performed on rodents in time-consuming and costly experiments. These include the neurotoxicity study in adult animals (OECD Test No. 424), the developmental neurotoxicity study in embryos and postnatal stages (OECD Test No. 426), and the extended test for reproductive toxicity over more than one generation (OECD Test No. 443). The EU-ToxRisk project is working on further development of testing and risk analysis. The goal includes the experimental animal-free safety assessment of chemicals by linking different in vitro methods bundled in a test battery. The fish embryo of the zebrafish (Danio rerio) represents an ideal model organism for the testing of neurotoxic and developmentally harmful substances due to its uncomplicated husbandry and rapid development. D. rerio does not fall under the European Animal Welfare Act in its larval stages (< 120 h after fertilization) and can thus complement in vitro testing strategies as a highly developed organism. Its natural transparent appearance during the first days allows to monitor changes at different developmental time points. Neurotoxins can cause a variety of disorders and a clear categorization as a neurotoxic substance is not always unambiguous and easy to determine. In my research project I am looking at motoric effects of these substances at early developmental stages of D. rerio. The focus is on the appearance and interaction of motoneurons and the associated muscles. Methods including the established fish embryo acute toxicity (FET) test, antibody staining, histology as well as measurements of behavioural changes can provide conclusions about the nature of the damage.