Desenvolvimento de um teste de neurotoxicidade em Drosophila melanogaster

• Autor(a) principal: Cabrita, Ana Sofia Costa
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/90376
• topic: Neurotoxicity; Drosophila melanogaster; Locomotion; Kinematic parameters; Neurotoxicidade; Locomoção; Parâmetros cinemáticos.; Domínio/Área Científica::Ciências Médicas

Every year new products reach the markets after being tested for the presence of dangerous substances. These items are assessed in accordance with the laws and parameters put in place. However, several restrictions are outdated and some are dangerously vague. Neurotoxicity and developmental neurotoxicity are two parameters that have not gathered much notice, although in recent years there has been a boost in awareness regarding these topics. Therefore, new tests and models are required to provide answers to these demands. One of these models is the fruit fly Drosophila melanogaster, because of its ease to manipulate and maintain, with a highly studied nervous system and a large set of stereotypical behaviors easily quantifiable. In more recent years it has also been used to model neurodegenerative diseases and toxicity assays. These tests usually focus on cytotoxicity in part due to the difficulty in identifying neurotoxicity. Motor performance is a different approach to judge this specific kind of toxicity after the fly has been exposed to the compounds from the embryonic stage. A variation in the kinematic parameters of the fly would indicate compound-induced neurological alterations. Here we tested this approach in the following compounds: Toluene, a common industrial solvent; the pesticide Chlorpyrifos, both known to be neurotoxic; and the amino acid β-N-methylamino-L-alanine (LBMAA), a compound still questioned about its neurotoxic effects. Our results indicate that fruit flies generally display a dose-dependent response to the tested compounds. Importantly, intermediate concentrations allow a more in-depth study of kinematic features and motor-neuron projections, allowing measuring the neurotoxicity of the compounds. Moreover, all the flies that came in contact with the compounds presented alterations of locomotion, with Toluene results focused on stability parameters and Chlorpyrifos on stability and step parameters. However, the most substantial results were from LBMAA with difference in almost all of the parameters.