Abnormal social behavior is a symptom of many human conditions, including Fetal Alcohol Spectrum Disorders (FASD). The zebrafish may be an excellent model to study embryonic alcohol effects, owing to the ease of drug administration. In recent decades, zebrafish have become increasingly popular in behavioral neuroscience, and their elaborate behavioral repertoire can provide insights in brain functioning and social behavior in response to teratogens or pharmaceutical agents. Shoaling is the zebrafish’s most notable behavioral feature, but has not been well characterized. I have started this characterization by describing the ontogeny of shoaling behavior. Embryonic exposure to low doses of ethanol has been shown to impair social behavior without any gross morphological alterations in zebrafish. However, this has not been studied in freely moving groups (shoals). Validation for using a shoaling task in behavioral testing, and potentially for high throughput analyses in the future, hinges on thorough characterization of the behavioral effects, however subtle in alcohol treated zebrafish. In my studies, I have shown that social behavior is impaired in zebrafish in a group setting after one time embryonic ethanol exposure. I have also discovered that this impairment is accompanied by a reduction of dopamine, serotonin, DOPAC and 5HIAA, neurochemicals measured in whole brain samples using HPLC. I have developed refined methods of measuring shoaling behavior in ten member zebrafish groups, laying the foundation for high throughput screening of adult zebrafish. Zebrafish are an economical model, and therefore lend themselves particularly well for high throughput screening. However, current paradigms are still labor intensive and require substantial human capital. By refining current behavioral tests and deploying new analytical tools, high throughput screening is starting to become within reach.

Abnormal social behavior is a symptom of many human conditions, including Fetal Alcohol Spectrum Disorders (FASD). The zebrafish may be an excellent model to study embryonic alcohol effects, owing to the ease of drug administration. In recent decades, zebrafish have become increasingly popular in behavioral neuroscience, and their elaborate behavioral repertoire can provide insights in brain functioning and social behavior in response to teratogens or pharmaceutical agents. Shoaling is the zebrafish’s most notable behavioral feature, but has not been well characterized. I have started this characterization by describing the ontogeny of shoaling behavior. Embryonic exposure to low doses of ethanol has been shown to impair social behavior without any gross morphological alterations in zebrafish. However, this has not been studied in freely moving groups (shoals). Validation for using a shoaling task in behavioral testing, and potentially for high throughput analyses in the future, hinges on thorough characterization of the behavioral effects, however subtle in alcohol treated zebrafish. In my studies, I have shown that social behavior is impaired in zebrafish in a group setting after one time embryonic ethanol exposure. I have also discovered that this impairment is accompanied by a reduction of dopamine, serotonin, DOPAC and 5HIAA, neurochemicals measured in whole brain samples using HPLC. I have developed refined methods of measuring shoaling behavior in ten member zebrafish groups, laying the foundation for high throughput screening of adult zebrafish. Zebrafish are an economical model, and therefore lend themselves particularly well for high throughput screening. However, current paradigms are still labor intensive and require substantial human capital. By refining current behavioral tests and deploying new analytical tools, high throughput screening is starting to become within reach.

Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2017-01-27T09:34:21Z No. of bitstreams: 2 Dissertação - Lara Barroso Brito - 2016.pdf: 19284674 bytes, checksum: 73aa3e2fc34b886b960712220045839d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-01-30T10:01:07Z (GMT) No. of bitstreams: 2 Dissertação - Lara Barroso Brito - 2016.pdf: 19284674 bytes, checksum: 73aa3e2fc34b886b960712220045839d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-01-30T10:01:07Z (GMT). No. of bitstreams: 2 Dissertação - Lara Barroso Brito - 2016.pdf: 19284674 bytes, checksum: 73aa3e2fc34b886b960712220045839d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-03-23 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Pharmaceuticals can be introduced directly into the environmental by household disposal or pharmaceutical industry waste and indirectly through the excretion of humans and animals. Antibiotics are considered emerging contaminants because they are typically present at very low levels in the environmental and their human or ecological health effects are unclear. β-lactams represent more than 70% of antibiotics consumed in Brazil. Thus, in this context, this work evaluated the environmental impact of antibiotic amoxicillin (AMX) in different organisms, considering its presence in water. For that, we used the phytotoxicity test with seeds of tomato (Lycopersicon esculentum), cucumber (Cucumis sativus) and lettuce (Lactuca sativa), brine shrimp toxicity assay (Artemia salina), and embryo-larval toxicity test zebrafish (D. rerio), considering the lethal and sublethal effects and biomarkers determinations. AMX showed no toxicity to seeds of tomato, cucumber and lettuce in relation to seed germination and root elongation endpoints. For microcrustacean A. salina, AMX did not induce significant mortality after 24 h and 48 h exposure (LC50 > 100 mg/L) and it was classified as non-toxic (not categorized) according to the Globally Harmonized System (GHS). AMX also did not cause significant mortality in embryos and larvae zebrafish during 168 h of exposure. It had no significant effect on embryos hatching and larvae equilibrium. However, AMX significantly increased the larvae size at 6.25, 12.5 and 25 mg/L. Catalase (CAT), glutathione S-transferase (GST) and lactate dehydrogenase (LDH) activities in embryos and larvae of zebrafish were inhibited at 12.5 mg/L of AMX, 6.25, 12.5, 25, 50 and 100 mg/L of AMX and 1.5, 3.0, 6.25 and 12.5 mg/L of AMX, respectively. Therefore, AMX showed no significant acute toxicity to tested organisms, but it induced sublethal effects on larvae zebrafish in concentrations greater than those found in the aquatic environment, indicating that long-term chronic exposures must be investigated. / Os fármacos e insumos farmacêuticos podem ser introduzidos no ambiente de forma direta, ou seja, através do descarte doméstico ou por efluentes da indústria farmacêutica, e ainda indiretamente, por meio da excreção humana e animal. Os antibióticos são considerados contaminantes emergentes, uma vez que são detectados em concentrações muito baixas no ambiente e seus efeitos sobre o ambiente e saúde humana permanecem incertos. Os β- lactâmicos representam mais de 70% dos antibióticos consumidos no Brasil. Assim, dentro deste contexto, este trabalho propôs avaliar o impacto ambiental do antibiótico amoxicilina (AMX) em diferentes organismos, considerando a sua presença nos recursos hídricos. Para tanto foram utilizados os ensaios de fitotoxicidade com sementes de tomate (Lycopersicon esculentum), pepino (Cucumis sativus) e alface (Lactuca sativa) e de toxicidade aguda com Artemia salina, assim como o teste com o estágio embriolarval de zebrafish (Danio rerio), considerando os efeitos letais, subletais e atividade de biomarcadores enzimáticos. A AMX não foi tóxica para as sementes de tomate, pepino e alface, não apresentando diferenças estatísticas significativas para os parâmetros de germinação das sementes e do desenvolvimento das raízes. Para o microcrustáceo A. salina, a AMX não induziu mortalidade significativa com valores de CL50 maior que 100 mg/L para 24 h e 48 h de exposição, sendo classificada como não tóxica (não categorizada) de acordo com o Globally Harmonized System (GHS). A AMX não provocou mortalidade significante nos embriões e larvas de zebrafish durante as 168 h de exposição, assim como não alterou significativamente a eclosão dos embriões e o equilíbrio de larvas de zebrafish. Entretanto, o antibiótico aumentou significativamente o tamanho das larvas desse peixe nas concentrações de 6,25; 12,5 e 25 mg/L. As atividades da catalase (CAT), da glutationa Stransferase (GST) e da lactato desidrogenase (LDH) de embriões e larvas de peixezebra foram inibidas significativamente nas exposições à 12,5 mg/L de AMX, 6,25; 12,5; 25; 50 e 100 mg/L de AMX e 1,5; 3,0; 6,25 e 12,5 mg/L de AMX, respectivamente. Portanto, o antibiótico AMX não apresenta toxicidade aguda relevante para os organismos testados, mas causa alguns efeitos subletais em larvas de zebrafish em concentrações superiores às encontradas no ambiente aquático, o que indica a necessidade de se investigar exposições a esse composto a longo prazo.