Caffeine is one of the most popular psychostimulant drugs worldwide. Its effects are exerted through a variety of complex mechanisms, apparently primarily via interactions with adenosine A1 and A2A receptors. This drug has also been proven to elicit neuroprotective responses in a number of different brain disorders of the Central Nervous System (CNS), as well as provide enhancement of cognitive abilities. Moreover, a biphasic set of functional and structural neurological changes are often found in these receptors among diverse vertebrates. I investigated the effects of chronic caffeine exposure on functional recovery of the dorsal light reflex (DLR) in hemilabyrinthectomized common goldfish, Carassius auratus. In this lesion model the unilateral removal of vestibular organs results in the temporary loss of gravitational regulated postural control, which over time corrects itself by a vestibular compensation (VC) mechanism and can be quantified via the DLR. We compared the functional recovery over 24 post -surgery days in goldfish continuously held in a caffeine solution of 2.5mg/L (n=10), 5.0mg/L (n=10), 10.0mg/L (n=11) or a control 0.0mg/L (n=9). Compared to a sham surgery group (n=11), statistically significant changes in the DLR of all hemilabyrinthectomized goldfish was observed on day 1. The control group recovered over the study period by approaching but not entirely reaching sham surgery DLR. The 2.5mg/L and 5.0mg/L groups initiated postural recovery similar to the controls, but then regressed to a stronger DLR. Beginning on day 10 the caffeine groups deviated from the control and all three experimental caffeine groups were statistically different from the control group on days 15-24. Results suggest early caffeine exposure may be innocuous; however, chronic exposure inhibits the functional recovery process.

Made available in DSpace on 2017-07-10T18:13:29Z (GMT). No. of bitstreams: 1 Juliana Mara Costa.pdf: 556873 bytes, checksum: b4d6f1321099600920caa72a0df212c3 (MD5) Previous issue date: 2012-07-09 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Nutrition has a fundamental importance for the success of fish farming, considering that it represents the majority costs of production. Considering that the fish absorb various nutrients in the water, although the amount of phosphorus absorbed is not sufficient for its proper development, having the need to supply it in diet. Therefore, the present work aimed to evaluate the performance, chemical composition and plasmatic phosphorus response of the different levels of phosphorus inclusion on goldfish (Carassius auratus) diets. Were used 200 fry with weight, standard and total initial length of 3,11±0,50g; 3,68±0,23cm and 5,11±0,31cm, respectively. The fish were distributed in a completely randomized design with five treatments and four replicates in 20 cages of 0,15 m3 of useful volume, made of mesh shade and installed in a circular tank. The experimental lasted for 8 months, being divided into three phases. The diets were formulated with 30% of crude protein and 2900 kcal.kg-1 of digestible energy, isoproteic and isocaloric, with 0,65, 0,80, 0,95, 1,10 e 1,25% of phosphorus concentration. The fed was realized four times a day until the fish apparent satiation. The physical and chemical water variables such as pH, electrical conductivity and dissolved oxygen were measured weekly and the temperature was monitored four times a day. At the end of the experiment, the fish were fasted for 24 h, to empty the gastrointestinal tract. After this procedure, were collected and anesthetized with solution of benzocaine (75 mg.L-1) during 15 minutes, and after that the fish were weighed and measured. Was carried out the collection of 1,0 mL of fish blood via caudal vein using disposable syringes containing EDTA (10%). For determination of phosphorus in the blood, the phosphomolybdate colorimetric method was used. It is concluded that, for the first phase, on experimental conditions, the best results of weight gain were obtained for the phosphorus inclusion levels of 0,95 and 1,10%, (P<0,05) does not influence this parameter in the other phases. For feed conversion, the best index was obtained for the phosphorus inclusion levels of 1,25%, when evaluated the complete experimental period. There was no difference in phosphorus concentration in the fish plasm. The highest value of mineral matter in the chemical composition of the animals was observed for 1,25% of phosphorus supplement (P<0,05). / A alimentação balanceada é de fundamental importância para o sucesso da piscicultura, tendo em vista que representa a maior parte dos custos de produção. Considerando que os peixes possuem a capacidade de absorver certos minerais presentes na água, a quantidade de fósforo absorvida não é suficiente para o adequado desenvolvimento dos animais, quando cultivados, havendo a necessidade de seu fornecimento pela dieta. Assim, este trabalho teve como objetivo avaliar a resposta em parâmetros zootécnicos, de composição bromatológica e de fósforo plasmático à inclusão de diferentes níveis de fósforo em dietas para kinguio (Carassius auratus). Foram utilizados 200 alevinos com peso, comprimento padrão e total inicial médio de 3,11±0,50g, 3,68±0,23cm e 5,11±0,31cm, respectivamente. Os indivíduos foram distribuídos em delineamento inteiramente casualizado, com cinco tratamentos e quatro repetições, em 20 tanques-rede de 0,15 m3 de volume útil cada, confeccionados em malha sombrite e instalados em um tanque circular de alvenaria. O período experimental teve duração de 8 meses, sendo subdividido em 3 fases, utilizando a mesma dieta mas com variação da temperatura. As dietas foram formuladas com 30% de proteína bruta e 2900 kcal.kg-1 de energia digestível, isoproteicas e isoenergéticas, com concentrações de: 0,65, 0,80, 0,95, 1,10 e 1,25% de fósforo. O arraçoamento foi realizado quatro vezes ao dia, ad libitum, até a saciedade aparente dos peixes. As variáveis físicas e químicas da água, pH, condutividade elétrica e oxigênio dissolvido, foram mensuradas semanalmente e a temperatura monitorada diariamente, quatro vezes ao dia. Ao final do experimento, os peixes foram mantidos em jejum por 24 h, para esvaziamento do trato gastrointestinal. Após este procedimento, foram coletados e anestesiados com solução de benzocaína (75 mg.L-1) durante 15 minutos e, posteriormente, pesados e medidos. Realizou-se a coleta de 1,0 mL sangue por peixe via punção da veia caudal utilizando-se seringas descartáveis contendo solução de EDTA (10%). Para determinação do fósforo no sangue, utilizou-se o método fosfomolibdato colorimétrico. Concluiu-se que, para a fase I, nas condições experimentais, obteve-se o melhor resultado para ganho em peso para os níveis de 0,95 e 1,10% de fósforo (P<0,05), não influenciando este parâmetro nas demais fases. Para conversão alimentar aparente, o melhor índice foi obtido para o nível de 1,25% de fósforo na dieta, quando avaliado o período experimental completo. Não houve diferença na concentração de fósforo plasmático dos peixes. O maior valor de matéria mineral na composição bromatológica dos animais foi verificado para 1,25% de suplementação de fósforo (P<0,05).