To Study The Effect Of Daphnia And Stimmutant

A vital "knowledge gap" is addressed in this experiment, that is to study the effect of stimulants and depressants, such as ethanol, melatonin, epinephrine, and dopamine on HR, individually and in a mixture. Said depressant and stimulant chemicals were administered to daphnia individually and afterwards, in combinations. The motivation for research in this area was to explore whether two select depressants or stimulants when administered together have a synergistic, antagonistic or no effect on HR. Data was determined in the form of Beats Per Minute (BPM). The data was analyzed by plotting the calculated BPM for each test solution from each daphnia. This study was designed to discover the effect of the chemicals on daphnia HR. The results of
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Daphnia are grown as fish food, and used to test ecotoxicity. Ecotoxicology is defined as, "the branch of toxicology concerned with the study of toxic effects, caused by natural or synthetic pollutants, to the constituents of ecosystems, animal (including human), vegetable and microbial, in an integral context” (Truhaut, 1977). The experiment discussed in this lab report was performed on daphnia, exploiting their transparency which renders them the ideal organism, to test effects of various stimulus on cardiac activity. Past research studies have found ethanol to produce a depressant effect, one similar to the depressant effects of melatonin, and GABA. In contrast, Corotto (2010) has experimented on stimulants, e.g. nicotine, and found an approximate 20% increase in HR. The data presented in this lab report was observed manually. In this experiment, cardiac activity is being determined via measurement of i.e. heart rate. (HR) For this experiment, the daphnia was subjected to different chemicals via submersion. These chemicals were used as stimuli to prompt altered cardiac activity. The purpose of this experiment, is to test whether two select depressants or stimulants, when administered together, produce a synergistic, antagonistic or no effect on
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melatonin and ethanol, will produce a depressant effect on cardiac activity, i.e. decrease HR. It is predicted that stimulant chemicals, e.g. epinephrine and dopamine, will produce a stimulant effect on cardiac activity, i.e. increase HR. It is predicted that the two stimulant, when administered together, will produce a synergistic effect on HR, i.e. increase HR more than in comparison to when administered individually. Additionally, the two depressants, when administered together, will produce a synergistic effect on HR, i.e. decrease HR more than in comparison to when administered individually. Lastly, when the depressant and stimulant are administered to the Daphnia magna in combination, an antagonistic effect will be observed, i.e. the depressant and stimulant chemicals will negate each other resulting in HR within 5% deviation of the base line daphnia