Dafnia Heartrate Lab report BIO 102 PDF

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BIO 108 LAB:

Effect of Drugs on Daphnia Heart rate APRIL 14TH 2015 Prof. Roger Meservey

Prepared by: Joshua B. Martin

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Daphnia

Effect of Drugs on Daphnia Heart rate Introduction: Daphnia are small aquatic crustaceans widely referred to as water fleas because of their flea like movement. Daphnia are found in many environments ranging from acidic swamps to freshwater lakes. The Daphnia is covered by an exoskeleton that is translucent, this provides a clear view of the Daphnia’s internal structures, specifically the heart. The heart is located dorsally bellow the head. The Daphnia’s average heart rate is approximately 180 bpm under normal conditions, and can reach up to 300 bpm under stress. (2) This Lab is intended to study the effect of drugs on the heart rate of the Daphnia. Specifically; the effect of Epinephrine, Ringers Solution, and Alcohol on the Daphnia’s heart rate under normal constant conditions. I hypothesize that if I add Epinephrine to the Daphnia’s environment the heart rate will increase as the volume of epinephrine increases and time advances. If I add Ringers Solution to the Daphnia’s environment after the exposure to 1 drop of epinephrine for 2 minutes the heart rate will return to baseline as the volume of ringers’ solution increases and time advances but will slow or stop if too much is introduced. If I add Alcohol to the Daphnia’s environment the heart rate will Increase and then sharply decrease to zero. The heart rate can be monitored and counted in many different conditions, and is shown to change with water temperature changes, or changing the type and concentration of chemicals added to the water.(1) With this in mind, the temperature of the water remains constant. Daphnia have shown to be un-effected by being placed in a depression slide and viewed under a microscope (1) Alcohol is a commonly consumed intoxicant, with well-studied cardiovascular effects. The effect of alcohol on the human heart indicates that heart rate increases exponentially with intake until reaching toxic levels, approximately 330g for a 70kg individual. This ratio is used to determine that the Lethal Dose of alcohol for a Daphnia is 0.00471mcg for every mcg. The average weight of a Daphnia is 3.3mcg (3), the dropper used provides many thousands of times the LD in one drop. Epinephrine is a naturally occurring stimulant hormone released under stress, it is shown to increase heart rate in human studies (3) and will have the same effect on the daphnia. Ringers Solution is an isotonic solution made up of salts dissolved in. This solution is meant to reflect the solutes found in animal body fluids. The solution provides the body with necessary electrolytes after periods of stress, in this case, it is used to recover the Daphnia after exposure to Epinephrine.

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Daphnia

Methods and Materials: One Daphnia specimen was placed in a plastic dish with a full 5ml pipet of water from the storage environment. The specimen was immobilized with a plastic cover placed inside the smaller dish containing the specimen. The dish was placed under a dissecting microscope on the lowest light power setting. Baseline heart rate was observed and recorded 3 times over 60 second intervals. Average baseline heart rate was calculated and recorded. One drop of Alcohol was added to the specimen dish and observed. BPM was observed and recorded over 15 second intervals for 6 minutes. A second Daphnia Specimen is collected using the same procedure and method of baseline heat rate data collection as the first trial. One drop of Epinephrine Solution was added to the dish and BPM was observed and recorded over 15 second intervals for 2 minutes. The second specimen was pipetted into a dish prepared with 5ml of Ringers Solution and monitored for 6 minutes with BPM observed and recorded over 15 second intervals. Results: Specimen One Baseline BPM (Normal Conditions) Trial 1 Trial 2 Trial 3 Heart Rate (BPM) 158 140 172

Average 157

Specimen One BPM Exposed to 5ml Alcohol Solution Time

HR/15sec

0:15 0:30 0:45 1:00 1:15 1:30 1:45 2:00 2:15 2:30 2:45 3:00 4:00 5:00 6:00

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38 48 72 52 24 8 0 0 0 0 0 0 0 0 0

BPM

152 192 288 208 96 32 0 0 0 0 0 0 0 0 0

Drug Volume

1 drop 1 drop 1 drop 1 drop 1 drop 1 drop 1 drop 1 drop 1 drop 1 drop 1 drop 1 drop 1 drop 1 drop 1 drop

Daphnia

Results: Specimen Two Baseline BPM (Normal Conditions) Trial 1 Trial 2 Trial 3 Heart Rate (BPM) 148 142 162

Average 151

Specimen Two BPM Exposed to 1 Drop Epinephrine Solution Time

HR/15sec

0:15 0:30 0:45 1:00 1:15 1:30 1:45 2:00

38 38 42 52 68 72 82 80

BPM

152 152 168 208 272 288 328 320

Drug Volume

1 drop 1 drop 1 drop 1 drop 1 drop 1 drop 1 drop 1 drop

Specimen Two BPM Exposed to 5ml Ringers Solution after 2 minutes of Epinephrine Time

HR/15sec

0:15 80 0:30 72 0:45 72 1:00 74 1:15 70 1:30 68 1:45 64 2:00 64 2:15 54 2:30 52 2:45 54 3:00 52 3:15 44 3:30 50 3:45 52 4:00 52 4:15 54 4:30 54 4:45 48 5:00 50 5:15 52 5:30 48 5:45 52 6:00 48 Results: Graphs Jmartin 4

BPM

320 288 288 296 280 272 256 256 216 208 216 208 176 200 208 208 216 216 192 200 208 192 208 192

Drug Volume

5ml 5ml 5ml 5ml 5ml 5ml 5ml 5ml 5ml 5ml 5ml 5ml 5ml 5ml 5ml 5ml 5ml 5ml 5ml 5ml 5ml 5ml 5ml 5ml

Daphnia

Interpretation:

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The data proves my hypothesis, and confirms that the heart rate of the daphnia is unaffected by placement in a plastic dish for observation. As shown by subject number two, the Epinephrine drastically increased Daphnia’s heart rate over the 2 minutes that elapsed. The graph provided by the data shows that after 300BPM (01:45) the heart rate began to drop, from this I hypothesize that with further testing the epinephrine would eventually cause heart failure and kill the specimen. Placing Daphnia number 2 in the Ringer’s Solution proved my second hypothesis. The data shows that by 3 minutes the daphnia was back within normal limits, but remained slightly above the individual baseline for the remaining 3 minutes observed. This may suggest the Daphnia experiences cardiac tissue damage during the exposure to epinephrine leading to a higher baseline heart-rate. Further studies may show a return to baseline or a permanent state of tachycardia. Daphnia number one proved my hypothesis that adding Alcohol to the Daphnia’s environment the heart rate will Increase and then sharply decrease to zero. The data shows a sharp increase in the first 45 seconds to almost 300BPM and then a swift drop to zero over the following 60 seconds. The data collected shows that the lethal dose of alcohol for daphnia is less than 1 drop of the solution used. Conclusion The structure and system of Daphnia is similar to humans, so the effect a drug has on humans can be viewed on a much smaller scale with Daphnia. Alcohol is enjoyed by many, but has risks including death. Epinephrine is a natural substance that raises heart rate in times of stress, and Ringers Solution provides the electrolytes to replenish and aid in recover of many animals.

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References: 1. “Daphnia". Oneida Lake Education Initiative. Stony Brook University. Retrieved April 20th 2015. 2. "Investigating factors affecting the heart rate of Daphnia". Nuffield Foundation. January 25, 2012. Retrieved April 20th 2015. 3. “The Toxicity of Lethal Drugs”. Robert S. Gable. Macroscope. June 2006. Retrieved April 20th 2015.

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Daphnia

NOTES Locomotion of Daphnia: The Daphnia viewed swim with a flea like motion, in bursts. The motion is jerky and it appears to use its 2nd antennae in a downward stroke to propel itself. The antenna are long, segmented and have hair-like branches. The ends of the antenna look like feathers. Internal Movements of immobilized Daphnia: There is movement inside the body cavity of the Daphnia when it is immobilized. On its ventral surface small motions are viewed, upward and down resembling a “doggy-paddle” motion. Dorsally there is a beating heart that constantly beats rhythmically. Daphnia Food: I believe the Daphnia most likely eats small single celled organisms, since the daphnia is a filter feeder it can only consume small foods.

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