Animal Behavioral Model Report

The Sucrose preference test measures a rodents tendency to choose a sucrose solution over a plain water solution. This test is important for understanding anhedonia, which is the decrease in sensitivity to rewards. Anhedonia is a very common symptom in depression. To perform this experiment, the rodent is kept by itself in a cage for 3 days to acclimate to its new environment. Two water bottles are placed in the cage, one containing 2-4 % sucrose solution and the other containing plain water. The positions of the bottles are switched daily to ensure there is no positional bias that the subject might have. This experiment usually runs for around 4 days, and the results are based off of the volume from each bottle consumed. If the rodent has a sucrose preference under 65% they are considered anhedonic. These rodents also usually display decreased latency, increased duration of REM sleep, and decreased sexual activity, all of which are signs of depression in animals. The equipment needed is very simple and requires very little prior knowledge to use. To run this experiment you will need a cage with two water bottle slots, a rat or mouse, water, and some sucrose. 

This Paradigm seems to be valid, the experiment outlines the process and what the variables are, and it seems that there are little to no confounding variables in this experiment. The conclusion of the experiment also seems to follow from the process of the experiment. The experiment would work well in measuring anhedonia as well as the behavioral results from the study. Using this as a basis, you could test the effectiveness of antidepressant drugs on anhedonia.