Dopamine and Depression

            In both papers, they were investigating the role dopamine neurons play in depression. While both papers used largely the same tests on mice to measure behavior, there were two tests unique to each paper. In the Tye paper, these were the Forced Swim Test and the Tail-suspension test. In the Chaudhury paper, these were the Social-Defeat stress/social interaction and Elevated Maze tests. This is interesting because in this case the Tye paper used two tests that measure how long until the mouse gives up, but the Chaudhury paper was testing both social avoidance and how long until the mouse gives up, or just if it does. I find it interesting that the Chaudhury paper also chose the social behavior to test, as this is also a symptom of depression in humans, and I feel it would be pertinent to test this in mice as well. I also found the difference between the maze test and the swimming and tail-suspension tests interesting, because the maze test gave the mouse a way out, and measured the delay on the mice after messing up, as opposed to measuring the time until giving up with the swimming and tail tests, where the mouse is put into a situation it can’t get itself out of.

            The two studies had similar results with regards to the sucrose preference test, however. When the phasic stimulation was applied, both tests found a decrease in sucrose preference, which is used as a measure for depressive effect on the mice’s mood. It was worth noting, though, that the Tye paper mentions that there was no difference in the open-field test, but in the Chaudhury paper they don’t mention the results of the open-field test. This would have made it easier to compare the two papers, and see if their results are consistent.