Week 1 Santarelli & Bessa

While both Bessa and Santarelli author papers on studies of a similar topic and nature, the differences are dramatic in their experiments, format and overall conclusions. In 2003, Santarelli et al. proposed that neurogenesis is the mediating action between antidepressants and their behavioral effects. While Santarelli used behavioral, molecular and anatomical data to prove this, it is hard to find the argument convincing. The first point of criticism would be the animal model, and it's lack of clinical translatability. The mice used in the study were not subject to any sort of stress or depression standard before being treated with anti-depressants. While the study still measured the effects of anti-depressants in a stressful behavior task, it can be argued that anti-depressants might act differently upon a "depressed" brain that is more representative (neuroanatomically, neurochemically, etc.) to a human. Additionally, Santarelli only used one behavior task, the novelty suppressed feeding task, to measure the behavioral effects of the anti-depressants. Not only does this experimental design lack thoroughness, but the NSF task is often thought of as a test for anxiety. While anxiety is a component of depression, the NSF test may not be enough to prove depression or alleviation of depressed symptoms. Santarelli did provide some evidence that neurogenesis occurred with anti-depressant therapy. However, the experimental design calls into question the validity of the conclusions.

In 2009, Bessa came back with what seemed like a vengeance on Santarelli's theories. Bessa et al. hypothesized that anti-depressant action is not dependent on neurogenesis but neuronal plasticity instead. From this theory, Bessa designed a thorough study to observe the behavioral, anatomical and genetic basis behind anti-depressant mechanisms. While Bessa provided several quality experiments, the format in which they were presented was not as fluid as Santarelli's. Bessa, with a lot of data, overwhelmed the reader with procedures and details that were hard to keep track of. Personally, I found myself having to read the paper multiple times with varying perspectives (in detail, big picture, etc.) to try and find the reasoning behind each of the experiments and the story each one told. However, by the end, I realized that Bessa told a convincing story on anti-depressants and its independence from neurogenesis. However, conclusions were still slightly unclear indicating that neurogenesis did occur with anti-depressants but may not be the mechanism by which anti-depressants act. 

Both papers have some validity. However, I can't help but feeling that even through the multitude of experiments and discussions, I have gained only a little understanding of the true mechanisms behind anti-depressants and their alleviation of behavioral depressive effects.