Week 3: Pollack and Li

The Li et al (2011) and Pollack et al (2008) articles both investigate animal models of depression, using vastly different approaches. The Li et al article proposes that NMDA receptor antagonists and pharmacological agents such as ketamine can have great antidepressant effects on animal models. However, the Pollack et al. (2008) article focuses on a behavioral antidepressant, learned safety. It is very interesting to me that something that can simply be learned by an animal can serve as a way to lessen depressive symptoms in that animal.

            The Li et al article seems more in depth in its investigation, and the experiments they conducted to prove their point seem more thorough than the Pollack et al article. The fact that they were able to find that NMDA antagonists such as ketamine can be effective after a single dose and that they act very quickly would be extremely useful for humans suffering from depression, who as of now generally need to wait weeks for their antidepressants to kick in. The Li et al article also goes in depth into the pathway that is affected by NMDA receptor antagonists, and shows that disruption of this pathway leads to a reversal of the antidepressant effects of the drugs. It is also important that Li et al found that the actions of NMDA receptor antagonists were long lasting after just a single dose.

            The Pollack et al article seemed slightly far-fetched. Although it is interesting that a learned behavior can serve as an animal antidepressant, it would be highly unlikely that a similar learned behavior/response would allow humans to yield similar antidepressant effects. It would be extremely difficult to use an experiment such as the one proposed in the Pollack et al article on human subjects, given that in order for the antidepressant actions to occur there has to be a conditioned fear and safety response.  The most interesting aspect of the Pollack et al article, however, was the fact that the learned safety paradigm caused an increase in the survival of new neurons of the hippocampus.