As a continuation of the schizophrenia model, this week's papers focused on the involvement of a DISC1 mutant (Ayhan et al., 2011) and a deficiency in metabotropic glutamate receptor 5 (Burrows et al., 2015) in schizophrenia. To begin with Ayhan et al., I thought they overall had a good argument. I believe they included effective controls throughout their experiment. Since DISC1 is involved in both brain development and adult brain function, it was good that they tested the mutant gene both prenatally and postnatally. In addition, since schizophrenia is so complex and does not target just one neurotransmitter, I thought they did a good job testing the effects of a variety of monoamines that could all have links to schizophrenia. They could have been a little more consistent with including whether they used males or females in their figures, however. In Figure 3, they should have also included experiments done on female frontal cortices, rather than just males, as well as male hippocampuses, rather than just female ones. Finally, since schizophrenia typically affects human adults, this experiment should have been more specific about the postnatal expression in mice and done more tests or used more controls to clarify this.
My favorite aspect of Burrows et al. was their inclusion of how the environment interacts with genetic predisposition in the schizophrenia model. The fact that environmental enrichment can improve schizophrenia-like behaviors in a variety of different behavioral tasks (and, in some cases, improve so much that the KO matches the WT like in Figure 2b/c) in mice can be extremely useful in studying the onset, progression, and treatment of schizophrenia in humans. In this paper, they exposed the mice to EE prior to the different behavioral tests, so I wonder if the exact time you are exposed to EE makes a difference on behavior... is it just right before the test or can it be long before? What about exposure after a test, and then a re-test to measure if that had an effect? Maybe they can examine this in a future experiment.
(also, who thought it was a good idea to make the KO EE line in Figure 1 whitish gray? You can't even see it!!)