Isotretinoin and retinoid receptors in brain confusion?

I am considering starting a treatment with Accutane(Isotretinoin), however I am not sure about what the effects on the brain are. Here are two studies that contradict each other:

http://www.ncbi.nlm.nih.gov/pubmed/11696672
The first one states that using an antagonist, they increased the rats’ working memory. So logically, using the agonist (isotretinoin), it would cause a loss of working memory?

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3360864/
Here they state that not only did isotretinoin not have negative effects, but it actually had positive effects.

I am more inclined to believe that it has negative effects, because most anecdotal evidence says that it makes patients feel “foggy” and “forgetful”. Can anyone please enlighten me? What exacly does this stuff do to the brain and is it irreversible?