AU impossible at this time.4Interpretation of adolescent MRI/fMRI research. As with all neuroimaging studies that compare groups, there is no clear way to interpret differences in brain structure and function between the two groups. For example, we are still far from understanding whether higher volume or activation in one group compared with another is “good” or “bad”. Higher levels of activation in the AU group could be interpreted as representing compensatory mechanisms, while lower activation may represent less neural engagement or less recruitment of necessary brain systems. Furthermore, it is not possible to know what differences in GM or WM correspond to at a cellular or synaptic level. Smaller GM volumes have often been interpreted as reflecting cell loss, potentially specifically in the form of glutamate-mediated excitotoxicity, upregulation of inflammatory mediators, synaptic loss, alterations in glia and/or white matter pathology that leads to cell absence or loss (Medina et al., 2008; Scholz, Klein, Behrens, & Johansen-Berg, 2009). However, all interpretations at this point are purely speculative, made with a degree of bias that alcohol must be having a deleterious effect. Thus, we have to be cautious when attempting to interpret differences between groups. Animal studies are one important avenue that
