values were subtracted for statistical analysis. Cell counts were conducted as previously described (Goodson and Wang, 2006; Goodson et al., 2009a). All cells were counted in each relevant section for smaller cell groups and are represented as number of cells per section/gram body weight. TH-ir cells in the VTA were counted within a standardized box and are represented as number of cells per 100 μm2.
All ANOVAs, regressions, and PC analyses described in the Results were conducted using Statview 5.0 for Macintosh. Given the large number of analyses, some concern arises with regard to type I error, although all brain areas and neurochemicals examined here are known a priori to be relevant to social behavior (although not in all possible combinations). Corrections for multiple comparisons in such instances are usually too conservative and not appropriate (Rothman, 1990), and we therefore do not emphasize them in our interpretations. However, they may still provide a useful metric for evaluation; thus each of our data tables and figure panels provides information on significance relative to Benjamini-Hochberg corrections for the false discovery rate (Benjamini and Hochberg, 1995). Corrections were applied to each set of ANOVAs (e.g., for VT measures across all brain areas) and to each corresponding set of regressions. Again, though not emphasized in the Results, the robustness of our findings is notable; for example, 73 of 78 ANOVAs that yield P values < 0.05 were significant following corrections. Note that although the Benjamini-Hochberg correction initially applies a Bonferroni criterion, it adjusts α in a stepwise manner for remaining tests as long as P values continue to be significant at each step.
We thank Francisco Ayala, John Avise, and Georg Striedter for inviting this contribution; Jacob Callis, Brian Gress, Alexis Howard, Aubrey Kelly, Melissa Knisley, and Brittany Welsh for assistance with immunocytochemistry and/or cell counts; Ellen Ketterson, Dawn O’Neal, and Ryan Kiley for assistance with collections; and Drew King and Meredith West for property access; Harold Gainer for the donation of antiserum. Support for this study was provided by Indiana University.