Data are presented as mean ± SEM. SigmaStat software (Aspire Software International) or the GLM procedure in SAS v.9.2 (SAS Institute) was used to analyze data. In brief, data were evaluated via analysis of variance (ANOVA) followed by Tukey post hoc comparisons. Some data was analyzed with a Student's t-test with a Bonferroni correction for multiple comparisons. Some data was processed with non-parametric statistics when tests for normality failed.
