All values are expressed as means ± standard error (SE) of n observations/group. Analysis of co-localization was performed using Pearson's correlation coefficient. Comparisons of more than two groups were made with a one-way ANOVA using post-hoc Tukey's test. Comparison of two groups was obtained by the Student's t-test for unpaired data when appropriate. Differences were considered statistically significant at values of P < 0.05.