ApoE isoform expression does not affect apoER2 expression levels. Representative western blots showing levels of apoE (A) and apoER2 (B) immunoreactivity in whole hippocampus of aged animals. Quantification of immunoreactivity standardized to actin (n = 8, n = 5 for apoE3 TR). C57BL/6J (WT, white), apoE-deficient (E0, light grey), apoE2 TR (E2, medium grey), apoE3 TR (E3, dark grey), apoE4 TR (E4, black). Data expressed as mean ± SEM.