BDNF induces the proteolytic processing of ApoER2 in cortical neurons. (A) Cortical neurons (DIV 7) were treated with 100 ng/mL BDNF for 30 min. AKT phosphorylation levels shown are a result of TrkB activation by its ligand BDNF. Actin is shown as a loading control. (B) Immunofluorescence detection of ApoER2 in permeabilized cortical neurons from rat embryos using an antibody directed against the cytoplasmic domain of the receptor. (C) Serum-starved neurons were pre-treated with 10 μM DAPT for 1 h and then incubated with 100 ng/mL BDNF for 5 h. ApoER2 was recognized from cell lysates using an antibody directed against its intracellular pro-rich region. α-tubulin is shown as a loading control. (D) The blot levels of ApoER2 CTF were normalized to the loading control α-tubulin and plotted as the average ± SD of three independent experiments. Student’s t-test, *P < 0.05.