Fig. 3.

Treatment of Psen1−/− primary neuronal cultures with recombinant reelin induces normal Dab 1 phosphorylation. Primary neuronal cultures were treated with supernatants from reelin transfected or mock-transfected HEK cells. Results from a representative experiment are shown in panel A. The apparent increase in p-Dab1 in the Psen1−/− mock treated at 45 mins represents a loading effect. In (B) the fold increase in Dab1 phosphorylation is expressed as the ratio of p-Dab1 to total Dab1. Results are presented ± the standard error of the mean and represent averages from three-six independent experiments for each time point. Responses in wild type (wt) and Psen1−/− cultures were compared at each time point using unpaired t-tests. There were no significant differences at any of the time points (p values 0.10 to 0.46). In panels C–E, primary neuronal cultures were stimulated with reelin or control supernatant for 30 mins in the presence or absence of the PI3K inhibitor LY294002. Representative Western blots from studies that were performed multiple times are shown probed for phospho-Dab1/total Dab1 (C), phospho-Akt (p-Akt)/total Akt (D), and phospho-GSK-3β (p-GSK-3β/total GSK-3β (E).