Fig. 8. A-mediated Tiam1 activation is affected by Ca²⁺ signaling. (A) Time lapse experiments were performed to analyze the Ca²⁺ increase in hippocampal cells after A_1-42 addition, using the fluorescent tracer Fluo3-AM. (B) Phospho-Thr levels from total immunoprecipitated Tiam1 were tested by immunoblot, in neurons treated with A_1-42 in the presence of BAPTA-AM; ^*P<0.05. (C) Hippocampal neurons stimulated with A_1-42 were analyzed for Tiam1 association to active Rac1 after BAPTA-AM or Gö6976 treatments. Rac1 was pulled down using PAK-PBD agarose and the co-immunoprecipitated Tiam1 was tested by immunoblotting using anti-Tiam1 antibody. Values were normalized against total Tiam1 in the crude homogenized. ^*P<0.05.