Percent of neurons in dissociated hippocampal cultures containing rods as a function of Aβ form, concentration and time of treatment. (A) Dose-response curves for Aβsyn oligomers and Aβd/t versus control. The concentrations are expressed in terms of the 7PA2 CHO cell secreted concentration of Aβd/t (1X = 250 pM), which was used at 0.1, 0.5 and 2X this value. For the Aβsyn oligomers, the 1X value equals 1.0 μM. (B) Following treatment with 1X amounts of Aβd/t or Aβsyn oligomers, neurons were fixed at the times shown and the percent of neurons with rods was quantified. By 2 h the percent of neurons forming rods in response to Aβd/t was significant (*) over controls (p = 0.05). The Aβsyn-treated neurons required 6 h to reach significance over controls. Significance (# = p = 0.05) in the differences between the two Aβ species occurred at 8 h.