Columns depict latency taken to enter the dark chamber before and after foot shock (trial and test, respectively). 24 hrs after icv injection of ACSF (sham treatment) animals were trained and IA memory task was tested 3 hrs after foot shock (column 1 trial, column 2 test). E2 was subcutaneously injected (300 µg/kg) 1 hr before the trail and animals were tested 3 hrs after the trial [column 3 and 4]. 24 hrs after icv injection of Aβ1–42 oligomers (0.5 µM) memory task was tested as described above (column 5 trial, column 6 test). For treatment with Aβ and E2 the above protocol was again followed (column 7 trial, column 8 test). Data are mean ± SEM. *, p<0.05, versus groups connected by bars as determined by unpaired t test, n=12 (12 animals per group).