Acute EHT treatment prevents Aβ-induced impairment of long-term potentiation.

<p><b>(</b>A-F) Time course of averaged Schaffer collateral fEPSP responses (± SEM) in hippocampal slices prepared from slices treated with vehicle or 0, 0.0001, 0.001, 0.01, 0.1, or 1 μM EHT +/- vehicle or 100 nM Aβ (horizontal bar) 20 min prior to delivery of theta-burst stimulation (arrow). (A) Aβ treatment significantly reduces potentiated responses following TBS in slices treated with 0 μM EHT (2-way RM-ANOVA for treatment with time and treatment as factors: F(1,19) = 8.827, P = 0.0078). (B) Aβ treatment significantly reduces potentiated responses following TBS in slices treated with 0.0001 μM EHT (2-way RM-ANOVA for treatment with time and treatment as factors: F(1,11) = 6.84, P = 0.0240). (B) Aβ treatment yields a non-significant trend for reduced potentiated responses following TBS in slices treated with 0.001 μM EHT (2-way RM-ANOVA for treatment with time and treatment as factors: F(1,16) = 2.123, P = 0.1645). (D-F) Aβ treatment does not significantly reduce potentiated responses following TBS in slices treated with 0.01, 0.1, or 1 μM EHT (2-way RM-ANOVA for treatment with time and treatment as factors: For 0.01 μM EHT: F(1,18) = 0.1646, P = 0.6898; For 0.1 μM EHT: F(1.21) = 0.0034, P = 0.9543; For 1 μM EHT: F(1,15) = 0.0014, P = 0.9702). Comparison of potentiated responses in the absence of Aβ revealed no effect of EHT treatment alone on TBS-induced LTP (2-way RM-ANOVA comparisons to 0 EHT + vehicle for treatment with time and treatment as factors: For 0.0001 μM EHT: F(1,15) = 0.0132, P = 0.9099; For 0.001 μM EHT: F(1,18) = 0.0539, P = 0.8191; For 0.01 μM EHT: F(1,18) = 0.16, P = 0.6939; For 0.1 μM EHT: F(1,21) = 0.2294, P = 0.6369; For 1 μM EHT: F(1,18) = 0.7098, P = 0.4106). (G) Plot of the average potentiated responses over the last 10 min of the recordings shown in B-F for slices treated with Aβ in the presence of the indicated concentrations of EHT. The upper and lower dashed lines indicate the mean potentiated response obtained in the absence of EHT for vehicle or Aβ treated slices respectively. (N = 11 0 μM EHT + vehicle, 10 0 μM EHT + Aβ, 6 0.0001 μM EHT + vehicle, 7 0.0001 μM EHT + Aβ, 9 0.0001 μM EHT + vehicle, 9 0.0001 μM EHT + Aβ, 9 0.01 μM EHT + vehicle, 11 0.01 μM EHT + Aβ, 12 0.1 μM EHT + vehicle, 11 0.1 μM EHT + Aβ, 9 1 μM EHT + vehicle, 8 1 μM EHT + Aβ slices).