Fig. 7

AP properties are differently influenced by sex and transgene expression in EC from 20-month-old mice. a An example of a recorded EC neuron following an injection of a 3-s depolarizing current. In this typical trace, the injected current triggered three APs. b Representation of a post-spike hyperpolarization (zoomed from the dashed square in a). Post-spike hyperpolarization was calculated from the difference between the voltage undershoot after the AP (the dashed line) and the voltage peak of post-spike. c Representation of AP characteristics quantified in this study (zoomed from the dashed square in the panel b). Undershoot was the difference between stabilized voltage after the AP and activation threshold. d AP threshold was significantly decreased with transgene expression in both sexes. e Amplitude of AP was higher in neurons from male 3xTg-AD, compared to those from male NonTg and female 3xTg-AD. f Transgene expression reduced undershoots only in the male. The rising slope was lower in NonTg males (g) whereas decay slope was higher in both NonTg and 3xTg-AD male mice (h). Transgene expression reduced post-spike hyperpolarization in both sexes. The number of mice included in each group was 5 for NonTg males, 12 for 3xTg-AD males, 8 for NonTg females, and 6 for 3xTg-AD females. Statistical comparisons were performed using two-way ANOVA (d, h, and i) or unpaired Student’s t test (e, f, and g). Abbreviations: AP, action potential; EC, entorhinal cortex. *p < 0.05, **p < 0.01, ***p < 0.001